Its been a while since this video was uploaded, but its a really good demonstration. I Have one question though. When using satdump i am given several output images. Some like the ones at the end, but some others colorized with much better quality. What exactly are the colorized ones? Are they from the sattelite too or an overlay that satdump adds?
I think satdump is the best right now but I didnt try it. Since the satellite only sends black and white, for sure satdump is doing some kind of false color. I added a false color feature to noaa-apt some time ago but there is room for improvement. Anyway the black and white original image quality should be the same for any decoder
shouldn't you disable "filter audio", as when decoding digital modes? also from what I read "The bandwidth required to receive APT transmissions is approximately 34 kHz" yours looks too wide..
I think that those things do not affect much the quality. According to my experience, the quality of the image would be much more influenced by the antenna Regarding "filter audio": You are right. I'm checking now and I think it does not influence a lot the quality of the image, since noaa-apt has filters that are similar to the SDR# ones. More precisely. I checked online a bit and looks like the "filter audio" setting is a bandpass filter aprox from 400Hz to 4000Hz with a deemphasis. noaa-apt uses aprox 500Hz to 4800Hz. You can see the spectrum of the signal here: noaa-apt.mbernardi.com.ar/how-it-works.html#about-frequency Regarding the bandwidth setting in SDR#: Seems like you are right, but again, it does not influence a lot the quality of the image. More bandwidth should produce a more noisy image and I think that a lower bandwidth should produce artifacts in the image.
@@noaa-apt totally agree about the antenna. In my experience it makes the biggest difference wth almost every SDR usage. Also sometimes it helps to add a narrow bandpass filter, followed by preamp. This way the nearby strong signals are filtered out and not overloads the receiver. In any case, thank you for the nice video demonstration!
very well done.
Its been a while since this video was uploaded, but its a really good demonstration. I Have one question though. When using satdump i am given several output images. Some like the ones at the end, but some others colorized with much better quality. What exactly are the colorized ones? Are they from the sattelite too or an overlay that satdump adds?
I think satdump is the best right now but I didnt try it. Since the satellite only sends black and white, for sure satdump is doing some kind of false color. I added a false color feature to noaa-apt some time ago but there is room for improvement. Anyway the black and white original image quality should be the same for any decoder
Awesome. Hope you can get better quality next time :)
shouldn't you disable "filter audio", as when decoding digital modes? also from what I read "The bandwidth required to receive APT transmissions is approximately 34 kHz" yours looks too wide..
I think that those things do not affect much the quality. According to my experience, the quality of the image would be much more influenced by the antenna
Regarding "filter audio": You are right. I'm checking now and I think it does not influence a lot the quality of the image, since noaa-apt has filters that are similar to the SDR# ones. More precisely. I checked online a bit and looks like the "filter audio" setting is a bandpass filter aprox from 400Hz to 4000Hz with a deemphasis. noaa-apt uses aprox 500Hz to 4800Hz. You can see the spectrum of the signal here: noaa-apt.mbernardi.com.ar/how-it-works.html#about-frequency
Regarding the bandwidth setting in SDR#: Seems like you are right, but again, it does not influence a lot the quality of the image. More bandwidth should produce a more noisy image and I think that a lower bandwidth should produce artifacts in the image.
@@noaa-apt totally agree about the antenna. In my experience it makes the biggest difference wth almost every SDR usage. Also sometimes it helps to add a narrow bandpass filter, followed by preamp. This way the nearby strong signals are filtered out and not overloads the receiver.
In any case, thank you for the nice video demonstration!
Bingo!
No audio?
There is only satellite audio when the image is being received. Sorry, I'm too shy for the talking