Receive NOAA weathersatellites using a 16 euro SDR receiver
Info received:
- NOAA 19 (freq.: 137.1 MHz)
- date: 9 jan. 2013
- time:12:30 UTC
- Location: the Netherlands, Hilversum
- Max. elevation: 85 degrees.
- Antenna: cross-dipole, no earth plane; in loft
Processing
- SDRSharp, V1.0.0.1000 (Windows; simple netbook)
- WFM, bandwidth 40 kHz
- 1024 bps
- AGC Off (RTL and Tuner)
- Gain set to max. (47 dB)
- Recording: 16 bits PCM, Audio
- Postprocessing using Adacity (Linux):
- Amplify: menu Effect -> Amplify (wav-file generated by SDRSharp has low volume)
- Write-out wav-file with 11025 rate
- Show results; wxtoimg (Linux)
NOAA19, 9-1-2013, 13:30
NOAA19, 10-1-2013, 13:20
NOAA19, 10-1-2013, 13:20 (same pass, msa)
NOAA19, 10-1-2013, 13:20 (same pass, hvct)
Next screenshot of SDRSharp is made AFTER recording!
Some notes
- For some reason SDRSharp shows 'something' exactly at the center frequency.
Setting receive freqeuncy at center, it sounds like a carrier is received.
Changing the center frequency, this 'carrier' always stays at the center frequency.
So it is not something received!
For this reason I did set center frequency besides the receiving frequency!
- There are 2 FM settings: W(ide) FM and N(arrow) FM.
Besides, the bandwidth can be adjusted.
Even if the filter bandwidth is kept the same the results of WFM and NFM are NOT equal.
Apparently NFM uses a demodulator with narrow bandwith, WFM with wide bandwidth, and after these
demodulators the bandwidth filter is located.
NFM seems to be too narrow for APT; it sounds "aggressive"; and noise is
modulated.
WFM, with filter bandwidth set to 40 kHz seems to give best results.
- My receive conditions are far from ideal; in-house antenna, no pre-amplifier, long Coax cable.
Results Peter Kooistra (9-9, 12:18)
Used:
WSP 137 antenna (sort of turnstile)
SDR Hana Nano
