Observation 4611653: NOAA 15 (25338)

Regarding Observation 4611653


I have been working on this problem for quite a long time. The picture could be nice without those defects. I checked the antenna via SoapySDR and seems working all right. So I am thinking that the issue might be the software. However, formatting doesn’t improve it as well. What do you think might be the problem?


There looks to be enough SNR there for an image, but it looks like you might be dropping samples? I can hear some artefacts in the audio which might indicate this (glitching in the ‘tick tock’ in the APT signal).

Might be worth checking the logs for a lot of OOOOOOOOOOOOOOs indicating this, or watch your CPU usage when an observation is taking place.

What platform are you running on?

Thanks for the reply, the platform is a Raspberry Pi 3 with RTL-SDR and FM filter. We checked the system again and noticed a low voltage warning. We will try again without using the UPS because it might be the reason, hope it will work.

The UPS we are using is this one: SUNFOUNDER Raspberry Pi UPS HAT Power Supply Module with Recharging Function 5V/3A Lithium Battery Power Pack Expansion Board for Pi 4B 3B+ 3/2B and 1 Model B+, Battery Not Included: Amazon.de: Computer & Zubehör