Building a groundstaion

Hello guys.

I am building a groundstation to detect signals from cubesats or other signals in 420 - 450 MHz, but I do not see any signals.

I make a helical antenna with 10 dBi and I use a USRP to control the SDR. In the first part of detections, I need to see only the temporary signals on spectrum analyzer, due to the Cubesats pass for 10 minutes. But I can’t see.

I tested the antenna, sending a carrier through the signal generator and it is OK. The USRP has a sensitivity of -110 dBm, using its amplifiers. Besides that I bought two LNAs with 20 and 24 dB of gain, and it is not enough.

What I need to do more?


Fabricio Silva.

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Hello Fabricio.

Oh, do you use the v3 or the v2 design (or something costume).

Although I am not familiar with your setup. Is your rotator controlled by the SatNOGS client or is it controlled by some other software solution like gpredict?

Hi Eikos.

I do not use rotators because I have a little time to finish my project. To track the satellites, I use two softwares: Satellite AR (in smartphone) and website

The N2YO is good to predict when your satellite will pass in your city. The Satellite AR is very interesting to know the position of satellite, pointing the camera for the sky. Both have a big database and I think they are reliable

I agree that it is a manual process, but for now this is what I have.

Articles and forums say that seem easy if you have a good antenna and a system reception. I do not know if the problem is my geographic location. I live in Florianópolis, Brazil, with the sea level zero approximately and here has many mountains.

In last week, I tried listen the Tigrisat satellite, in 435 MHz of downlink, but I saw a weak and short signal on 439 MHz. It is possible a Doppler shift of 4 MHz? Or maybe it must be from the radioamatuer stations.