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Low SNR at High Elevation?. PRN 24, at 80 degree elevation, with Doppler = -550 Hz: Mean SNR: 29.9 PRN 30, at 40 degree elevation, with Doppler = 2350 Hz: Mean SNR: 31.9 PRN 4, at 40 degree elevation, with Doppler = -2800 Hz: Mean SNR: 33.2
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Low SNR at High Elevation? PRN 24, at 80 degree elevation, with Doppler = -550 Hz: Mean SNR: 29.9 PRN 30, at 40 degree elevation, with Doppler = 2350 Hz: Mean SNR: 31.9 PRN 4, at 40 degree elevation, with Doppler = -2800 Hz: Mean SNR: 33.2 All data collected serially on same channel with default tracking loop (FLL).
Reasons? Could be because of age? • PRN 24 is Block 2A-02 launched on 7/9/1991 • PRN 4 is Block 2A-14 launched on 10/28/1993 • PRN 30 is Block 2A-18 launched on 9/12/1996