METEOR LRPT: automatic recording and SatDump decoding example (v0.8.7)

[sgoudelis]

The same workflow supports both METEOR-M2 3 and METEOR-M2 4. The screenshots use METEOR-M2 3, but you can create a monitored-satellite entry for either spacecraft using its current active LRPT transmitter.

The receiver, gain, antenna, and local RF conditions will differ between stations. Treat the Airspy and 13 dB gain below as an example, then tune those values for your own hardware.

Before configuring the observation

1. Use Ground Station v0.8.7 or newer and configure the station's correct location.
2. Connect an SDR that can receive around 137 MHz and an antenna suitable for weather-satellite reception. Confirm the SDR appears in Ground Station before scheduling a pass.
3. Open Satellites → Orbital Data Sources and synchronize the satellite data. Confirm that both METEOR-M2 3 and METEOR-M2 4, together with their active LRPT transmitters, are available. Frequencies and active spacecraft can change, so always verify the transmitter shown by your deployment.
4. For Docker, mount a persistent host directory at /app/backend/data. This keeps the database, settings, observations, recordings, and decoded output outside the replaceable container.

1. Add the monitored satellite

Open Scheduler → Monitored Satellites → Add, then set:

• Enabled: on
• Satellite: 57166 - METEOR-M2 3, as pictured, or select METEOR-M2 4
• Minimum Peak Elevation: 40°
• Task Start Elevation: 0°
• Lookahead Window: 24 hours
• Rotator: None

The 40° minimum schedules stronger, higher passes. A rotator is optional; this example uses a fixed antenna. To receive both spacecraft automatically, create a separate monitored-satellite entry for METEOR-M2 3 and METEOR-M2 4.

2. Configure the SDR session

Select Add SDR and configure the session:

• SDR: select the receiver attached to your deployment
• Sample Rate: 3 MHz
• Gain: 13 dB in this Airspy example; adjust for your receiver and noise level
• Antenna Port: RX in this example
• Bias-T: off, unless your antenna-side hardware explicitly needs power from the SDR
• Auto-calculate Center Frequency: off
• Center Frequency: 137900000 Hz

Use Select from transmitter list to avoid typing a stale frequency. The 137.900 MHz value shown here belongs to the METEOR-M2 3 transmitter selected in the screenshot; select the transmitter and frequency listed for METEOR-M2 4 when configuring that spacecraft.

3. Record IQ and run SatDump

Choose IQ Recording, then set:

• Transmitter: LRPT IQ recording usage - 137.900 MHz for the pictured METEOR-M2 3 example, or the active LRPT transmitter listed for METEOR-M2 4
• Enable Frequency Shift: off for this centered example
• Decimation: x3 (1 MHz)
• IQ Storage Format: 32-bit float IQ (cf32_le)
• Run SatDump post-processing after IQ recording: on
• SatDump Pipeline: METEOR-M2 LRPT (meteor_m2-x_lrpt)
• Delete IQ recording after SatDump completes: on in the photographed setup

For the first few passes, consider leaving Delete IQ recording after SatDump completes off. The raw SigMF IQ recording is useful when diagnosing a failed decode. At 1 Msps, cf32_le uses about 480 MB per minute, so make sure the persistent data volume has enough free space.

If your receiver has a strong DC spike or the LRPT signal is not centered before decimation, enable Frequency Shift and center the selected transmitter before recording.

4. Save and verify

Save the monitored satellite. Ground Station should create observations for matching passes inside the 24-hour lookahead window. If needed, select the monitored satellite and regenerate its observations.

Before the pass:

• Confirm an upcoming observation appears in the Scheduler.
• Make sure another session is not using the same SDR.
• Check that the antenna, USB access, and available disk space are ready.

After the pass completes, check the observation status and open the File Browser section. The images and other products generated by SatDump should appear there.

If SatDump does not produce an image, keep the raw IQ file and first check that the LRPT signal is visible and centered, the recording reports a 1 MHz output sample rate, and the meteor_m2-x_lrpt pipeline was selected. Antenna placement and gain usually need local adjustment.

[edegraaff]

until now no results that where reasonable, there are files created but no decoded images, i now add the sdr to the V dipole that worked ok for the noaas and meteor in the past. Keep you posted.
btw, the file system of the docker container was out of space last night ... keeping the files fill up the file system within 12 hours... but we fixed that one.
regards
eelco

[sgoudelis]

Remember not to delete the IQ recording so that you can paste here the waterfall image to see if there is actual signal there

[edegraaff]

I had to clean 0 bytes free system was not able to delete the files itselve, needed to fix it within the docker.
I will stay behind the computer and make sure i get one complete capture.
It is all a bit new, but i try to manage and learn the whole box of tricks.

btw i mis some satelites in the satelite list, especcially that do sstv https://www.amsat.org/image-transmitting-satellites/

Regards
Eelco

[sgoudelis]

Indeed some are missing from the default sources added initially, However, ground-station supports adding whatever kind of TLE/OMM sources you want from celestrak or space-track or from wherever TLE or OMM formatted data is offered. Check out Oribital Data -> Sources and see what it available there

[sgoudelis]

Also read this: #97