Satellites for Beginners

7/31/2019 Satellites for Beginners

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Satellites for Beginners

Overview of SatellitesTypes of Orbits

Orbital MechanicsKeplerian ElementsSatellite Tracking

Antenna BasicsSimple Transmitters/ReceiversSatellites for Beginners


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Types of Orbits


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Types of Orbits

Low Earth Orbit290 1,600 kms

Medium Earth Orbit10,000 16,000 kms

Geosynchronous Orbit36000 kms


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Orbital Mechanics


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Orbital Mechanics


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Orbital Mechanics


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Orbital Mechanics


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Keplerian ElementsCATALOG NUMBER EPOCH TIMEELEMENT SET NUMBER

INCLINATIONRAANECCENTRICITYARGUMENT OF PERIGEEMEAN MOTIONORBIT NUMBER CHECKSUM


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Keplerian ElementsNASA 2 Line format

AO-071 07530U 74089B 04197.68802813 -.00000029 00000-0 10000-3 0 29552 07530 101.6797 243.9770 0012017 165.7959 194.3449 12.53568878357487

AMSAT FORMATSatellite: AO-07Catalog number: 07530Epoch time: 04197.68802813Element set: 295Inclination: 101.6797 degRA of node: 243.9770 degEccentricity: 0.0012017

Arg of perigee: 165.7959 degMean anomaly: 194.3449 degMean motion: 12.53568878 rev/dayDecay rate: -2.9e-07 rev/day^2Epoch rev: 35748Checksum: 348


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Satellite Tracking Manual tracking of Satellites


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Satellite Tracking Computer Tracking


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Satellite Tracking Globe view


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Antenna Basics

Directional propertiesTransmitting vs. Receiving properties

EfficiencyPolarizationIsotropic Antenna


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Antenna Basics Antennas not for beginners.


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Antenna Basics Antennas for Beginners


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Antenna Basics

Vertical-plane gain patternsShowing the relative fieldintensity for half-wavedipole above perfectly

Conducting ground.Pattern at right angles todipole. (A) is for heightof wavelength,(B) Is for height 3/8wavelength, and

(C) is for height of 1.5wavelengths.


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Antenna Basics


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Antenna Basics


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Antenna Basics


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Simple Transmitters/Receivers VERY BASIC LIST: VHF/UHF FM transceiver/handheld transceiver.

VHF/UHF wave antenna.

2.5 W for the hand held.

INTERMEDIATE LIST VHF/UHF Multimode. VHF/UHF beam antennas. Azimuth & Elevation control

rotator.Higher power for the ellipticalorbit satellites.


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Satellites for BeginnersINTERNATIONAL SPACE STATION (ISS) - ARISSCatalog number: 25544Launch date: November 20, 1998

Status: OperationalDigipeater: Active

The current Expedition 12 crew is:

Commander: William McArthur KC5ACRFlight Engineer: Valery Tokarev (no call)

Worldwide packet uplink: 145.990 MHz FMRegion 1 voice uplink: 145.200 MHz FMWorldwide downlink: 145.800 MHz FM

Russian callsigns RS0ISS, RZ3DZRUSA callsign NA1SSPacket station mailbox callsign RS0ISS-11Packet station keyboard callsign RS0ISS-3Digipeater callsign ARISS


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Satellites for BeginnersFO-29 JAS-2Catalog number: 24278Launch Date: August 17, 1996

Status: Operational

Voice/CW Mode JAUplink: 145.90 to 146.00 MHz CW/LSBDownlink: 435.80 to 435.90 MHz CW/USBBeacon: 435.795 MHz

Digital Mode JDUplink: 145.850 145.870 145.910 MHz FMDownlink: 435.910 MHz 1200-baud BPSK or 9600-baud FSKCallsign: 8J1JCSDigitalker: 435.910 MHz

Please send the reception reports to [email protected] . Please use thesubjectline: 'FO-29reception report'.


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Satellites for BeginnersCatalog number: 28375Launch date: June 29, 2004

Status: Operational

FM Repeater, V/UUplink: 145.920 mhz FM, 67 hz PL ToneDownlink 435.300 mhz FM9k6 Digital, V/U, PBP BBS (Pacsat Broadcast Protocol BBS)TLM Data ActiveUplink: 145.860 mhz FM, 9k6 PBP DigitalDownlink: 435.150 mhz FM, 9k6 PBP Digital[01292006]

The ECHO Operations committee will determine modes and schedules for experiments.


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The good news is that in the weeks following activation of AO-51 the load has lightened and its easier to get it if youplan ahead and avoid the pileups. Many people are able to work Echo successfully. 5 watts is all that is needed withboth an Arrow antenna and a wave whip. Aruni VE4WMK who is 10 years old uses an HT with an Arrow and is verysuccessful.

Have a look at the AMSAT website entitled 12 Suggestions for Handheld Transceiver Users. Here are some of thebasics:

1. Listen First . If you cant hear other stations, you cant work them. AO-51 is very strong (onlythe ISS is stronger) so almost everyone can hear it on a good HT with a good whip antenna, thedual-band Arrow yagi or the dual band Elk log periodic that are sold at most flea markets in thearea.

2. Keep your squelch off . Although Echo is strong, its not strong enough to break your squelchin most cases.

3. Make sure you have your PL tone set to 67hz . Like most repeaters, even if you get achance to get in, you wont without the PL tone set. Dont try to use tone squelch either, as Echodoes not transmit a 67Hz PL tone back on its downlink.

4. Dont use a verticle antenna . Whips and ground plane antennas should be tilted so that the

verticle is 90 degrees off the elevation of the satellite.5. Know where the satellite is . Keep a tracking program nearby where you can reference it. If you are handheld outside, use a handheld computer running PocketSat or PetitTrack to referencethe satellites position.

6. Use Dual Headphones! I cant stress this enough. Your brain is the best DSP there is, and if you only hear the signal through one ear, your brain cant filter out the noise nor can it reactquickly to callsigns.

How Will I Ever Get In?


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When you decide to work AO-51 for the first time, some preparatory steps willhelp.

Visit the AMSAT website and visit the Echo Project page to make sure you have thecorrect frequencies. The AMSAT website also has online pass predictions in the Toolssection which will calculate the passes for your location.

Try listening on one pass nearby (over 30 degrees of elevation) and see how wellyou are receiving. If you cant hear the satellite, you may need to improve yourreceive antennas. Try to arrange a sked with another station. Its easier to make a contact withsomeone who is experienced on the satellites than cold calling. That contact canalso help you determine how well your signal is doing. Plan on working a pass away from populated areas (see the map - white spots arehigh density population areas.) If you can work to the north or west or over theocean, your results will be better because statistically there are fewer people.

Most of all, dont get discouraged. AO-51 is reprogrammable from the ground and theyhave made some improvements to it already. For example, initially the power was set to330mw, then 500mw and now is set for 1W. AO-51 can operate up to 7 watts, but it isunlikely they will increase power over 2W since most stations now receive AO-51 full

quieting.

How Should I Prepare?


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When naming a transponder the input (uplink) is always specified first. A slash / is used to separateinput and output.Input (Uplink) frequency, wavelength, or designator / Output (Downlink) frequency, wavelength ordesignator.

LINK DESIGNATORS

( Frequency) (Wavelength) (Designator) 21 MHz 15 m H29 MHz 10 m T145 MHz 2 m V435 MHz 70 cm U1.2 GHz 24 cm L2.4 GHz 13 cm S5.7 GHz 6 cm C10.5 GHz 3cm X24 GHz 1.2 cm K

TRANSPONDER NAMESOld Name New Name Mode A V/TMode B U/V

Mode J V/UMode K H/TMode KA H,V/TMode KT H/T,VMode L L/UMode S U/SMode T H/V

New Transponder Mode Designations

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Satellites for Beginners