More NOAA APT Images with GNU Radio, URSP and WBX

Last weekend I wrote about my spontaneous experiments with receiving and decoding APT transmissions from NOAA polar orbiting weather satellites. This weekend I decided to extend the experiments by trying to receive at very low elevations and get images from far away.

I allocated most of Saturday to this experiment and tried to get as many passes as possible. I started with a morning pass of NOAA-17, unfortunately, the satellite still appears to be broken.

NOAA 17 southbound 42W at 10 Jul 2010 08:00:26 GMT on 137.62MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)
NOAA 17 southbound 42W at 10 Jul 2010 08:00:26 GMT on 137.62MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

@2e0sql told me that it has been broken for some week on and off, and @claymdavis added that it has a sticking pan head motor that interrupts scans.

Shortly after the NOAA-17 pass, NOAA-18 came up very briefly for a low elevation pass that didn’t exceed 3¬į. The reception was noisy but I managed to get some image out of it. This image was sent while NOAA-18 was close to be above the North pole ūüôā

NOAA 18 northbound  5E at 10 Jul 2010 08:23:05 GMT on 137.9125MHz, contrast enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared).
NOAA 18 northbound  5E at 10 Jul 2010 08:23:05 GMT on 137.9125MHz, contrast enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared).

NOAA 18 northbound  5E at 10 Jul 2010 08:23:05 GMT on 137.9125MHz, HVCT enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared).

NOAA 18 northbound  5E at 10 Jul 2010 08:23:05 GMT on 137.9125MHz, HVCT enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared).

This is how the pass looked like while I was receiving it:

 

Later during the day I had some good passes for NOAA-18, NOAA-19 and NOAA-15. The NOAA-19 pass was cut short because NOAA-18 was right behind it and I wanted to switch over. The reception was excellent in all cases; however, some of the false color images didn’t turn out too well. I’m not sure why. Maybe it is due to the illumination/sensor combination during the time of the day.

NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

 

NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, HVCT enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, HVC enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, HVCT enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared) NOAA 19 northbound 57E at 10 Jul 2010 11:25:14 GMT on 137.10MHz, HVC enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

 

NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, contrast enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared)

NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, contrast enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared)

 

NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, HVC enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared)

NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, HVCT enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared)

NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, HVC enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared) NOAA 18 northbound 51E at 10 Jul 2010 11:28:50 GMT on 137.9125MHz, HVCT enhancement, Normal projection, Channel A: 1 (visible), Channel B: 4 (thermal infrared)

 

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, contrast enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

 

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, class enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, HVC enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, HVCT enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, class enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared) NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, HVC enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared) NOAA 15 northbound 66E at 10 Jul 2010 14:31:11 GMT on 137.50MHz, HVCT enhancement, Normal projection, Channel A: 2 (near infrared), Channel B: 4 (thermal infrared)

 

Finally, I decided to try NOAA-17 once more during the evening hoping it got better since the morning, but this was not the case.

NOAA 17 northbound 66W at 10 Jul 2010 19:24:14 GMT on 137.62MHz, contrast enhancement, Normal projection, Channel A: 3/3B (mid infrared), Channel B: 4 (thermal infrared)
NOAA 17 northbound 66W at 10 Jul 2010 19:24:14 GMT on 137.62MHz, contrast enhancement, Normal projection, Channel A: 3/3B (mid infrared), Channel B: 4 (thermal infrared)

 

This concludes my experiments with NOAA APT images for now. Since I have no fixed antenna for this purpose (I used the Arrow II hand held yagi for all receptions) I have no desire for a permanent installation. I might try to run the audio files through wxapt to see how well it decodes the images but no firm plans at the moment.