Satellite Tracking
Satellite Tracking

More soon but press CTRL O

You will then be given the option to view all satellites or just the ISS. In either case, once satellite tracking is activated, a "Satellite Details" window will be available from the Left-Click popup menu. From there you can select what satellite objects are actually generated and under what conditions. The checkbox in Satellite Details means:

Checked - Always generate satellite objects
Unchecked - Never generate satellite objects
Tri-State (faded check) - Generate killed satellite objects 10 minutes before AOS and after LOS, generate Visible (V overlay) satellite objects while in view.

TLEs for the satellites come from Celestrak Amateur TLE and are filtered to the currently active satellites listed below. To completely turn off satellite tracking, simply close the Satellite Details window and answer the confirmation prompt. If the client is closed with satellite tracking active, it will automatically re-activate on restart with the most recent checkbox settings intact.

The common reasons for errors in tracking satellites are the following:

Very old TLE data, especially with the ISS please use less than week old data, TLE and tracking in general is an estimate and the newer the data the better the estimate. (Not so much an issue with APRSISCE/32 until we support user-supplied TLEs). Note that not all TLE sources are created equal. See below for a specific example.

Also make sure the time on your PC is accurate, windows has a time sync function thats good enough for satellite tracking. But I recommend Meinberg for accurate timing and automatic correction.

And the time zone setting is also important. Don't say you're in the Eastern Time Zone and set the time for UTC or vice versa. Your time zone is used to offset the displayed time to UTC for satellite orbit calculations.

Also of course make sure you have not got your location wrong! This is not the center of the screen, but the location of "ME"!

Here's the list of currently known active satellites:

/* From Steve via AMSAT Status */

Name Cat No.
SRM 99999
ARRISSat-1 37772
FASTRAC 2 37380
FASTRAC 1 37227
OREOS 37224
HO-68 36122
ITUpSAT1 35935
BEESAT 35933
SwissCube 35932
SO-67 35870
KKS-1 33499
STARS 33498
PRISM 33493
Rs-30 32953
CO-66 32791
DO-64 32789
Compass-1 32787
Co-65 32785
GENESAT-1 29655
CO-58 28895
VO-52 28650
AO-51 28375
RS-22 27939
CO-57 27848
CO-55 27844
NO-44 26931
ARISS 25544
SO-33 25509
GO-32 25397
FO-29 24278
RS-15 23439
IO-26 22826
AO-27 22825
AO-16 20439
UO-11 14781
AO-7 7530

links for elements
All Amateur Satellites

On 10/14/2011 I researched a report that APRSISCE/32 was 2+ minutes different in an AOS forecast than Ham Radio Delux. After tracking down the sources of their respective TLEs, I found that APRSISCE/32's source of Celestrak Amateur TLE had the following from day 286 of year 11.

1 25544U 98067A 11286.81211653 .00009560 00000-0 11861-3 0 2381
2 25544 51.6369 283.5817 0016212 325.3429 93.8255 15.60650478739436

HRD was using TLEs from AMSAT NASAbare TLE which included the following from day 285 of year 11.

1 25544U 98067A 11285.91900602 .00007956 00000-0 10000-3 0 02347
2 25544 051.6409 288.0749 0016408 320.9217 117.1587 15.60589610739299

A source TLE difference of Just under 9/10 of a day resulted in a 2 minute difference in the predictions. Yes, TLE freshness DOES make a difference. (It didn't help that the ISS had just undergone two orbital boosts in the past week, but still…)

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