CAS500-2 Rideshare: VSFB SLC-4E - 2026-05-03 6:59 UTC

Good catch!

NULINK-1    
1 98322U          26123.38857226  .00000000  00000-0  00000-0 0    02
2 98322  97.7405  21.6745 0003186 120.9252 180.4328 14.92395341    09
NULINK-2    
1 98321U          26123.38836855  .00000000  00000-0  00000-0 0    06
2 98321  97.7383  21.6781 0003069 103.2528 197.0225 14.92336124    07

I’ve changed the TLE based on the first line, so I fixed the temporary NORAD ID in the TLE sets and fixed the checksum.

1 Like

Thanks for pointing out this observation. Just checked and the TLE’s mentioned earlier here for NuLink-2 is correct.

We just did a pass with NuLink-1 using the refined TLE from Fredy. This TLE is about 10s ahead of the NuLink-1 TLE. Could you attempt an observation using Fredy’s TLE for NuLink-1?

2 Likes

Will do - thanks.

So are you observing NuLink-2’s signals on 2220 MHz FIRST?

And then NuLink-1 after on 2218 MHz?

Sorry! I understand the misunderstanding now! My bad for assigning the wrong ID for the wrong satellites. I need to make a big mental note that:
NuLink-1 is 98322
NuLink-2 is 98321
:sweat_smile:

2 Likes

Right now we do one satellite per opportunity instead of one after another.

1 Like

Thank you - yes, I found my problem as well.

The previous entry had them reversed, hence my tracking disaster.

Well, failing horribly sometimes keeps me alert. Will do better next time!

Lest anyone be confused by my reference to this earlier post, please note the correct Object ID’s for these sats. Thank you!

1 Like

Oh my - doesn’t that look better?

For anyone using GPredict on linux, don’t forget that when you’ve added an object that is incorrect, a fresh / correct upload will not ‘fix’ it.

Go into

~/.config/Gpredict/satdata

… and delete the offending objects. THEN a fresh pull from your TLE source will make things right.

3 Likes

Indeed Gpredict always keep the name of the first TLE added for a NORAD ID, so if need to change the names then you need to remove the entries as you described and re-insert the TLE with the new name. :slight_smile:

1 Like

Good morning Scott,

For now, If you suggest/create a transmitter in db.satnogs.org with a high bandwidth and FSK you will get a full bw IQ recording on the systems that are IQ enabled.

I have used this workaround for MeteorM replay decodes.

Jan | PE0SAT

2 Likes

Thanks Scott, good reminder.

There are also command line options to get the same result.

gpredict --help
Usage:
  gpredict [OPTION…]

Gpredict is a graphical real-time satellite tracking and orbit prediction program.
Gpredict does not require any command line options for nominal operation.

Help Options:
  -h, --help               Show help options
  --help-all               Show all help options
  --help-gtk               Show GTK+ Options

Application Options:
  --clean-tle              Clean the TLE data in user's configuration directory
  --clean-trsp             Clean the transponder data in user's configuration directory
  --display=DISPLAY        X display to use

Jan | PE0SAT

4 Likes

Thank you for reviewing and updating the transmitter entry.

We would first change the transmitter frequency to 436.500 MHz, the IARU-coordinated frequency, while keeping the baud rate at 9600 bps. After confirming the change, we will mark the 436.500 MHz transmitter as active in SatNOGS. However, there is still a possibility that it may fall back to 1200 bps.

May I ask if the observations you have already scheduled for us at 437.200 MHz can be modified to 436.500 MHz?

I will add another transmitter entry in SatNOGS for 436.500 MHz at 9600 bps.

If we cannot solve the issue and need to operate at 436.500 MHz with 1200 bps, we will confirm the configuration first, then mark that transmitter as active and set the other entries as inactive.

Your support is greatly appreciated.

Thanks so much for the tip!

How do you specify the bandwidth?

Downlink mode FSK and the baudrate will determine the BW.

Here the Meteor LRPT IQ recording example.

Jan | PE0SAT

1 Like

I Try decode me RX Gemini-Pollux
looks singal strong,but my soundmodem not decode,need help

Really sorry again. Did another check of the TLE for both satellites and spotted a mistake. The correct TLEs that we are using now are:

NULINK-1
1 98322U          26123.89344859  .00000000  00000-0  61811-7 0    05
2 98322  97.7410  22.3187 0003547  97.0670  35.2153 14.92459626    02
NULINK-2    
1 98321U          26123.38836855  .00000000  00000-0  00000-0 0    06
2 98321  97.7383  21.6781 0003069 103.2528 197.0225 14.92336124    07

The satellites are about 14s apart. @fredy can we trouble you to update the TLEs in the DB? Thank you!

1 Like

You need USB or LSB mode
and SoundModem for 1k2:

for 9k6:

1 Like

Its not work…

TLE updates from the space-track.org analyst list based on @PE0SAT strf analysis:

Drishiti
1 98313U          26124.91288568 +.00002874 +00000+0 +13562-3 0 00054
2 98313  97.4081  23.5108 0005637 161.2782 198.8661 15.20239034000235
FrontierSat
1 98318U          26124.45158564 +.00005258 +00000+0 +24012-3 0 00040
2 98318  97.4048  23.0510 0007902 183.6365 176.4815 15.20989729000176
QUBE2
1 98314U          26124.97915740 +.00004735 +00000+0 +22406-3 0 00044
2 98314  97.4089  23.5787 0005138 140.1783 219.9830 15.19826997000253
3 Likes

TLE updates from the space-track.org analyst list based on ikhnos analysis:

SELENE
1 98316U          26124.97967893 +.00006940 +00000+0 +33133-3 0 00030
2 98316  97.4081  23.5760 0005797 119.6918 240.4894 15.19347930000243
HELIOS
1 98317U          26124.97957239 +.00007124 +00000+0 +33907-3 0 00050
2 98317  97.4064  23.5729 0006246 125.9763 234.2052 15.19446223000240
3 Likes