NOAA: Why starting in the middle of the transission?


If I look at the NOAA APT pictures: Why is it decoding in the middle of the signal?

The decoder cuts the half of the picture. Old TLE? Wrong time?

What is the problem?

Too weak signal. Being an analog “double modulation” (AM+FM), APT requires quite high SNR. When SNR is too low, the decoder will either not decode or decode noise if it is already locked.

Ok. The problem is: My DIY-Turnstile-preamp-combination seems to be not as good as other setups…


Perhaps a pass that comes up to 60 deg in elevation; that might give better result :slight_smile: