i make new topic for this interesting case (for me 
)
i set up my ground station with time that source only from gnss pulse (PPS / gps clock). you can look the tutorial here
chronyc sources -v
.-- Source mode '^' = server, '=' = peer, '#' = local clock.
/ .- Source state '*' = current best, '+' = combined, '-' = not combined,
| / 'x' = may be in error, '~' = too variable, '?' = unusable.
|| .- xxxx [ yyyy ] +/- zzzz
|| Reachability register (octal) -. | xxxx = adjusted offset,
|| Log2(Polling interval) --. | | yyyy = measured offset,
|| \ | | zzzz = estimated error.
|| | | \
MS Name/IP address Stratum Poll Reach LastRx Last sample
===============================================================================
#? GPS 0 4 377 15 +135ms[ +135ms] +/- 101ms
#* PPS 0 4 377 14 -1354ns[-2138ns] +/- 242ns
then my station decode the honghu-2 satellite, based on this community post
my station until i write this post , successfully decode this satellite on 2 observations
this and this
the decoded telemetry show the on board clock of satellites (i guess)
that time in unix timestamp. convert it
timestamp.py.txt (206 Bytes)
python3 timestamp.py
Enter a Unix timestamp: 1790457916
2026-09-26 21:25:16 UTC
and what interesting , see the time when my gr_satellites decode this frame:
2026-09-26T21-25-14 UTC → my gs
2026-09-26 21:25:16 UTC → satellite
that is 2 second difference.
my groundstation 2 second faster than satellites time.
ok hold here.
i look on network, and found other satno that success decode , @PE0SAT 31 groundstation. on metadata these jan groundstation used airspy sdr. but i dont know if these using gpsdo or no. using ntp or pps as source clock. what i know , jan station that using gpsdo only station 21, but currently it not serve on freq 400 mhz.
on jan station, the gs clock and honghu clock is same
python3 timestamp.py
Enter a Unix timestamp: 1790438892
2026-09-26 16:08:12 UTC
that make me confuse. what you think? maybe you can try it on your groundstation. i repost the satyaml here
name: HONGHU-2
norad: 58555
data:
&tlm Telemetry:
telemetry: csp
transmitters:
19K2 FSK downlink:
frequency: 401.6120e+6
modulation: FSK
baudrate: 19200
deviation: 4800
framing: AX100 ASM+Golay
data:
- *tlm
