Total Lightning Detection

Total Lightning DetectionTotal Lightning DetectionYour Name& Affiliation

Why Use Lightning Information?Why Use Lightning Information?• Lightning data is real-time, no delays!

• Lightning assists in routing aircraft around storms.

• It is absolutely necessary for safety during ground operations--refueling and other aircraft preparations.

• Lightning is a valuable meteorological data source that enhances other sources such as weather radar.

• Lightning information covers a large area, even extending out to the ocean.

• Lightning information is very economical.

• Lightning data is real-time, no delays!

• Lightning assists in routing aircraft around storms.

• It is absolutely necessary for safety during ground operations--refueling and other aircraft preparations.

• Lightning is a valuable meteorological data source that enhances other sources such as weather radar.

• Lightning information covers a large area, even extending out to the ocean.

• Lightning information is very economical.

AFWA’s Current NLDN Lightning Data Stream

• Cloud-to-ground (CG) data only• But…a large percentage of lightning occurs in cloud

(IC)• IC often precedes CG by 5-20 min• Research shows IC + CG is better indicator

of storm severity than CG alone• IC + CG is now available at reasonable price

You Don’t Want This to HappenYou Don’t Want This to Happen

Three Lightning Detection Technologies

Three Lightning Detection Technologies

VLF reflected betweenground and ionosphere(long-range network)

LF/VLF ground wave(NLDN) VHF line-of-sight only

(SAFIR, LDAR II, LS8000)

CG Lightning Detection--LF CG Lightning Detection--LF • C-G lightning typically detected in the LF range.

– Longer detection range.– Ability to locate ground strike point with high

accuracy.– Ability to determine lightning polarity and peak

current.– Some ability to differentiate between C-G and cloud

lightning.• C-G lightning has a fingerprint detected in its waveform.• C-G lightning is located using one of these methods.

Time of Arrival (TOA) Magnetic Direction Finding (MDF)

• C-G lightning typically detected in the LF range.– Longer detection range.– Ability to locate ground strike point with high

accuracy.– Ability to determine lightning polarity and peak

current.– Some ability to differentiate between C-G and cloud

lightning.• C-G lightning has a fingerprint detected in its waveform.• C-G lightning is located using one of these methods.

Time of Arrival (TOA) Magnetic Direction Finding (MDF)

Total Lightning (IC+CG) Detection-VHF Total Lightning (IC+CG) Detection-VHF

LMA – New Mexico Tech (VHF TOA)LDAR-II Vaisala (VHF TOA) – Not on the marketLS 8000 Vaisala Interferometry SystemWTLN WeatherBug (Broadband TOA system)

LDAR-II & LMA TOA Systems Small areal coverage Large number of sensors required 3-D displays are good But…Too expensive---few networks exist

VHF Interferometry---a Timing Measurement Technique

VHF Interferometry---a Timing Measurement Technique

• The two most common methods of locating lightning in the VHF range are Time-of-Arrival and Interferometry.

• Interferometry consists of measuring the time difference between closely spaced antennas. The main difference with Time-of-Arrival is that it operates on continuous waves and not individual pulses.

• The accuracy is achieved by integrating a very large number of periods (typically 11 000 for each measurement)

• The two most common methods of locating lightning in the VHF range are Time-of-Arrival and Interferometry.

• Interferometry consists of measuring the time difference between closely spaced antennas. The main difference with Time-of-Arrival is that it operates on continuous waves and not individual pulses.

• The accuracy is achieved by integrating a very large number of periods (typically 11 000 for each measurement)

T.O.A. Interferometry

dT d~100µs ~9nsd d d

The Vaisala LS Series Lightning Detection System

CG + IC = Total Lightning

The Vaisala LS Series Lightning Detection System

CG + IC = Total Lightning

LS8000 Sensor – Total Lightning Detection

LS8000 Sensor – Total Lightning Detection

• Technology: – VHF Interferometry combined with LF Time

of Arrival (TOA) and Magnetic Direction Finding (MDF)

– VHF for 2-D cloud lightning mapping– LF for accurate CG detection (as in NLDN)

• Benefits:– Longer baseline network (fewer sensors) to

cover same area as VHF-TOA (LDAR II)– Accurate LF CG data, improvements to 250

meter Location Accuracy– Lower overall cost of ownership

• Technology: – VHF Interferometry combined with LF Time

of Arrival (TOA) and Magnetic Direction Finding (MDF)

– VHF for 2-D cloud lightning mapping– LF for accurate CG detection (as in NLDN)

• Benefits:– Longer baseline network (fewer sensors) to

cover same area as VHF-TOA (LDAR II)– Accurate LF CG data, improvements to 250

meter Location Accuracy– Lower overall cost of ownership

• The 5 dipole antenna VHF interferometry system locates cloud discharges with a high level of accuracy

• The LF antenna from the gives detailed CG information

• Combining the two gives a clear picture of total lightning and mapping the full spatial extent of flashes

• The 5 dipole antenna VHF interferometry system locates cloud discharges with a high level of accuracy

• The LF antenna from the gives detailed CG information

• Combining the two gives a clear picture of total lightning and mapping the full spatial extent of flashes

The LS8000 Sensor The LS8000 Sensor

● Interferometry allows longer baselines between sensors (larger areal coverage) and increased

accuracy compared to other VHF total lightning systems.

● Proper sensor siting is critical…must have clean horizon.

● Cloud must have active discharges to be detected.

● The LS8000 is not a 3-D system…only 2-D.

● Interferometry allows longer baselines between sensors (larger areal coverage) and increased

accuracy compared to other VHF total lightning systems.

● Proper sensor siting is critical…must have clean horizon.

● Cloud must have active discharges to be detected.

● The LS8000 is not a 3-D system…only 2-D.

Notes

Examples of Using Total Lightning Data

You See Paths of All FlashesYou See Paths of All Flashes

– Detects over 90% of all cloud lightning and CG lightning

– Maps the spatial extent of both cloud and the in-cloud portion of CG flashes

– Detects over 90% of all cloud lightning and CG lightning

– Maps the spatial extent of both cloud and the in-cloud portion of CG flashes

Start

End

Some Cloud Flashes are Very Long

Some Cloud Flashes are Very Long

• 13 October 2001

North Texas

• Cloud flash was ~190 km long (from ~ Waco to Dallas, TX).

• It put down two CG flashes along the way

(white symbols)

• 13 October 2001

North Texas

• Cloud flash was ~190 km long (from ~ Waco to Dallas, TX).

• It put down two CG flashes along the way

(white symbols)

Quiz--Where is Lightning Threat?Not just where CG is occurring

Quiz--Where is Lightning Threat?Not just where CG is occurring

IC (red) and CG flashes (black) between 0312:30 - 0317:30 UTC

15 June 2001

IC (red) and CG flashes (black) between 0312:30 - 0317:30 UTC

15 June 2001

Fort Worth WSR-88D base reflectivity from 0315 UTC 15

June 2001

Fort Worth WSR-88D base reflectivity from 0315 UTC 15

June 2001

High CG Lightning Threat

Isolated CG Lightning Threat

High CG Lightning Threat

IC flashes cover much larger area than CG flashes—the threat area is much larger than where CG occurs.

ImminentCG threat?

Can radar alone provide sufficient information to assess lightning data?

Can radar alone provide sufficient information to assess lightning data?

24 April 200824 April 2008

Does the KDFW boxhave a lightningthreat ?

No!! Note VHF total lightning perspectiveNo!! Note VHF total lightning perspective

24 April 200824 April 2008

IC lightning already occurring

Total lightning perspectiveTotal lightning perspective

24 April 200824 April 2008

3 CG flashes on edge of box—far away from mainlightning region

Example 2 – Radar PerspectiveDo both boxes have a lightning threat?Example 2 – Radar PerspectiveDo both boxes have a lightning threat?

07 - 08 UTC 6 November 2006 movie07 - 08 UTC 6 November 2006 movie

NLDN CG Lightning PerspectiveNLDN CG Lightning Perspective

07 - 08 UTC 6 November 200607 - 08 UTC 6 November 2006

CG but no dBZ

VHF Total Lightning PerspectiveVHF Total Lightning Perspective

07 - 08 UTC 6 November 2006 movie07 - 08 UTC 6 November 2006 movie

IC but no dBZ

Example 3Example 3Go to animation! Tucson Total Lightning NetworkGo to animation! Tucson Total Lightning Network

July 26, 2008July 26, 2008

Example 3Example 3Go to animation! Tucson Total Lightning NetworkGo to animation! Tucson Total Lightning Network

July 26, 2008July 26, 2008

Tucson LS8000 NetworkIC precedes CG & IC threat persists in CG lull

Tucson LS8000 NetworkIC precedes CG & IC threat persists in CG lull

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0:34 0:40 0:46 0:52 0:58 1:04 1:10 1:16 1:22 1:28 1:34 1:40 1:46 1:52 1:58 2:04 2:10 2:16

Time UTC

3-m

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Cloud flashes

CG strokes

HailHail WindWind

Cloud flash precede CG strokesCloud flash and CG stroke rates for a severe thunderstorm11 August 2007

Identification of turbulence

within thunderstorm

anvils

Identification of turbulence

within thunderstorm

cores

Only LS8000 can identify anvil regions

Aviation Applications, Turbulence IdentificationAviation Applications, Turbulence Identification

Building a Total Lightning Network

Building a Total Lightning Network

1 – Vaisala Thunderstorm Sensor1 – Vaisala Thunderstorm Sensor

3 – Real-time Displays3 – Real-time Displays

2 – TLP™central processor2 – TLP™central processor

The Lightning Detection Network

The Lightning Detection Network

Building an LS8000 NetworkBuilding an LS8000 Network• Sites must be carefully selected:

– Distance between sensors: 100 to 150 km for an Interferometric network

– Sensors should be in “Triangle strips”

– Each sensor should have an optimal Field of View---No far obstacles

– Antenna surroundings should be as clean as possible---No close obstacles

– Sites should be free of strong radio sources

– Noise floor should be as low as possible

– Power and communication should be easily available

– Site should be accessible (installation and maintenance)

• Sites must be carefully selected:

– Distance between sensors: 100 to 150 km for an Interferometric network

– Sensors should be in “Triangle strips”

– Each sensor should have an optimal Field of View---No far obstacles

– Antenna surroundings should be as clean as possible---No close obstacles

– Sites should be free of strong radio sources

– Noise floor should be as low as possible

– Power and communication should be easily available

– Site should be accessible (installation and maintenance)

Building a VHF NetworkBuilding a VHF Network

• Interferometric Network

• Location Accuracy for a full network of sensors, about 100 km apart.

• Interferometric Network

• Location Accuracy for a full network of sensors, about 100 km apart.

Location accuracy is better than 1 km almost everywhere

What Displays Would You Have ?

Total Lightning Display – Flash Extent Density (FED)

Total Lightning Display – CLD FED map with CG overlay

Total Lightning Display – CLD flash map with CG overlay

Have Multiple Windows

Nowcast Storm Movement

Visual, Audible, and E-mail Warnings

The Proposed Northwest Florida Total Lightning Network

The Proposed Northwest Florida Total Lightning Network

VHF Site Projections Cloud Flash DE %

VHF Site Projections Cloud Flash DE %

7 sensors at:

1. ABY

2. OZR

3. EVX

4. AQQ

5. VAD

6. CTY

7. TLH

7 sensors at:

1. ABY

2. OZR

3. EVX

4. AQQ

5. VAD

6. CTY

7. TLH

> 90%

Benning

Tyndall

MoodyRucker

Hurlburt

Six military installations receive excellentcoverage with this network

CG Flash Detection Efficiency %

> 90% in

all 6 military areas

Hurlburt

Rucker

Moody

Benning

Tyndall

CG Stroke Location Accuracy (km)

• < 0.5 km over land

Collaborations

• Florida State University has been researching the operational use of lightning data for many years.

• They would like to receive the data and work with us to use the data to maximum advantage.

• This would involve visits, seminars, etc. to DOD facilities.

Northwest Florida Total Lightning Network

The Cost

Northwest Florida Total Lightning Network

The Cost

Vaisala LS8000 Total Lightning Network Cost Estimates

• A network of 7 LS8000 Sensors

• LTS viewing software and hardware

• Includes sensor installations, masts, and communications equipment and fees

• Hardware and software located at: HRT; AQQ; CTY; OZR; ABY; TLH; VAD

• Scenario 1: Government owned network / Vaisala managed– USAF purchases:

• The 7 LS8000 sensors and required mounting hardware• LTS viewing software and hardware• ~$716K for Vaisala equipment (one time charge) • USAF responsible for civil works and sensor maintenance / repair

– Vaisala will provide:• Communications equipment• Installation of all equipment and sensors• Training on LS8000 sensors and LTS viewing software• Annual 24/7 network data processing with TLP processor, monitoring, quality

control of data, data archiving, and be responsible for communications.• Make this data available to each of the locations via TCP/IP • ~$220K annual fee

– Total cost year one: $936K / Year two ~$220K

Cost Estimates

Cost Estimates

• Scenario 2: Vaisala owned and operated network– Total ‘turn key’. Vaisala will conduct site surveys, complete

civil works, install 7 LS8000 sensors, communications equipment, 7 LTS viewing software displays with hardware, train operators on the use of LTS and be responsible for all aspects of 24/7 monitoring, quality control reporting, data archiving, and up time reports.

– Vaisala will make this data available to each of the locations. – Annual fee: ~$515K/yr

Questions