Precision Sensing

Volume 2

Inertial Sensors and Rugged ElectronicsApplications and Integration

Bringing innovation and reliability to the warfighter

Budget cuts and sequestration have made navigating the defense market more complicated, but they have also spurred more use of innovative technology from the commercial world. Regardless of platform or program, defense customers are leveraging more and more commonality and commercial-off-the-shelf (COTS) technology in their systems to enable lower life cycle costs while enhancing warfighter capability and maintaining and edge on the battlefield.

From navigation sensors to displays to rugged computing, defense customers demand suppliers deliver repeatable per-formance, obsolescence management, and field application engineering support. They want a partner that can leverage commercial technology in systems and in packages that comply with the military’s stringent mission requirements and meet the ever-growing demand for reduced size, weight, power, and cost (SWaP-C) in every application.

Military mission requirements have only gotten tougher. Precision, accuracy, and reliability are critical whether the applications are unmanned systems, laser targeting, or com-munications and positioning.

Companies that answer this chal-lenge, such as Sparton Navigation and Exploration (NavEx), not only have a legacy with the Department of Defense (DoD) of providing that capability, but they also have the manufacturing infrastructure to battle obsolescence, managing the total lifecycle cost of a product.

In the following pages you will learn how Sparton delivers cost-effective capa-bility to its customers through product lifecycle management while meeting tough SWaP-C requirements. Readers will also discover the latest innovations in auto-calibration technology in digital compasses and inertial systems, inertial measurement units (IMUs), attitude heading and reference systems (AHRS), and compass technology.

We encourage you to dive into our con-tent, learn about our inertial systems, advanced acoustic sensors, laser tar-geting technology, but also our display expertise. Our knowledgeable and highly experienced engineering team is always available to help you integrate our solutions into your applications.

Learn More

2 Bringing innovation and reliability to the war�ghter

4 Military targeting systems

6 Auto-calibration technology in digital compasses and inertial systems

8 What is an IMU?

9 What is an AHRS?

11 Q & A with Mike BagleyProduct Manager, Sparton Navigation and Exploration

14 Choosing a display partner:5 important characteristics

17 Why rugged PCs are important in military systems

18 SWaP-C and why yourcomponent partner matters

21 Compass terminology

22 What’s wrong with this compass?

23 Videos

24 Solutions

26 Products

PG 9

PG 14

PG 4

Precision Sensing | Volume 2 | 3

Leveraging optimized SWaP-C navigation components for military applications

Precision Sensing

Volume 2

CONTENTS

Military targeting systems require maximum accuracy at all times and under all conditions. These systems can be hand-held or mounted on various vehicles or weapons, but they all must per-form reliably and consistently in order to meet the needs of the soldier of today and tomorrow.

Heading and elevation are critical factors in accurate targeting systems. The complex nature of these systems can present signi�cant challenges in achieving maximum accuracy quickly,

reliably, and repeatedly. Magnetic disturbances, whether pro-duced by external sources or internal to the targeting system, can cause considerable errors in the output of conventional digital magnetic compasses (DMCs).

A complete inertial system that integrates MEMS-based inertial sensors, magnetometers, and advanced algorithms to process and fuse sensor data is required to overcome the difficulties inherent to traditional DMCs in complex applications such as

4 | Volume 2 | spar tonnavex.com

MILITARY TARGETING SYSTEMS

targeting systems. All of this must be accomplished in a small, lightweight package with minimum power consumption, the ever present demands of SWaP-C – small Size, light Weight, low Power, and low Cost.

ADDRESSING THE CHALLENGES OF MILITARY TARGETING SYSTEMSOver the past several years Sparton in De Leon Springs, FL, has developed an in-depth understanding of the complexity, the challenges, and the requirements of military targeting systems. Sparton’s line of inertial sensor systems offers complete and integrated solutions that not only deliver accurate heading and platform attitude data, but many additional features.

Leading-edge MEMs-based gyros allow for heading stability in the presence of transient magnetic disturbances. These tri-axial gyros and accelerometers provide inertial data that eliminates the need for an additional inertial measurement unit (IMU).

Sparton’s proprietary AdaptNav™ sensor fusion algorithm provides real-time optimization of sensor performance in varying magnetic and dynamic operating environments. It provides real-time platform “noise” characterizations used for drift compensation of heading, pitch, and roll when systems are in electrically or mechanically “noisy” environments. Sparton’s NorthTek™ embedded program-ming platform provides limitless output customization as well as additional processing capability that can be utilized to offload var-ious system integrator-processing requirements. NorthTek™ can be thought of as a new way for customers to write custom apps that can be downloaded to the inertial sensor system.

Simple and fast in-�eld calibration ensures rapid system avail-ability and maximum accuracy. Multiple data outputs for calcu-lation of heading accuracy Figure of Merit (FOM) and in-�eld calibration quality. An optional “strapped down” precision mount with a �ex cable connection provides optimum accuracy and

allows for �exibility in positioning the device within the targeting system’s housing.

In fact, FOM and the precision mount option were both spe-ci�cally developed by Sparton working with targeting system integrators. Sparton has an established history of a willing-ness and �exibility to work with customers and end users in the development of technological improvements and product modi�cations. They call this Voice of the Customer (VOC) and they do listen.

All of this is achieved in a form factor that is less than 0.8 in 3, weighs only 16g, and consumes 330 mW. This is not a conven-tional DMC. It is truly a state-of-the-art, integrated sub-system that provides heading, pitch, roll, and inertial data outputs while minimizing size, weight, power, and cost.

TARGETING SYSTEM APPLICATION: CLRF ICIn late 2012, the U.S. Marine Corps solicited four military electro-optical companies to develop a handheld tactical laser range-�nder that would be small enough for soldiers to carry and would help detect, identify, and pinpoint targets day or night, in good weather or bad. The product is called the Common Laser Range Finder Integrated Capability (CLRF IC).

The CLRF IC system was required to weigh no more than three pounds and provide improved integrated night-vision capability, internal selective availability anti-spoo�ng module (SAASM) GPS, and both magnetic and non-magnetic heading capability. Replacing the previous CLRF equipment, the CLRF IC requires weight reduction, enhanced precision, improved night-vision capability, and improved magnetic and non-magnetic heading capability by incorporating components of the CLRF suite into one system, the CLRF IC system.

The CLRF IC is a handheld, lightweight man-portable GPS target location device to assist a soldier in determining the loca-tion of a target or other object of interest by measuring the dis-tance, direction, and elevation angle from the operator to the object. The system can operate in the daytime and at night, as well as a wide range of environments.

SUMMARYSparton has worked closely with prime contractors on technolog-ical advancements and product enhancements. This willingness to be �exible, to think outside the box, to modify and improve products for the speci�c application of mili-tary targeting highlights Sparton’s desire to be disruptive – disruptive in its products and their features as well as disruptive in the success of the partners with whom they work.

Precision Sensing | Volume 2 | 5

Auto-calibration technology in digital compasses and inertial systems

Conventional digital magnetic compasses require a complex and cumbersome “in-�eld” calibration process.

Most users, including the military, do not embrace this calibration – commonly referred to as the “Kabuki

Dance.” It is often performed improperly, incompletely, or sometimes not at all. This results in diminished

sensor performance and poor overall accuracy, in targeting and other applications. Field calibrations are

vital to account for changes in magnetic signature of the system platform. This signature can change over

time due to variables including installation of new batteries, different system modes (day/night), or residual

magnetic charging of internal components.

Sparton has developed a new calibration mode that utilizes the motion of the host device to collect and process calibration mea-surements in real-time. This “auto-calibration” mode dramatically simpli�es the calibration procedure while maintaining good overall performance and accuracy. While not designed to totally eliminate the manual in-�eld calibration, it can be used as the sole method of calibration should a manual calibration not be possible. Best results will be obtained when the “auto-calibration” mode is used to build upon a previously performed manual calibration.

Sparton designs and manufacturers integrated, MEMS-based inertial systems for precise measurements of direction and plat-form attitude (heading, pitch and roll). These systems provide enhanced capabilities and proprietary features that surpass the conventional digital magnetic compass (DMC).

Recent product advancements, such as the AHRS-8P (see image), designed speci�cally for Targeting Sensors have shown positive results and acceptance by the industry. These have included:

› An enhanced calibration algorithm allowing limited pitch & roll operation and reduced convergence time

› A “non-magnetic” mode allowing operation using only the inertial sensors (accelerometers & gyros)

› Figure-of-Merit indicators for estimated heading accuracy and quality of calibration

› Precision mounting option for remote location of the device within the host system to minimize magnetic errors

Sparton’s latest development is a next generation product providing signi�cant SWaP-C reductions and a breakthrough calibration method. The Sparton AHRS-M1 offers functionality comparable to our current products with the addition of an “auto-calibration” mode. The smaller form factor of the AHRS-M1 also signi�cantly reduces its size and weight (see comparison between the AHRS-M1 with AHRS-8).

AHRS-M1 Compared to AHRS-8

Model AHRS-8P

Mapping of targeting sensors helps to maintain accuracy.

6 | Volume 2 | spar tonnavex.com

DIGITAL COMPASSES

TECHNICAL BACKGROUNDSparton’s AHRS-M1 utilizes innovative magnetic mapping (see mapping image of uncalibrated and calibrated mapping) and advanced adaptive algorithms to maintain overall system accuracy in real-time. The device offers two calibration modes: Precision Manual Calibration and the new Autonomous mode called Auto-Calibration I.

Autonomous calibration frees the user from the periodic calibrations necessary to keep a system at optimal performance over extended periods of time. During normal movement of the product, the autonomous calibration algorithm will automatically select points to insure spher-ical diversity and start converging to a solution when an adequate number have been collected (see image AHRS-M1 in auto-calibration mode). The solution is further refined in real-time when new measurements are received without any intervention from the user.

Precision manual calibration offers the user the ability to calibrate the system once and retain that calibration for future use (see Figure below). The maximum number of measurements has been increased from 12 to 32 to allow for more detailed calibrations in applications that may have a highly distorted magnetic environment. Users can take measurements in any orientation as long as the points are spatially diverse and not limited to one direction. For a good calibration, the device must be able to “see” the Earth’s magnetic �eld from different orientations in order to know what the magnetic distortions look like in 3-dimensions. The precision calibration runs the same adaptive

algorithm to solve for magnetometer errors as the autonomous calibration. The user can also select what action the algorithm takes once convergence to a solution has been achieved. The manual calibration can either turn itself off after convergence, stay in the manual calibration mode waiting for additional mea-surements while continuously converging, or transition to the autonomous calibration.

Auto-calibration software stores calibration for future use.

Precision Sensing | Volume 2 | 7

What is an IMU?

An Inertial Measurement Unit, commonly known as an IMU, is an electronic device that measures and reports orientation, velocity, and gravitational forces through the use of accelerometers and gyroscopes and often magnetometers. IMUs are a main component of the inertial navigation systems used in aircraft, unmanned aerial vehicles (UAVs) and other unmanned systems, as well as missiles and even satellites. The data collected by an IMU is processed by computers to track posi-tion through dead reckoning. Common applications for IMUs include control and stabilization, navigation and correction, measurement and testing, unmanned systems control, and mobile mapping.

In an inertial navigation system, the data collected and reported by an IMU is processed through a com-puter in order to calculate current position based on velocity and time. Velocity and time calculations can be used to provide dead reckoning. For example, if a system such as an aircraft travels north at 100 miles per hour, it can be deduced that the system is now 100 miles north of its initial location. Combining this “simple” logic to a system of maps can show where a system is on map similar to GPS, but without the need to be connected to or in commu-nication with any outside systems. This is the process known as dead reckoning.

All navigation systems, including IMUs, demand very precise gyroscopes, as it is the quality of these devices that greatly impact the overall performance of the inertial sensor system. An example of a very high-end gyroscope is the ring laser gyro-scope (RLG). RLGs are generally considered to be the most accurate option, but they are also very expensive. A lower cost alternative to the more expensive RLG is the �ber optic

gyroscope (FOG). FOGs pro-vide extremely precise rota-tional rate information due to their lack of moving parts. However, FOGs have a great deal of inherent development and manufacture costs as well as a larger form factor and higher power demands.

As technology improves, FOGs now have even lower cost competition. Micro Electro-Mechanical Systems (MEMS)-based gyroscopes have closed the perfor-mance gap on some FOGs and when factoring in their lower cost and power require-ments, MEMS-based devices provide an excellent answer for the need of precision in gyroscopes and naviga-tion systems such as IMUs. MEMS-based systems are not only less expensive, they are generally small, rugged, and consume less power – providing great potential for miniaturized solutions.

THE SPARTON IMU-10Sparton Navigation and Exploration (Sparton NavEx) IMU-10 is a reliable high-per-formance, high-accuracy 10 DOF inertial sensing package in a ruggedized enclosure. High speed, synchronous sampling of all inertial sys-tems combined with high rate coning and sculling compen-sation makes the IMU-10 the perfect solution for high accu-racy inertial navigation.

IMU-10

Learn More �

8 | Volume 2 | spar tonnavex.com

INERTIAL MEASUREMENT UNIT

An Attitude Heading and Reference System, better known as an AHRS, is a 3-axis sensor system that

provides real-time 3-D attitude position – pitch, roll, and heading (yaw). The primary function of an AHRS is

to provide orientation data. AHRS are designed to replace traditional gyro-based instruments and to provide

superior reliability and accuracy.

What is an AHRS?

Precision Sensing | Volume 2 | 9

ATTITUDE HEADING AND REFERENCE SYSTEM

Some of the many applications for AHRS include control and stabilization, measurement and correction, and navigation. An example of control and stabilization could be where a camera or antenna mounted on a system such as a plane or ship needs to be stable. Measurement and correction best applies to imaging systems where an AHRS is used to ensure the direction the imager is pointed. And in navigation, an AHRS can be used to provide orientation and direction.

AHRS consist of magnetometers, micro-electromechanical sys-tems (MEMS) accelerometers, and MEMS gyroscopes on all three axes. In other words, a MEMS-based AHRS includes sen-sors for 3-axis magnetic, 3-axis acceleration, and 3-axis gyro. These sensors, combined with a built-in processor, create an inertial sensor system fully capable of measuring the attitude of objects in 3-D space.

The sensors in AHRS use algorithms to estimate this attitude in 3-D space. Some AHRS units will use traditional Kalman �lter algorithms that use magnetic and acceleration measure-ments to estimate the time-varying gyro bias in real-time. Other AHRS systems utilize modi�ed non-Kalman �lters that compute an estimation of orientation in real-time. A potential advantage of these modi�ed algorithms is that they can outperform tra-ditional Kalman �lter-based sensors by providing real-time optimization of performance for varying magnetic or dynamic operating environments.

Magnetometers are used in AHRS to measure the direction of the magnetic �eld at a point in space. A more traditional

magnetometer would be a �uxgate system. Though this tech-nology provides good accuracy and reliability, it is not condu-cive to a MEMS-based AHRS due to its larger form size and greater power requirements. An alternative to �uxgate tech-nology is a magneto-inductive (MI) sensing technology. Not only does this technology provide the desired smaller form factor and low power requirement, MI also provides very high resolution – higher than what competing technologies such as anisotropic magneto resistive (AMR) sensors can provide at similar cost.

Accelerometers measure proper acceleration – the rate at which the velocity of an object is changing. They measure the static (gravity) or dynamic (motion or vibration) acceleration forces of a given object. The ideal accelerometer in an AHRS provides long-term stability, low vibration error, and reliability.

AHRS demand very precise gyroscopes as the quality of these devices greatly impacts the overall performance of the inertial sensor system. An example of a very high-end gyroscope is a �ber optic gyroscope, commonly known as a FOG. FOGs pro-vide extremely precise rotational rate information due to their lack of moving parts. However, FOGs have a great deal of inherent development and manufacture costs as well as a larger form factor and higher power demands. As technology improves, MEMS-based gyroscopes have closed the performance gap on some FOGs. When factoring in lower cost and power require-ments, MEMS-based devices provide an excellent answer for the need of precision in a gyroscope.

MEMS-based AHRS continue to develop and improve in both technology and application. As the requirements of both military and commercial systems evolve, there is increasing demand for continuous improvement. Both existing systems and those in development must incorporate size, weight, power, and cost (SWaP-C) standards. Simply put, demand will increasingly require systems and their components to be smaller, lighter, use less power, and all at a lower cost. AHRS are no different in this initiative. Manufacturers must adhere to these principles, all while improving the performance of AHRS. Manufacturers who fail to adjust to these demands will �nd themselves left behind.

THE SPARTON NAVEX AHRS-8Sparton Navigation and Exploration (Sparton NavEx) offers the AHRS-8 as a fully temperature compensated Attitude Heading and Reference System (AHRS), individually cali-brated over the -40 °C to +70 °C operating range. It delivers heading accuracy in a broad range of challenging dynamic and magnetic environments.

ATTITUDE HEADING AND REFERENCE SYSTEM

AHRS-8 Learn More �

10 | Volume 2 | spar tonnavex.com

ATTITUDE HEADING AND REFERENCE SYSTEM

Q & A with Mike Bagley Product Manager, Sparton Navigation and Exploration

Q: Please provide a brief description of your responsibilities within Sparton and what is the NavEx role within the larger parent company, Sparton?

BAGLEY: I’m the product manager for Sparton Navigation and Exploration, called NavEx. We provide inertial sensors and compass solutions for many military and industrial applications. Some of my responsibilities are de�ning the product vision, the product roadmap, managing the product life cycles, managing research and development, product support, marketing and competitor analysis, overseeing the product P&L pro�t margins, and aligning our products to our customers’ requirements, so that we can continue to deliver winning best-in-class products.

We are a business platform called Precision Sensing and Measurement, or PSM, in the business segment of Engineered Component Products (ECP). Our DeLeon Springs, Florida facility also includes Anti-Submarine and Undersea Warfare Solutions (UWS), which manufactures sonobuoys and other solutions for the Navy. For NavEx, our customers are typically the Army, Marines, and other industrial and commercial mar-kets. We provide technical support, engineering planning, and resources for independent proposals and also have a design role for joint product development efforts within Sparton. NavEx provides contributing elements that complement UWS products and ultimately produces quality solutions for our customers.

Q: What types of military platforms are Sparton inertial sensor products currently deployed on and which types of applications are the best �ts for Sparton products?

BAGLEY: We’re currently on military applications that involve heading, pitch, and roll. Examples include targeting platform stabilization applications, antenna positioning, and other types of products that are used by the war�ghter. We’re in fast deploy-ment applications for �rst responders, as well as commercial and non-military applications for underwater exploration. Of course, we’re in autonomous vehicles too, primarily ground and under-water. Best �ts are de�ned by the dynamics of the platform. So, is the platform vibrating, is it moving or is it stationary? We have products that are designed to meet these requirements.

Another unique feature of our products is NorthTek™ script, which allows our end users to program our devices to best suit the dynamics of their platform. For instance, if they know their platform is going to �ip over and they wanted to know when that actually occurred, they can write a script that could throw an output when that condition happened, so that they would be alerted to when their vehicle was upside down. There are also options where they can control what sensors on the device are fused together and control those outputs. You can also program what kind of communication protocol is used for outputting the inertial sensor information. This gives us a competitive edge, because we can be really close to a drop-in replacement for a competitor’s product, where we can clone a communication protocol application that allows our customer to easily swap our products into their design.

Q: How does the military market perform for Sparton when compared to other markets like industrial or commercial? Are there similar requirements?

BAGLEY: At Sparton, we pride ourselves on delivering quality products to our military markets. We �nd it’s extremely impor-tant for the war�ghter to have a quality product with accurate and repeatable performance. With industrial and commercial markets, that same quality still has to be provided. We take all of our customers very seriously and we assist them with their design to ensure that they get the best performance capabili-ties possible in their design. Everyone’s concerned with on-time delivery, quality, exceptional customer service, and outstanding �eld application engineering support and that’s what we deliver.

Q: How does Sparton manage reduced size, weight, and power (SWaP) requirements from the military in their sensor solutions?

BAGLEY: Here at Sparton, we are vigilant in our design prac-tices. We continually look for improvement. We frequently look for components that meet military SWaP requirements. The MEMS component industry is constantly evolving, being driven by small handheld markets like cell phones and electronic note pads and we incorporate industrial grade versions of these MEMS into our products. As technology continues to improve, the size is

Precision Sensing | Volume 2 | 11

INTERVIEW

reduced, the weight reduced, the power needed is reduced, and all with increases in accuracy and performance. We look for ways to incorporate these advancements into our designs, so that we have a platform where we can scale and retro�t these bene�ts and features into our newer devices. The very nature of the industry that we’re in – MEMS-based sensors – is always getting smaller, faster, more accurate, and these technology improve-ments are passed on to our customers.

Q: What do you do to help manage obsolescence and total life cycle costs for your military customers?

BAGLEY: It’s one of our responsibilities during our initial design phase to look for components that have a long life cycle. In the event that a component does go obsolete, and they do, we �nd that we can react pretty quickly with a design change, and still have a drop-in solution replacement. We can manage total life cycle cost because we have options for last time buys. We know what the military program needs are and we have reserves and can make decisions based around those reserves to produce the same product, as expected during the life of the program. Also, our �rmware can be reprogrammed or upgraded by adding in desired features determined by the voice of the customer. We can enhance our products through �rmware upgrades that address the voice of the customer enhancements. If the cus-tomer has a version of �rmware that’s already spec’d in, then we have the logistics and capabilities to be able to maintain that version throughout the entire program lifecycle.

Q: Sparton recently acquired Stealth.com and Aydin Displays. How have those acquisitions added to your core competencies? How will they bene�t your customers?

BAGLEY: Stealth.com and Aydin Displays are product brands within our Rugged Electronics platform and in addition to adding their products to the overall product line of Sparton, they bring along some other skill sets through online web purchasing and e-commerce. We also share mutual customers and market space. We‘re working together to create blended solutions where we can capitalize on the core commonality between our groups and we feel that this will ben-e�t our customers by creating a one-stop shopping experience and being able to bring more value add to our customers’ programs. For instance, Stealth has a hardened computer and Aydin has hardened displays and we

have inertial sensors, so Sparton can offer a computer and display system with an embedded inertial sensor and that would be used on a deck or bridge of a boat or a ship. We share a lot of synergies that allow us to maximize these recent acquisitions.

Q: Looking forward, what will inertial sensor technology look like in �ve, or even 10 years from now? How will they evolve?

BAGLEY: Well, none of us have a crystal ball. But, if we just look at our core competency of heading and attitude outputs of a sensor, the technology evolving is within the MEMS and we were chasing accuracy and precision. But also, for instance, with gyro drift, we’re looking forward to MEMS that can be packaged with the same performance as a �ber optic gyro (FOG) or a ring laser gyro. These are tactical grade inertial navigation systems and I see that in the future the MEMS technology will get to the accuracies of these larger gyros and it’ll be at a signi�cant cost savings that we can pass through to our customers. For me, driving the product roadmap, I would like to think that we’re going to be using inertial sensors for things that we have yet to even think about. There are opportunities going forward, we could be part of the Internet of Things. We’re going to have sensors that are smaller, more accurate and use less power. There is always an opportunity to look at how sensors are fused together with multiple sensors, not just accelerometers and gyros, but you could have pressure sen-sors, temperature sensors that are all fused together all working in different ways.

This evolution of new MEMS technology and new applications comes from the young minds of our future. We have an engi-neering sponsorship program where we provide inertial sensors to young engineers that are thinking of new things that address

INTERVIEW

12 | Volume 2 | spar tonnavex.com

INTERVIEW

Homeland Security, harbor monitoring, underwater exploration, bottom node seismic monitoring for oil and gas �elds, and this technology as a whole. Also with more unmanned vehicles, more autonomous vehicles, come more opportunities for wire-less and a thing called swarming, where I can imagine in the future a military sortie �ies out over an operating theater for a military intervention and it will dump out a whole box of min-iature drones and they’ll all be communicating together and they’ll all be using inertial sensors. So, we’ll just have to watch and keep monitoring where technology is going. Sparton will be at the forefront of this innovation and help develop those prod-ucts and at the same time listening to the desires and needs of our customers, so that we can continue to be their strategic partners.

Q: You had mentioned FOGs. Is the term FOG killer, is that a reasonable term?

BAGLEY: There will always be a space for FOGs. There are FOG systems that cost millions of dollars that control extrater-restrial probes as they venture off to explore distant planets. I don’t believe within the next �ve years that MEMS will have that inertial tactical grade capability, but there are certainly classi�ca-tions of FOGs that are lower in performance and we are quickly stepping into that competitive space, that MEMS can compete directly with that level of performance.

Q:You mentioned the Internet of Things as one of the potential applications in the future what about opportunities like in the tracking and location of other individual war�ghters or assets?

Good question, typically these kinds of programs require a pull from a customer, it has to be a program of record. In some of these capabilities, as gyro performance becomes better and as fusion algorithms become better, there’s de�nitely a requirement for dead reckoning and GPS-denied environ-ments. So this question kind of revolves around what can we provide to the market where we are able to put a sensor on a war�ghter and monitor where those assets are. In the commercial world there’s already container shipping tracking where there are modules that are put on the side of a ship container with GPS and shock track sensors, accelerometers, thermometers, and pressure sensor. A customer can monitor their entire product as it’s being shipped around the globe and know how the container was handled or where it is. There’s surely going to be an opportunity to scale that concept down and put similar technology on a war�ghter.

Q: You mentioned Voice of the Customer; can you explain what you mean by that?

BAGLEY: Not all customers are the same. It’s important for us to recognize individual customers and we can align to help them achieve their own road map. That gives us the opportunity to adjust and improve to meet our customers’ needs. So we have an initia-tive called the Voice of the Customer where we collectively solicit requests for new features, what our customers would like to have, what are some things that we can do better, new things that maybe we don’t have that we can design, we call all of this the Voice of

the Customer. Periodically, we take this feedback and we release �rmware versions to address the inputs from our customers. These could be things where a customer’s trying to meet new require-ments for a program. For instance, there was a program recently where a customer needed some feedback if the sensor was being in�uenced by some external ferrous metal and we provided the vari-able that says that there was a potential here to see an anomaly, an outside force in�uencing the inertial sensor. So we were able to give that to them as a new output with a �rmware modi�cation. And there are many more examples that we roll out to our customers. But it doesn’t always have to be about �rmware. It could be just adding more value, like a blended solution combining our inertial sensors with some other part of their hardware and then we can provide the whole system calibrated together. We also provide contract manu-facturing and engineering services. We can go from the design of a prototype, all the way to fruition and then delivery of complete prod-ucts to our customers. It’s very important that we continue to rec-ognize that our customers have their own expectations and where they want to be and it’s my job and responsibility to make sure we can align to those customers and help them meet their goals.

I believe that great communication builds trust and solidi�es healthy and productive relationships. Businesses have to be vigilant when it comes to servicing customers. Their needs will evolve and we must be attentive and �exible to adjust to those customers’ desires. This behavior contributes to a win-win relationship and true partnerships. As an employee of Sparton, I have the unequivocal obligation to the company, to my employees, and to my customers to build trusting and respectful relationships. I believe, with con�dence, that investing in the success of my customer, I will also contribute to the success of Sparton.

“Not all customers

are the same. It’s

important for us to

recognize individual

customers and we can

align to help them achieve

their own road map.”

Precision Sensing | Volume 2 | 13

1 BROAD SELECTION OF PRODUCT SOLUTIONSBecause you want to be sure that you will be able to �nd a solution that meets all of your speci�c requirements, the supplier you select should offer a wide variety of ruggedized display solutions – both stan-

dard and custom products – as well as a number of potential enhancements. Choose a supplier that provides a selection of adaptable and customizable displays and offers you consultation to determine those critical requirements so your display can successfully perform in your unique environment.

5 THINGS TO LOOK FOR IN A DISPLAY SUPPLIERThere are hundreds of display manufacturers in the U.S. and thousands worldwide. Choosing a supplier with the appropriate speci�cations and experience will go a long way to ensuring a successful deploy-ment. The following are some key considerations to help you make this important decision.

Today, electronic devices are used in a variety of harsh environments in which they need to operate reliably

despite conditions such as strong vibrations, dust, dirt, moisture, and extreme temperatures.

While external housings are designed for this rough use, critical attention must be paid to data displays, so they

are easy to read and perform in all of these conditions.

Because there are hundreds of display manufacturers in the U.S. and thousands worldwide, identifying the right

supplier for your particular application can soon become a daunting challenge. While choosing a supplier that

meets your speci�c requirements, it is important to carefully assess your display application needs to ensure

complete and successful communication with your supplier.

For example, what kind of information will be displayed? How will environmental factors impact the design? Are

there special con�gurations that might affect your requirements, like the need to drive multiple displays from a

single device or to a need to interface with older technology? When you can communicate the precise setup in

which your display will need to operate, you will be better prepared to identify and shortlist potential suppliers.

Choosing a display partner: 5 important characteristics

14 | Volume 2 | spar tonnavex.com

CHOOSING A DISPLAY PARTNER

2 A REPUTATION FOR SUPPORTOf course, the supplier you select should be knowledgeable, responsive to tech-nical issues, and historically supportive to customers after the sale. The supplier should have a track record for working closely with customers every step of the

way to resolve issues. Ask potential suppliers about their history of customer service and what their process is when working with customers on technical issues. Ideally, you’ll want to hear that they involve their engineering team in working with customers to resolve issues.

3 UNDERSTANDING OF YOUR INDUSTRY, ISSUES, AND REQUIREMENTSAn important step in the screening process is “interviewing” potential sup-pliers to assess their level of knowledge about your industry challenges and potential requirements. Has the supplier worked with customers operating

in rugged marine or hostile industrial conditions? Do they ask the right questions about your work environment? Often, a potential supplier can help you pinpoint factors that you may not have considered that could signi�cantly affect your display con�guration.

4 LONG HISTORY IN THE DISPLAY INDUSTRYIt stands to reason that a company with a long history of supplying ruggedized display equipment to customers in your industry will be around for years to come as you require support with issues and upgrades in the future.

5 ROBUST SUPPLY CHAIN RELATIONSHIPSA potential display supplier should have good relationships with all of its com-ponent suppliers, so that they know when and where to upgrade products and can keep you informed of parts such as video boards, power supplies and LCD

panels that may be nearing obsolescence. Display suppliers that have good relation-ships with component manufacturers may even purchase end-of-life products so that

they are on hand if and when they are needed. Just as important, the supplier should have a robust counterfeit parts inspection program to prevent introduc-tion of counterfeit electronics compo-nents into the manufacturing process.

WORKING WITH YOUR SUPPLIERIdeally, your supplier takes on a role of consultant in working with you to identify your speci�c display requirements. With your supplier, it will be important to begin by developing a detailed description of your application. This will then help the supplier recommend the appropriate display.

Even when you have provided as much detail as possible, the supplier should con-tinue to probe for information, so that they can learn more about your conditions and provide you with the most accurate esti-mate possible. Questions that the supplier may ask about your requirements include:

› What grade is needed – rugged (special considerations for shock, vibration, EMI) or industrial

› Are there requirements for managed product lifecycle?

› What size display do you need? Aspect ratio? Brightness? Resolution?

› What will the mounting con�guration be?

› Is a touch screen required?› Do you have a preferred power input?

In the end, the more detail you share upfront, the more time and money you will save later.

A word about touch screen technologies: It’s important to ensure that the touch technology works well for your application. For example, in an environment with a high level of ambient sounds, the technology should not be “soft touch,” which works via sound waves through glass. Resistive touch works well internally but, when used outside, the highly re�ective screen will wash out.

Once all of your requirements are iden-ti�ed and clari�ed, the supplier should provide you with a demo that you could use to con�rm feasibility of the product for meeting your needs.

CONSIDERATIONS FOR CHOOSING TOUCH SCREENSWith more than 1,200 touch-related pat-ents in the marketplace, choosing the

Precision Sensing | Volume 2 | 15

touch technology that’s right for your applica-tion can be a real challenge. Some of the fac-tors that you and your supplier should consider when choosing a touch screen technology for your display are:

› Screen size › Noise emissions › Vibration mounting › Functionality needed › Input method (�nger, stylus, or glove) › Number of points (single, dual, or

multi-touch) › Environmental conditions

(temperature, shock) › Durability › Complexity (standard display or custom) › Regulatory restrictions › Future availability if replacement needed › Budget › Power consumption

CONCLUSIONWhen selecting a display supplier, it is important to carefully evaluate the unique requirements of your users and your environment as well as the credentials of the suppliers you’re evalu-ating. And, because it’s a complex decision, it’s important to work closely with a company that offers you a wide selection of solutions, knows your industry and its challenges, and takes its relationship with you seriously, working as a partner and solutions provider and providing engineering support. Only with that level of commitment can you be con�dent that you will get a cost-effective product that works for you now and for many years to come.

AYDIN DISPLAYS1 Riga Lane

Birdsboro, PA 19508866-367-2934

www.aydindisplays.com

About Aydin Displays: For nearly 50 years, Aydin Displays has been a leading provider of display manufacturing technology for industrial and marine applications. We work closely with our customers in providing products – or developing custom products – with the features they need for their unique requirements. We work as a partner to ensure that the end product is of the highest quality and proven for performance in the harshest environments.

THE PARTICULAR CHALLENGES OF MARINE, SHIPBOARD,

AND INDUSTRIAL APPLICATIONS

Marine and shipboard applications

In order to meet the unique needs of marine and shipboard applications, displays must perform in humid, wet, or, in some cases, completely sub-mersed conditions.

They must:

› Be readable in sunlight› Provide multiple input options› Be operable in all weather conditions› Offer touch screen options that

match your environmental needs

Other factors that may need to be considered include helm space and proper cable routing in order to ensure reliable communications in these harsh environments.

Industrial applications

The tough conditions characteristic of many of today’s factories, machinery and field equipment present a unique set of challenges to the displays that must perform in these hostile industrial environments.

The most critical of these are:

› Durability and a long life cycle› Contrast› Color› Brightness› Response time› Viewing angle› Backlight life› Shock and vibration resistance

Just as with marine and shipboard applications, displays that operate in industrial environments must be readable in sunlight, operate in a wide range of weather conditions and provide multiple mounting options, and a variety of touch screen technologies.

CHOOSING A DISPLAY PARTNER

Why rugged PCs are important in military systems

The military has long been a leader in the development of new technology. This fact is no less true in the area of electronics and computers. Today, nearly everyone relies on some form of electronic device. The military is no different and is, in fact, at the forefront of rugged computer design and development.

WHAT IS A RUGGED COMPUTER?Rugged computers are designed and engineered speci�cally to operate and perform in conditions beyond the typical office envi-ronment. These types of computers can withstand harsh environ-mental conditions such as extreme temperatures, dust, rain, and vibrations. For obvious reasons, these traits appeal to the military.

Though ruggedized systems might have more of an upfront cost, studies have been done that found the long-term costs to be lower than standard, consumer-grade computers. This is due to lower failure rates, improved productivity, among other factors.

HOW DOES A COMPUTER BECOME RUGGED?Not every application, military or otherwise, has the same demands. Therefore, not all rugged systems need be as tough as the next. For some applications, additional attachments and mountings or

casings can be sufficient. More demanding applica-tions can require further design features that might include the use of lightweight metals, sealed ports, more rigid boards with greater stability, toughened screens or displays for greater resistance, touch screen technology to eliminate keyboards and their inherent risk to the environment, and similar hard-ening and reinforcement measures.

Another important technological advancement is the advent of fanless computing. Cooling fans can quickly draw in dirt and dust and even moisture to cause catastrophic failures and/or costly interrup-tions and downtime. Newer fanless computers are engineered to dissipate heat by utilizing a light-weight rugged chassis to act as a heat sink and also provide noise free operation.

RUGGED COMPUTERS AND SWAP-CThe military’s increasing demand for smaller systems demands more from manufacturers. But Size, Weight, Power, and Cost (SWaP-C) all matter and are not going away. Manufacturers who embrace these demands and deliver on them are the most successful.

THE BENEFITS GO BEYOND THE MILITARYRugged computers clearly are a bene�t to the military. Without their development, many of the missions performed could not be carried out using the best technologies available today. Standard computer systems simply don’t measure up.

That is not to say that rugged computers are bene�cial to just the military. These systems are used increasingly by industries such as manufacturing, transportation, marine computing and naviga-tion, scienti�c research, public safety, utilities, and many more.

As is often the case, technology driven by military needs bene�ts the non-military as well. Rugged computers are increasingly smaller, lighter, more reliable, and more and more available. There is no question ruggedized computers have changed the way the military performs its mission, but there is also no ques-tion rugged computers will continue to evolve and continue to bene�t both the military and non-military user.

STEALTH.COM888-783-2584

www.stealth.com

Precision Sensing | Volume 2 | 17

RUGGED COMPUTERS

SWaP-C and why your component partner mattersFor many years, the U.S. Department of Defense (DoD) has

had strict requirements about the size, weight and power

(SWaP) of components and systems developed for military

applications. A challenging budget environment led to a

new acronym including “c” for cost, or SWaP-C. In 2012, the

DoD presented a budget that was designed to “conform

to the 2011 Budget Control Act’s requirement to reduce

Defense Department future expenditures…[even though]

we still have signi�cant gaps in modernization that will

need to be �lled in coming years.”

INTEGRATING TECHNOLOGY OF THE SMALLThe 21st century military is operating on a new battle�eld, one on which soldiers are working with both legacy vehicles and air-craft and new devices with advanced capabilities. Keeping sol-diers connected to real-time logistical information and keeping devices powered up is critical, yet the need to provide device and system portability is greater than ever.

Recent advances in micro-electromechanical systems (MEMS) are delivering critical performance capabilities with signi�cant reductions in size, weight, power, and cost helping manufac-turers meet the SWaP-C challenge. Now, it’s possible for up to two or three power-hungry components to be replaced by a single component that is smaller and lighter and provides the same functionality. By working with a component partner that keeps their eyes on the big picture with out-of-the-box thinking, combining functions and sharing components, manufacturers and their military customers can reduce the number of sensors needed in a communications system.

SWaP-C challenges Many of today’s military applications require significantly advanced functionality and greater processing performance. Smaller, less costly navigation systems aren’t always as accu-rate as legacy systems and compromises and tradeoffs may be required along the way. As technology advances, soldiers carry more batteries to keep devices powered, creating a need to keep

the devices themselves as small as possible. Because legacy vehicles and systems are limited as to how much power they can provide, there is a need to integrate new technology into these systems for more power and performance with the additional challenge of limiting added weight.

All of these demands pose a challenge when the goal is to pro-vide the smallest and lightest device possible with the longest possible �eld life. As a result, product designers must often choose between power and performance at critical points in their design process. With the many challenges involved in meeting DOD demands for reductions in size, weight, power and cost, a high level of collaboration with manufacturing partners is needed.

CHOOSING THE RIGHT PARTNER

Following are some important characteristics to

seek out when evaluating a potential component

manufacturing partner.

18 | Volume 2 | spar tonnavex.com

SWAP-CSWAP-C

1 FLEXIBILITYYour partner should work with you to develop a truly col-laborative relationship and be willing to go beyond simply delivering the device; they should also collaborate every

step of the way to help reduce the SWaP-C of the �nished product. A good partner understands the criticality of each component of SWaP-C reduction guidelines and will work diligently to help make adjustments in the overall device or system. Even if the partner cannot make direct reductions in the size or weight of the speci�c component, their software engineers may be able to make �rm-ware adjustments or make tradeoffs between components that will result in signi�cant cost savings down the line.

2 OUT-OF-THE BOX THINKING The ideal partner will bring a combination of engi-neering experience and innovative thinking to the end product. It will be important to seek out a partner that

sees the “big picture” to �nd creative solutions that can not only reduce the size and weight of the �nished product, but also incorporate technologies that can actually multitask and replace more than one component.

It is also important to keep an eye out for innovations that the partner is developing that may bene�t future designs. Many com-ponent manufacturers are working on new technologies that are potential game changers. Watch and listen for hints at designs in development that could make a difference in the future.

3 ONGOING SUPPORT It is important to work with a partner that plays a consul-tative role throughout the design and development pro-cess. By engaging a partner early in the process, they

are better able to collaborate on adjustments that can be made to the device when needed and help get the end product back on course.

4 MILITARY KNOW-HOW New components or designs for aerospace and defense must undergo a rigorous quali�cation process and require a signi�cant amount of internal testing and review. A

partner that has an understanding about how the military works can provide technical support and adjustments quickly at critical points in the process. As a result, it is important to work with a company that has a history of working with the military and is familiar with how the military does business.

5 FORWARD THINKING Chances are, when the time comes for the next genera-tion of a device, the military will set new requirements for lighter weight, better performance and more capa-

bilities – at the same cost or less. That is why a partner should

Precision Sensing | Volume 2 | 19

always be looking for ways to decrease the weight and cost – and increase the performance – of the component so that the next product upgrade can quickly meet new requirements.

CONCLUSIONWhile recent technological advances are helping the military and their manufacturing partners meet the demand for reductions in size, weight, power, and cost will continue to be a daunting chal-lenge, and it will continue to be important to work with a partner that goes beyond the product to provide a complete package of solutions, service, and support.

Rugged, mission-critical military and aerospace applications need the design and manufacturing sophistication of a partner such as Sparton. As both a defense contractor and a supplier to recognized leaders in the market, we have expertise in your demanding and highly regulated environment.

We create devices that include a variety of highly specialized technologies such as embedded systems, RF, lasers, optics, sensors and robotics for uses as varied as undersea war-fare to cockpit controls and satellite communications. Every project we take on benefits from the Sparton Production System, as well as our experience and commitment to building strong partnerships.

About Sparton Navigation and Exploration: Sparton Navigation and Exploration has more than a century of experience designing and building for governments and industries worldwide, including systems such as our inertial systems and advanced acoustic hydrophone.

For the last 70 years, we’ve been the only company to integrate both navigation and acoustic sensor technology, resulting in the production of over six million of the most advanced sonobuoys for the world’s navies.

Today, we continue to add capabilities and technology that allow us to offer more solutions than ever for your challenges. Our knowledgeable and highly experienced engineering team is always available to help you integrate our sensor solutions into your applications. For more information, visit www.spartonnavex.com.

SPARTON NAVIGATION AND EXPLORATION5612 Johnson Lake Road

De Leon Springs, FL 32130 800.824.0682

www.spartonnavex.com

20 | Volume 2 | spar tonnavex.com

SWAP-C

Compass terminology

There is so much terminology when talking about navigation products that it can be confusing. What is an Attitude Heading Reference System (AHRS) and how does it differ from a Dead Reckoning (DR) module? Some prod-ucts have GPS integrated and others don’t. So let’s go over the basics of these terms and see what they all mean.

DIGITAL (MAGNETIC) COMPASS › This is the most basic compass product. It usually contains tri-axial

magnetometers and accelerometers and provides a measurement of orientation (or attitude). Output is usually heading, pitch, and roll. These devices are intended for stationary or low-dynamic application.

GYRO-ENHANCED (OR GYRO-STABILIZED) COMPASS › This is similar to the digital compass but also contain tri-axial

gyroscopic sensors (also known as angular rate sensors). These devices also provide a measurement of orientation/attitude and output heading, pitch, and roll. They are intended for stationary to high-dynamic applications. Accuracy over temperature is typically less than what is available in an AHRS device.

ATTITUDE HEADING REFERENCE SYSTEM (AHRS) › These devices are very similar to the Gyro-Enhanced compasses

but are fully characterized over temperature. These devices are used for accurate orientation (heading, pitch, and roll) over a wide range of dynamic and thermal conditions. They tend to be more expensive due to the higher level of thermal calibration required.

DEAD RECKONING (DR) OR INERTIAL NAVIGATION SYSTEM (INS) › These devices combine accurate orientation (like an

AHRS module) with a navigation algorithm. The navigation algorithm integrates the tri-axial accelerometers to estimate position and velocity in 3-dimensions. Keep in mind that measurement noise will always cause errors to be integrated into the position and velocity estimates. These errors will grow unbounded over time and will need to be corrected periodically with a known position or set to zero for relative navigation.

GPS-AIDED INERTIAL NAVIGATION SYSTEM (GPS/INS) › GPS refers to the satellite-based Global Positioning

System that has become so frequently used today. GPS gives a direct measurement of position on the Earth. By using this information within an inertial navigation system, the module can periodically correct its location and minimize the integration errors in the position and velocity estimates. In some situations, the GPS signal can become blocked (GPS denied environment). In these situations, the GPS/INS module performs dead reckoning until the GPS signal is reacquired.

Precision Sensing | Volume 2 | 21

MILITARY COMPASS

What’s wrong with this compass: and how errors can be mitigatedIf you have ever dealt with a magnetic compass before, you might have heard of in-�eld calibration. Many don’t realize just how important this user calibration is to achieving precision heading accuracy. A basic digital compass is composed of tri-axial mag-netometers and accelerometers. Magnetometers are sensitive to the Earth’s magnetic �eld and accelerometers are sensitive to the Earth’s gravitational �eld. To determine a magnetic heading, we want to measure the direction of north in the horizontal plane that is level to our local geographic location. If we don’t hold the compass level, we would then need to measure its orientation relative to the direction of gravity and then mathematically rotate the magnetometers to determine a magnetic heading. You can see how these two sensors need to work together to obtain an accu-rate orientation. Let’s take a brief look at what errors can impact compass accuracy and what can be done to mitigate those errors.

INTRINSIC ERRORSIntrinsic errors are inherent within the compass. These consist of errors associated with the sensors themselves or how they are aligned during assembly. These types of errors exist during production and can usually be mitigated within the design or addressed through a precision factory calibration.

Some intrinsic errors associated with both magnetometers and accelerometers are:

› Misalignment of sensors (Orthogonality) › Different sensitivity between the tri-axial (XYZ) sensors › Non-linearity of sensors › Sensor offsets › Temperature instability

EXTRINSIC ERRORSExtrinsic errors are external to the compass and are caused by external effects that may be local to the compass (within the embedded application) or external to the application all together (buildings or bridges).

Some extrinsic errors are:

› Compass alignment to user’s device › External Magnetization that adds to Earth’s magnetic �eld › Non-Uniform magnetic �eld due to nearby magnetic

material (gradient �eld) › Magnetic �eld generated by electric current in wires

(AC or DC) › Fast rotations of compass causes skewing in sensor

measurements › Vibration or acceleration due to movement

MITIGATION OF COMPASS ERRORSMost intrinsic errors are handled by either addressing potential problems during the design phase or by performing a calibration of the compass during production. Temperature instability should be considered during the design phase to select parts that are inherently stable over the intended operating range. Any residual errors can be minimized in the factory calibration. Magnetometer and accelerometer alignment, sensitivity, and non-linearity are easily addressed during factory calibration.

Extrinsic errors are handled in different ways. Boresight (rota-tion) matrix handles the Alignment of the compass to the user’s application. Most magnetic effects associated with the embedded application can be addressed by having the user perform an in-�eld calibration of the magnetometers. Sparton has developed an innovative adaptive algorithm that adjusts the magnetometer offsets and sensitivities to provide the end user with optimal performance for their particular application. Any transient noise can be handled by �ltering the sensor data within the compass. Many compasses allow the user to set some level of digital �ltering. Too much �ltering will cause the compass to appear sluggish or slow to react during fast rota-tions. This can be overcome by augmenting the compass with gyroscopes (angular rate sensors).

A compass containing gyroscopes will always be more responsive to rotations than a compass based on magnetom-eters and accelerometers alone. It also has the added bene�t of maintaining compass accuracy when the magnetometer, accelerometers, or both are completely unreliable due to momentary extrinsic errors mentioned above. They also gen-erally require a faster sample rate of the sensors to mitigate the slewing errors caused by fast rotations. Gyro-stabilized compasses tend to be more expensive due to the additional factory calibration required but may be worth it if your applica-tion requires higher performance.

Many errors, both intrinsic and extrinsic, can affect compass accuracy. All Sparton products undergo a precision, computer-controlled factory calibration, as well as providing a means for in-�eld calibration (boresight alignment matrix, adaptive mag-netic calibration, digital �ltering, and optional gyroscopes). Once the compass is installed in the embedded application, it must learn what the surrounding distortions and alignment errors are in order to provide accurate orientations. To do this requires assistance from you, the end-user. By understanding the errors that affect magnetic compasses and how to mitigate them, you can greatly improve the success of your integration efforts.

22 | Volume 2 | spar tonnavex.com

MILITARY COMPASS

VIDEOS

Precision Sensing | Volume 2 | 23

VIDEOS

SPARTON NAVEX PRODUCT OVERVIEW This short introduction video to see the precision inertial sensors offered by Sparton NavEx and some of their many potential applications.

AHRS-8 QUADCOPTER DEMONSTRATION The Sparton AHRS-8 inertial sensor system compensates for magnetic interference in a magnetically challenged environment.

IMU-10 INERTIAL MEASUREMENT UNIT In this video we discuss our Inertial Measurement Unit, the Sparton IMU-10. The IMU-10 is our ultimate sensing system, featuring 10 Degrees of Freedom and High Speed Synchronous sampling. For more information visit us at www.SpartonNavEx.com. Music by Mike Bagley & Harry Newhook, “Avarice.”

AN INTRODUCTION TO SPARTON NAVEX An introduction to who we are and what we do – our prod-ucts, features, and what sets us apart as your solution partner. Visit us SpartonNavEx.com to learn more.

Laser Targeting

In situations where precision is an absolute must, Sparton delivers the inertial sensor systems that can be trusted time and time again. Our products have been built to improve on today’s product standards with even greater performance than is required for tomorrow’s laser targeting systems.

Targeting systems require maximum accuracy at all times and under all conditions. Whether hand-held or mounted on tri-pods, vehicles, or weapons the system must perform reliably and con-sistently to meet the needs of today’s war�ghter.

Heading and azimuth angle are vital components for accurate targeting. The complex nature of targeting systems presents signi�cant challenges to obtaining maximum accuracy reliably, quickly, and repeatedly. Magnetic disturbances, whether pro-duced by external sources or internal components of the system, cause errors in the output of conventional digital magnetic com-passes (DMCs).

A complete system integrating MEMS inertial sensors, magne-tometers, and algorithms to process and manage sensor data is required to overcome the difficulties of this complex application. All this must be accomplished in a small, lightweight package with minimum power consumption.

Unmanned Systems

Unmanned vehicles continue to impress with rapid advances in technology that make these vehicles suitable for military and commercial use. The inertial sensor is a critical component for unmanned operation success and Sparton is lock step in the rapid development of sensor systems technologies for air, sea, and ground.

Whether it swims, crawls, or �ies navigation systems are critical for performance of unmanned vehicles. These systems sup-port complex functions such as surveillance, reconnaissance, vehicle tracking, hazardous material disposal, and many military/defense applications. In harsh environments or when GPS is not available (denied or comprised) it is vital to maintain accurate heading and orientation of the unmanned vehicle.

Conventional navigation solutions take up large amounts of space, are costly, heavy, and have high power consumption. Transient magnetic disturbances can induce heading errors compromising performance.

Applications requiring the highest degree of precision trust Sparton as their go-to solution for inertial

sensor systems. The entire product family, from inertial measurement units (IMU) to attitude heading

reference systems (AHRS), performs to task for the toughest, most ruggedized solutions. Stemming from

our roots in government contracting, the Sparton suite of products are unmatched for critical solutions

such as laser targeting, satellite communications, unmanned vehicles, and oil and gas exploration.

SOLUTIONS

Learn More �

Learn More �

24 | Volume 2 | spar tonnavex.com

SOLUTIONS

Communications Positioning

Panning the sky in search for satellite signals takes on a whole new meaning in urgent conditions when time is of the essence. Getting your connections established in short order requires absolute accuracy – accuracy that can only be delivered by Sparton’s inertial sensor systems.

Whether your product is intended to be used in defense or civilian applications, the performance of today’s leading edge communication systems are demanding efficient, reliable and accurate antenna positioning. In either portable or permanent system installations, RF and SATCOM systems require high antenna pointing accuracy at all times and under extreme envi-ronmental conditions.

Azimuth and elevation angles are vital components for accu-rate antenna positioning and optimum system performance. The complex nature of communication systems presents signi�cant challenges to obtaining maximum accuracy- reliably, quickly, and repeatedly. Manual antenna pointing and alignment can be cum-bersome and time consuming for your customer. Since most sys-tems measure the Earth’s horizontal magnetic �eld to determine heading, unwanted magnetic disturbances, whether intrinsically produced by hard and soft iron components on the antenna plat-form, or from transient external sources cause errors in the heading output of conventional analog or digital magnetic compasses.

A complete system integrating MEMS inertial sensors, mag-netometers, and algorithms to process and manage sensor data is required to overcome the difficulties of this challenging application. For many applications this must be accomplished cost effectively within a small, lightweight package with minimal power demands on the system.

Exploration and Surveying

Exploring the vast ocean �oor for oil and gas opportunities is a daunting task. Sparton’s inertial sensor product offerings help produce the critical accuracy needed to survey, collect, and ana-lyze the sea �oor to mine these natural resources.

The performance of today’s leading edge towed seismic streamer systems and bottom mounted arrays are demanding more efficient, reliable, and accurate cable navigation and posi-tioning. In seismic system installations, these systems require high heading and attitude accuracy real-time and under extreme ocean conditions.

Precise and real-time measurements of heading, pitch, and roll angles along the array cables are valuable output data for accurate seismic streamer navigation, positioning and survey performance. The complex nature of dynamic seismic sub-bottom profiling and imaging systems presents significant technical challenges, requiring maximum sensor accuracy - reliably, quickly, and repeatedly. Seismic data collection is costly and time consuming. Oil and gas geophysical explo-ration customers are increasing demands for better survey data quality.

A complete system integrating MEMS inertial sensors, mag-netometers, and algorithms to process and manage sensor data is required to overcome this challenging application. More accurate streamer positioning and navigation results in enhanced, higher resolution image processing from the ship’s survey. For seismic streamers and in-water ancillary equip-ment this must be accomplished cost effectively within a small, lightweight package with minimal power demands on the data acquisition system.

Learn More � Learn More �

Precision Sensing | Volume 2 | 25

Fully temperature compensated, the AHRS-8 is individually calibrated for industry-leading heading accuracy. Our AdaptNav II™ algorithm provides accurate in-�eld calibration, while the NorthTek™ Development System makes it the world’s only fully programmable inertial system.

› Integrated AdaptNav II™ provides real-time noise characterization and active gyro drift compensation for superior heading, pitch and roll performance in electrically and mechanically noisy environments

› Fully temperature compensated over the entire operating range, individually calibrated from -40° to +70° C

› Powerful user programmable sensor customization apps via NorthTek™ Forth interpreter

› 2-D and 3-D adaptive in-�eld cal providing hard and soft magnetic interference compensation

› Advanced sensing technology (3-axis magnetic, 3-axis MEMS acceleration, and 3-axis MEMS gyro)

› Selectable 4g or 8g accelerometer ranges, suitable for highly dynamic application environments

› Magnetic and True North heading (yaw), pitch, and roll measurement

› Full 360° rollover capability› Low power consumption and power management (Sleep

Mode) functionality› Supports multiple communication protocols› In-�eld calibration point selection and distribution indicator› Quality of in-�eld calibration indicator› Centripetal acceleration correction

Harsh environmental conditions, extreme magnetic interference, mechanical shock and transient platform vibrations all contribute to the challenge of high accuracy inertial sensing and platform attitude reporting. Sparton’s IMU-10 inertial sensing system thrives in such environments and provides end-users with a reli-able high-performance, high-accuracy 10DOF inertial sensing package in a ruggedized enclosure.

› 10DOF High Performance Inertial Measurement Unit (IMU)› Advanced Micro Electro-Mechanical (MEMS) sensing

technology (3-axis magnetic, 3-axis acceleration, 3-axis gyro and Barometer)

› 40 kHz accel/gyro (all simultaneous) data sampling �ltered to 2 kHz

› Coning/sculling compensation of 2 kHz data down to customer de�ned rate

› Customizable on-board high speed digital �ltering› High Speed UART interface (user selectable up to 1MBaud)› High speed data logging capability to off-board µSD card› Ruggedized, shockproof design with proprietary seals that

allow barometric pressure sensing combined with IP67 performance

› Low latency and consistent latency between data collection and data output

› Powerful user programmable customizations via NorthTek™

Forth interpreter› Supports multiple communication protocols› Full 360° rollover capability

AHRS-8 IMU-10

26 | Volume 2 | spar tonnavex.com

PRODUCTS

PRODUCTS

A small, rugged, omnidirectional, broadband hydrophone designed for high-quality performance and real-world durability, it exhibits minimal change in response and directivity with tem-perature and hydrostatic pressure, and interfaces easily with any signal analyzer or data recording system.

› Flat broadband frequency response› Omnidirectional› Low power› Low noise› Built-in calibration› Rugged› 10m cable

Typical Applications

› Marine mammal monitoring › Marine seismic acquisition › Acoustic arrays › UUVs › Underwater communications › Source level monitoring › Environmental monitoring › General purpose research › Fisheries research › Industrial measurements

Incorporating next generation software to enable optimized performance, the DC-4E with 6 DOF offers improved in-�eld calibration and reduced start-up time. Its best-in-class reliability and accuracy provides 3-D absolute magnetic �eld measure-ment and full 360° tilt-compensated heading, pitch, and roll data.10DOF High Performance Inertial Measurement Unit (IMU)

› 2-D and 3-D adaptive in-�eld calibration providing hard and soft magnetic interference compensation

› Simple 2-wire serial (UART) interface (3.3V logic level) with user-selectable baud rate

› Built-in World Magnetic Model for accurate True North› Advanced sensing technology (3-axis magnetic, 3-axis

MEMS acceleration)› Magnetic and True North heading (yaw), pitch, and roll

measurement› Low power consumption and power management (Sleep

Mode) functionality› Powerful user programmable customizations via NorthTek™

Forth interpreter› Industry leading static accuracy and resolution› Rugged (epoxy encapsulated) construction› Supports multiple communication protocols› Full 360° roll-over capability› Small physical size› In-�eld calibration point selection and distribution indicator› Quality of in-�eld calibration indicator

PHOD-1 DC-4E

Precision Sensing | Volume 2 | 27

Sparton Navigation and Exploration 5612 Johnson Lake Road P.O. Box 788 DeLeon Springs, Florida 32130

spartonnavex.com

© 2016 Sparton Navigation and Exploration