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Satellite Sv To Garmin Numbering System


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I'm trying to learn more about the whole GPS system and have found a lot of good stuff on the net and this board. One thing I haven't found is a cross reference for satellite SV, PRN, Navstar numbers to the Garmin numbers I see on my GPSr.

 

My goal is to get TLEs for the sats and know which is which.

 

Anybody know where I can find this info?

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I'm trying to learn more about the whole GPS system and have found a lot of good stuff on the net and this board. One thing I haven't found is a cross reference for satellite SV, PRN, Navstar numbers to the Garmin numbers I see on my GPSr.

 

My goal is to get TLEs for the sats and know which is which.

 

Anybody know where I can find this info?

 

ORBIT

SBAS SATELLITE LONGITUDE PRN Gar

 

EGNOS Inmarsat-3-F2/AOR-E 15.5° W 120 33

Inmarsat-3-F1/IOR 64.0° E 131 44

Inmarsat-3-F5/IOR-W 25.0° E 126 39

 

WAAS Inmarsat-3-F4/AOR-W 54.0° W 122 35 (Being moved to 142°W)

Inmarsat-3-F3/POR 178.0° E 134 47

 

Garmin numbers are obtained by subrtracting 87 from the PRN number.

 

AOR-W should be at 142° west withing a couple of weeks. Don't know when it will be broadcasting corrections though.

 

Don't know why so many are parked over the oceans?? I guess ships at sea need 3 meter accuracy. Sure wish they'd park one at 95°W.

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Don't know why so many are parked over the oceans?? I guess ships at sea need 3 meter accuracy. Sure wish they'd park one at 95°W.

The satellites they're using for SBAS (both WAAS and EGNOS flavors) weren't launched with that as their main purpose. They're using primarily existing Inmarsat birds that happen to have an available repeater channel that's suitable for use by WAAS/EGNOS. And one of the big markets for Inmarsat is to provide global communications for maritime operations.

 

Keep in mind that the WAAS/EGNOS satellites are just acting as repeaters. The timing, ephemeris/almanac, and correction data is beamed to the WAAS/EGNOS satellite by a ground station for retransmission back to earth. Very different from the regular GPS satellites that have their own atomic clocks and initiate the data they transmit (although those also get periodic updates from ground stations).

 

The two new satellites supporting WAAS that were launched last fall and are still undergoing testing will be more centrally located for the US.

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Don't know why so many are parked over the oceans?? I guess ships at sea need 3 meter accuracy. Sure wish they'd park one at 95°W.

The satellites they're using for SBAS (both WAAS and EGNOS flavors) weren't launched with that as their main purpose. They're using primarily existing Inmarsat birds that happen to have an available repeater channel that's suitable for use by WAAS/EGNOS. And one of the big markets for Inmarsat is to provide global communications for maritime operations.

 

Keep in mind that the WAAS/EGNOS satellites are just acting as repeaters. The timing, ephemeris/almanac, and correction data is beamed to the WAAS/EGNOS satellite by a ground station for retransmission back to earth. Very different from the regular GPS satellites that have their own atomic clocks and initiate the data they transmit (although those also get periodic updates from ground stations).

 

The two new satellites supporting WAAS that were launched last fall and are still undergoing testing will be more centrally located for the US.

 

Peter, what are these two new satellites called and where will they be parked? And, more importantly, when will they be in operation for our use??

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Peter, what are these two new satellites called and where will they be parked? And, more importantly, when will they be in operation for our use??

Last I heard the PanAm Galaxy15 satellite was to be positioned at W133° and the Canadian Anik F1R at W107°. So both are to the west of central but visible throughout the country (depending on horizon conditions). The Galaxy15 has already been sending valid correction and ranging data from time to time. I haven't seen the Anik yet, but my wife usually has the receiver with WAAS capability and I haven't checked recently.

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HERE IS THE CURRENT STATUS ON ALL GPS SATS:

 

A. BLOCK II/IIA/IIR/IIR-M INDIVIDUAL SATELLITE STATUS

 

SVN PRN

15 15 Launched 01 OCT 1990; usable 15 OCT 1990; operating on Cs std

24 24 Launched 04 JUL 1991; usable 30 AUG 1991; operating on Cs std

25 25 Launched 23 FEB 1992; usable 24 MAR 1992; operating on Cs std

26 26 Launched 07 JUL 1992; usable 23 JUL 1992; operating on Rb std

27 27 Launched 09 SEP 1992; usable 30 SEP 1992; operating on Rb std

29 29 Launched 18 DEC 1992; usable 05 JAN 1993; operating on Rb std

30 30 Launched 12 SEP 1996; usable 01 OCT 1996; operating on Rb std

32 01 Launched 22 NOV 1992; usable 11 DEC 1992; operating on Cs std

33 03 Launched 28 MAR 1996; usable 09 APR 1996; operating on Cs std

34 04 Launched 26 OCT 1993; usable 22 NOV 1993; operating on Rb std

Scheduled unusable 16 Mar 2000 UT to 17 Mar 0800 UT (NANU

2006019/9 MAR)

35 05 Launched 30 AUG 1993; usable 28 SEP 1993; operating on Cs std

36 06 Launched 10 MAR 1994; usable 28 MAR 1994; operating on Rb std

37 07 Launched 13 MAY 1993; usable 12 JUN 1993; operating on Rb std

38 08 Launched 06 NOV 1997; usable 18 DEC 1997; operating on Cs std

39 09 Launched 26 JUN 1993; usable 20 JUL 1993; operating on Cs std

40 10 Launched 16 JUL 1996; usable 15 AUG 1996; operating on Cs std

41 14 Launched 10 NOV 2000; usable 10 DEC 2000; operating on Rb std

43 13 Launched 23 JUL 1997; usable 31 JAN 1998; operating on Rb std

44 28 Launched 16 JUL 2000; usable 17 AUG 2000; operating on Rb std

45 21 Launched 31 MAR 2003; usable 12 APR 2003; operating on Rb std

46 11 Launched 07 OCT 1999; usable 03 JAN 2000; operating on Rb std

47 22 Launched 21 DEC 2003; usable 12 JAN 2004; operating on Rb std

51 20 Launched 11 MAY 2000; usable 01 JUN 2000; operating on Rb std

53 17 Launched 26 SEP 2005; usable 16 DEC 2005; operating on Rb std

54 18 Launched 30 JAN 2001; usable 15 FEB 2001; operating on Rb std

56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std

59 19 Launched 20 MAR 2004; usable 05 APR 2004; operating on Rb std

60 23 Launched 23 JUN 2004; usable 09 JUL 2004; operating on Rb std

61 02 Launched 06 NOV 2004; usable 22 NOV 2004; operating on Rb std

 

WAAS sat 35 is suppose to start re-broadcasting ranging on april 1.

(Edit that. Here is what they say: "February 2006 – On February 1st, one of the WAAS geostationary satellites (INMARSAT AOR-W) will begin moving west to a new location. This move, which will take approximately 60 days, is the first of several steps this year leading to a new configuration of WAAS GEO satellites")

Edited by EraSeek
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Thanks all for adding info to this thread.

 

I made a lucky find on the net this morning, the Navstar GPS Constellation Status as of 01-02-06. In contains the information posted above plus the NORAD #s I was looking for. I should be able to download the current TLEs from Space Track now.

 

Thanks again for the posts. :rolleyes:

 

Link

Edited by Team Trail Walker
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Keep in mind that the WAAS/EGNOS satellites are just acting as repeaters. The timing, ephemeris/almanac, and correction data is beamed to the WAAS/EGNOS satellite by a ground station for retransmission back to earth.

Don't the WAAS satellites also send ranging data? And doesn't that require that they have clocks onboard?

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If anyone is interested, I put together a Satellite ID Reference Chart.

 

ID-Chart.jpg

 

Now I'm really confused! Are what your calling PRN numbers the numbers used by Garmin? I thought you had to subtract 87 from the PRN numbers to get the Garmin numbers??

 

What about adding the present and known future WAAS satellites and their Garmin numbers to your chart?

 

Is it correct that the WAAS/EGNOS satellites are/will be in a geosynchronous position over the equator? I think the one's you are showing circle the earth every 24 hrs.

 

Here is what I'be using as reference and hence the confusion about PRN numbers.

http://gpsinformation.net/exe/waas.html

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Now I'm really confused! Are what your calling PRN numbers the numbers used by Garmin? I thought you had to subtract 87 from the PRN numbers to get the Garmin numbers??

 

What about adding the present and known future WAAS satellites and their Garmin numbers to your chart?

 

Is it correct that the WAAS/EGNOS satellites are/will be in a geosynchronous position over the equator? I think the one's you are showing circle the earth every 24 hrs.

Garmin subtracts 87 from the PRN numbers of the SBAS (WAAS/EGNOS/etc.) satellites which makes a nice consecutive sequence of all the PRNs.

 

Yes, all WAAS & EGNOS satellites are in geostationary orbits (which therefore must be over the equator). The Japanese MSAS satellites are in geosynchronous but inclined orbits (so they go back and forth but at least one will always be close to overhead from Japan).

 

The regular GPS satellites orbit once every 12 sidereal hours. But since the earth is also rotating they'll be over the same location again about every 24 hours (not exactly since the orbits are based on sidereal rather than solar time).

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Why does Garmin display a number for WAAS and EGNOS satellites, but Magellan doesn't? The eXplorists only show a W. "Magellan is teh sux0r" is not an acceptable answer.

Maybe the Magellan firmware designers didn't see a need to show an identifying number. Afterall, the WAAS/EGNOS satellites are in fixed locations (current move by #122 excepted), so anyone who is really interested in the subject will probably already know which is which just by the location - and anyone who's not interested wouldn't care about the number.

 

I'd much rather have my Garmin act in a little more intelligent way about the WAAS satellites and don't really care if it shows the numbers (it's currently constantly looking for a signal from #123 and #134, which aren't visible, and not looking for others such as #125 & #135 which are high in the sky and sending good data).

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Well, I just backed up my Meridian Color and then hard reset it. Left it in the driveway for a good while and then looked at it. It isn't showing all 4 WAAS sats, but it is showing 3 where it used to show only 2. I didn't have to prevent it from 'seeing' in any direction, just left it out.

 

I assume this is because the new birds are now officially online?

 

In any event WAAS birds high in the sky are good news.

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