Introduction
In the previous post we looked at planning for reception of GOES16(R) weather signals. We determined a ball-park estimate of a received level at -84dBm (assuming a satellite transmit power of 60dBmi) at an azimuth of 174deg and elevation angle of 39.4deg for a location in Toronto, Canada.
Signal Capture for GOES16(R)
Figure 1 shows the signal capture using the handheld parabolic antenna + Sawbird/LNA + RTL-SDR/5VDC BiasTee on SDR#. The signal has an approximate 3dB bandwidth of (1.694625GHz – 1.693625GHz) = 1MHz. The HRIT signal is BPSK at 927Ksps @ alpha=0.3, so Nyquist BW = 1.3*927KHz = 1.205MHz, so this looks like the right signal in the right place! At this point I haven’t tried to decode it, just determined if I could see it on the spectrum. Clearly the assumed satellite transmit power is far too high, but 60dBmi was only a guess. The next step will be to arrange a permanent balcony mount for the antenna, so I can decode the signal. At this point I can say that this antenna would not be suitable for a small boat. It would make a good sail however!
I decided to modify my receive arrangement to see if I could squeeze a few more dB! Looking at Lukas’s video (Ref.6), it seemed to show that he was using the LMR400 coax between the SAWBIRD and the RTL. I had previously put both together at the back of the antenna as in Figure 1. Doing this resulted in a far better signal. In order to see more BW I increased the Fs of the RTL to 3.2Msps.
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References
#1. – “RTL-SDR for Satellite Weather on GOES16 – Planning”
https://jeremyclark.ca/wp/telecom/rtl-sdr-for-satellite-weather-on-goes16-planning/
#2. – “Open Plotter – GRIB Files”
https://jeremyclark.ca/wp/telecom/openplotter-grib-files/
#3. – “Weather Satellite”
https://en.wikipedia.org/wiki/Weather_satellite
#4. – “NOAA GOES16 Footprint “
https://www.ospo.noaa.gov/Organization/FAQ/footprint.html
#5. – “GOES-R Series Specifications”
https://noaasis.noaa.gov/GOES/about_goes-r_series.html
#6. – “Review of NooElec GOES Kit”, Lucas Teske
https://www.youtube.com/watch?v=QqSAa2ociLI
