My way to solve the TLE lottery …

Let me show you the way – how I try to solve the TLE lottery.

A very good example is MASAT-1 – which is sending a (nearly) continously signal.

Today I choosed a high elevation pass (89 deg) where the doppler shift should be significant.
I recorded the complete pass with my SDR-IQ without doppler correction.

For post analysis of the pass I play back the recorded pass with SpectraVue. My software calculate the correct frequency to the same time as in the recorded file and set the center frequency in SpectraVue. My graphs showing the demodulated audio signal. If a TLE match perfect you should hear a constant tone – and you’ll see a line. If the TLE does not match you can hear the deviation of the audio signal (lower/higher tone).

In the following pictures you can see the simulation of this pass with the latest keps (space-track – epoch time 46.48471756).

You can see the doppler shift of the audio signal and which TLE is the best match. So for MASAT-1 my favourite is OBJECT D…

4 thoughts on “My way to solve the TLE lottery …”

  1. Hi Mike,
    thank you for the brilliant analysis about solving the Vega-lottery problem. We, here in Hungary, faced the problem too, and we started to discuss it in our forums, but we havnot success, and aggree to choose “our bird”.
    To expose the problem and offer a tool for radio amateurs and others interesting in it, we aggread with Simone Corbellini to create 2 online tracking web page on his web site.
    One of this page offeres to display all the birds of the “Vega-family” on one google map. If you zoom it, you can make differences between the sats, and if you move the mouse on one icon, you can identify “who is hwo”.
    There is another page, with the feature, to choose the list of Vega-family one member, and you can follow on the map. This page extended with short text, introducing the problem.
    I would like to ask your permission to use your picture on this page.
    Here are the link to this pages:
    The birds flying in cloud, line…
    Here is a small introduction of the problem.

  2. Mike,

    Thank you for this post! It may help me solve my reception problems here as I had been using object ‘C’.

    Have a good weekend.


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