SGP/XSAPR/I6 - Azimuthal Drift

The azimuth and elevation position were drifting over time.  The position reported in the 
files for the radar is not accurate and has an offset in azimuth at times.  There are 
periods in the data where the offset is constantly changing from scan to scan.

• Mean Doppler velocity, clutter filtered(mean_doppler_velocity)
• Daily values of reflectivity on each grid cell(reflectivity)
• Differential propagation phase shift, clutter filtered(dp_phase_shift)
• Attenuation corrected reflectivity(reflectivity_corr)
• Doppler spectral width, clutter filtered(doppler_spectral_width)
• Differential reflectivity, clutter filtered(diff_reflectivity)
• Lag-0 co-polar correlation coefficient, clutter filtered(copol_coeff)
• Unfiltered reflectivity(reflectivity_unf)
• Signal quality index(sig_qual_index)
• Specific differential phase, clutter filtered(diff_phase)
• Attenuation corrected differential reflectivity(diff_reflectivity_corr)