Satdump software & wxsat reception

Terryl said:
I wish there was a SatDump forum to post possible bugs in the program, I have some strange noise problems that show up when running satdump, the spikes are only there when using that program, using SDR console or SDR++ they are not there.

For troubleshooting info one of the engineers at Nooelec (one of my SDR dongles) said to try a program called GQRX, it's has a very clean noise floor and is free of the nasty spikes I see in satdump.

I don't think is direct harmonic radiation from the PC as the antenna is 10 meters away from the PC and the coax is double shielded, I have even put the dongles in a double shielded box, no help, I even tried a second source dongle from RTL-SDR, same problem.

I'm stumped, if I can get rid of these spikes I can get good passes on the Meteor satellites.

I think I see these spikes because my noise floor is very low, it's around -75 dBm, so everything shows up, what are some of you guys noise floors at?

Don't know whats going on as I'm not a software guy...
Click to expand...
On a decimation setting of 1 & with the Uputronics pre amp installed my noise floor is about -50dBm
 
I seem to get decent passes in the mornings.This one is from the NNE I have a clear view from that direction.I loose signal when the satellite gets near SSW.I loose signal soon after the position that the satellite is on the satdump screenshot.
msu_mr_rgb_321_corrected.jpgm2-3.jpg
 
Has Met M2-4 changed to 137.9? Its just come over & I was watching the spectrum. The signal came up on 137.9 not 137.1.....
 
Same settings and using the new SAWbird LNA and filter I have a noise floor of -66 dBm using SatDump.
 
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And a noise floor of -100 dBm with SDR console, so something is causing a noise problem using the satdump program.

Here is a comparison.

137.1 MHZ with SDR console.
137.1 MHz SDR console noise floor.jpg

And what I get with satdump, same settings on both programs.

SatDump at 137.1 MHz.jpg
 
I do not know if it will make any difference to your system Terryl.You have a better antenna than me.Mine is home made, to get a decent signal I have to have AGC enabled in Device.
 
Maybe it's because my antenna is very wide band (50 to 3000 MHz) I can maybe fix up the antenna I had when I first started this stuff, a high wind caused some major damage to it,(blew the mast down) that's when I got the discone.

I get great signals on the NOAA satellites, but not on the Meteors, it could be interference from the NOAA's, the other day I setup my laptop with all this stuff and took a drive around the area, I couldn't find anything that would cause this spike problem.

I live out in what we call the boonies, the nearest town is 35 miles from me, the same with any radio stations, there are other homes closer to me but no one has a transmitter even close to the frequency's we are monitoring.
 
I have even shut down anything that may make an RF signal, (or something like one) I shut down the LAN system/router/modem/computers (except one with satdump running on it) and all my ham gear, I still get those annoying spikes.
 
Yup Met M2-4 is now using 137.9 & 80k

MSU MSR Channel 4 at 15.25utc 26/4/24

(as received apart from cropping off the noise top & bottom)

Capture.JPG
 
I got two good scans from Meteor-m2-x-lrpt-80k this afternoon 14.22 and 16.02 137900Mhz .Not sure where it is it looks like north iceland area.There is a white gap at the top of the first one 14.22 pass.
Edit that probably means that it is upside down
msu_mr_channel_4_equalized_corrected_map.jpgmsu_mr_rgb_no_enhancement_corrected_map.jpg
 
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Here is an example of the NOAA satellites over riding the signals from the Meteor satellites.

Meteor 2-3 is almost set to go overhead, but so is NOAA-18 and 19, their signals are much stronger then the Meteors, however with the two satellites almost on the same frequency there is a conflict and the signals get scrambled and garbled up, so nothing gets decoded on ether one. (sometimes you may get lucky)

NOAA over riding Meteor.jpg
 
28/4/24 0452 pass, 39 degree max elevation. 137.9MHz 80k
Meteor M2-4 MSU MR Channel 4

As received, just the top & bottom blank areas trimmed off.

Capture.JPG

Im getting much better results with M2-4 compared to M2-3. Leaving aside the current NOAA 18 interference M2-3 signals are consistently noisy here - lots of dropouts on them. Its rare to get a good image
 
I got a really good scan from the 15.56 M2-4 pass.No interference not cropped.I have no idea where it is though.No scan location on the rgb_msu_mr_Thermal_Channel_projected.jpg
 

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Right over the top of the UK =- if you rotate the image you can see the welsh coastline & Anglesea clearly in the middle of the image

msu_mr_rgb_no_enhancement_corrected_map.jpg
 
Nope I don't see it.And I am not going to spec savers.:)
I think that what is needed is a location marker like the one in WXTOIMG
 
marked.jpg

Ive annotated it for you :) The coast of France is just about visible too. Yup better mapping & location markers would be useful
 
I'm getting a very noise free pass on NOAA-19 right now with tons of signal, so I tried the 1700 GHz bands, but I get an error of ""SPS is invalid, Must be above 1"" when I use the NOAA HRPT settings and I see no way to fix or set that.
 
We had a SPS query early in this thread. Its the sampling rate isnt it? Unfortunately I dont have any 1700MHz antennas so I cant help.
 
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