There are many parts of operating a successful XHRPT station. In the diagram below you can see various radio options, demodulators, decoders, trackers and image processing options. Yes, there is some complexity, but that is part of the interest.
If you are interested in any of the following USA-Satcom software, please use the contact page for more info.
XHRPT Decoder
XHRPT Standalone Decoder (XSD)
UltraTrack
Various Streamers for SDRplay and Ettus Research SDRs
Please note that USA-Satcom does not export software to all countries.
Additionally, for GRC options you can visit TyNet.eu for community contributed GRC flow graphs.
Got up way too early to capture this rare Mercury Transit. Mercury is small, about 1/3 the size of the Earth. Good thing there was no sunspots or Mercury would have been difficult to locate.
Here is a great write up by Rodney AAA6RD, Region 6 Director for US Army MARS on his GOES-16/17 setup. The write-up includes what’s required, the setup details and the results.
Getting close to releasing XHRPT decoder. Upgraded to now decode MetOp-A/B, FengYun-3A/B/C in addition to the previously supported NOAA-18/19/15 and Meteor-MN2. Here is a short video of a typical pass of MetOp-B AHRPT. The video has been speed up, so the entire pass is just 26 seconds.
NOAA’s GOES-13 (East), GOES-15 (West) and now GOES-16 produce some amazing images. Both GOES-13 and GOES-15 broadcast weather images to users with suitable ground stations using a protocol called LRIT (Low Rate Information Transmission). GOES-16, a more advanced satellite does the same but uses a protocol called HRIT (High Rate Information Transmission). The parameters of each satellite are shown below.
In general, the LRIT and HRIT signals are not strong. There is not much room for a non-optimal setup. You need a good low noise figure LNA, a filter if you have nearby interference, high quality coax and a suitable antenna. Antennas can be a 1m or larger dish, a grid-style antenna or even a Yagi with suitable gain. The polarization from the satellites are Linear, so if you decide to use a circular feed just be aware that you will loose 3dB of the signal.
The latest version of the decoder software is shown below. It’s made up of two GUI panels. One for controlling demodulation and the other for controlling ingesting and image generation.
Currently, there is support for the AirSpy, AirSpy Mini and SDRplay RSP2. The supported sample rates are 2.5 MSPS and 3 MSPS. IQ data flows from a dedicated streamer application over UDP to the demodulator.
AirSpy Streamer GUI Interface
If you have the proper equipment, are able to receive a high quality signal from any of the GOES satellite, and are interested in this software then please contact me for a demo package. Email me for current pricing using the address on the contact form.
The HackRF one PCB is manufactured with an option for a shield. This shield is available from NooElec. It’s a simple and quick addition, just some easy soldering. The hardest part is just removing the HackRF one from it’s plastic case.
Below you can see the shield framing installed.
Shield frame installed.
Now with the lid installed and the job is complete.
Shield frame and lid installed.
Next up is adding a small (20mm x 20mm x 6mm) aluminum heatsink to the ARM processor. The ARM processor runs pretty hot on the HackRF and this heatsink will reduce the operating temperature, extending the life of the part. The heatsinks can be found for around $0.50 each on amazon. The most important item is the Arctic Alumina thermal *adhesive*, this ensures the heatsink makes good thermal contact and remains attached under high temperatures. The thermal adhesive can also be found in amazon for $7.99.
HackRF prep for heat sink.
Below you can see my improvised method of ensuring good contact during the curing phase.
Weighting the adhesive.
After about 1 hour the “delicate” process is now complete.
My new AirSpy SDR arrived last week. The goal this weekend was to make a small application to stream the IQ over Ethernet and then test it with one of the Inmarsat decoders that I have previously developed.
AirSpy SDR.
The API is very similar to the HackRF One and so it did not take long to get the streaming to work. The AirSpy currently supports either 10MSPS or 2.5MSPS. I choose to work with 2.5MSPS as I will need to decimate it even at that rate.
Here is the small application that runs on the host machine where the AirSpy is plugged into USB.
AirSpy Streamer Application.
This application will take the IQ samples at 2.5MSPS and then decimate by 8 to give 312.5KSPS. This is then sent over Ethernet using UDP. The decoder can then be located anywhere on the network, including the host machine (loopback). Below is the received L-Band spectrum after decimation as received by the decoder.
IQ Stream from AirSpy.
Here is the main decoder log window showing various events along with notification of any messages written to disk.
Decoder status console.
Below are the two decoder windows showing real time status.
Real time decoder status.
And finally the overall SDR/Message status and statistics.
SDR and message statistics.
The AirSpy is performing very well and decoder has been running 2 channels for 24 hours now without any frame loss or disruptions. Excellent performance. I will be placing an order for another one this week for another project I have in mind.
1 day ago
The mysterious #ISS signal on 137.626MHz continues. Months since first detected it would appear it emits from something fairly permanently attached to the space station. https://t.co/GFb9GQrKsG
3 days ago
Here is something cool! You can listen to the 80 hours of Tianwen-1 accelerometer data (X,Y channels as stereo audio) in 1 minute, 5000x sped up. Periodic pings are used for stabilization, louder hiss periods are burns that preceded TCM1 maneuver.
(headphones highly recommended) https://t.co/VrElH11rJc
16 hours ago
1 day ago
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