NSA/XSAPR/C1 - General Quality Statement

The XSAPR continues to undergo evaluation by the radar instrument mentors, VAP developers, 
DQ Office, users, etc...  As more in-depth analysis and calibration studies take place, 
we anticipate that new insights will be gained to increase the quality of the data and 
decrease the uncertainty of the measurements.  This is a continuous improvement process and 
issues will be addressed as they are discovered.

As issues are discovered, attempts will be made to correct data that are currently in the 
Archive.  However, retrospective correction of errors due to calibration, signal 
processing, component degradation and software bugs may not be possible for many of the data files.

This open-ended DQR is an advisory that some aspects of the data quality are not yet 
known.  It is also a request to users that find issues or questions with the data to contact 
the ARM Radar Engineering & Operations Group as these issues occur so that they can be 
investigated and corrected if necessary.

Known Issues Not Documented in Other DQRs

1.  Due to the radome design, a radial pattern shows up in the data during times of 
stratiform precipitation and longer term statistical analysis

• Differential propagation phase shift(dp_phase_shift)
• Specific differential phase(diff_phase)
• Signal quality index(sig_qual_index)
• Attenuation corrected reflectivity(reflectivity_corr)
• Mean doppler velocity(mean_doppler_velocity)
• Differential reflectivity, clutter filtered(diff_reflectivity)
• Unfiltered reflectivity(reflectivity_unf)
• Range gate(gate)
• time_in_seconds_since_volume_start(time)
• Lag-0 co-polar correlation coefficient, clutter filtered(copol_coeff)
• Doppler spectral width, clutter filtered(doppler_spectral_width)
• reflectivity(reflectivity)
• Attenuation corrected differential reflectivity(diff_reflectivity_corr)

• pulse_repetition_frequency(prt)
• Time corresponding to last radial in file(time_coverage_end)
• East longitude(longitude)
• Index of first ray in sweep, 0-based(sweep_start_ray_index)
• data_volume_index_number(volume_number)
• time_in_seconds_since_volume_start(time)
• transmit_pulse_mode(prt_mode)
• Total power(total_power)
• Distance to the center of the corresponding range bin(range)
• Beam Elevation Angle(elevation)
• Azimuth of Radar Ray(azimuth)
• Sweep number, zero-based count(sweep_number)
• Unambiguous range(unambiguous_range)
• Differential reflectivity(differential_reflectivity)
• Doppler spectrum width(doppler_spectrum_width)
• data_volume_start_time_utc(time_coverage_start)
• Clutter filtered reflectivity in horizontal polarization(reflectivity_horizontal)
• Differential propagation phase shift(differential_phase)
• Mean doppler velocity(mean_doppler_velocity)
• altitude(altitude)
• Cross correlation ratio (RhoHV)(cross_correlation_ratio)
• Specific differential phase (KDP)(specific_differential_phase)
• Normalized coherent power(normalized_coherent_power)
• File status(file_status)
• Scan mode for sweep(sweep_mode)
• North latitude(latitude)
• Time index of last ray in sweep, 0-based(sweep_end_ray_index)
• ray_target_fixed_angle(fixed_angle)
• Unambiguous Doppler velocity(nyquist_velocity)

• reflectivity(reflectivity)
• Mean doppler velocity(mean_doppler_velocity)
• time_in_seconds_since_volume_start(time)
• Differential propagation phase shift(dp_phase_shift)
• Range gate(gate)
• Lag-0 co-polar correlation coefficient, clutter filtered(copol_coeff)
• Signal quality index(sig_qual_index)
• Unfiltered reflectivity(reflectivity_unf)
• Specific differential phase(diff_phase)
• Attenuation corrected reflectivity(reflectivity_corr)
• Attenuation corrected differential reflectivity(diff_reflectivity_corr)
• Differential reflectivity, clutter filtered(diff_reflectivity)
• Doppler spectral width, clutter filtered(doppler_spectral_width)

• ray_target_fixed_angle(fixed_angle)
• Time corresponding to last radial in file(time_coverage_end)
• Clutter filtered reflectivity in horizontal polarization(reflectivity_horizontal)
• Differential propagation phase shift(differential_phase)
• pulse_repetition_frequency(prt)
• File status(file_status)
• Sweep number, zero-based count(sweep_number)
• Differential reflectivity(differential_reflectivity)
• North latitude(latitude)
• Azimuth of Radar Ray(azimuth)
• Doppler spectrum width(doppler_spectrum_width)
• transmit_pulse_mode(prt_mode)
• data_volume_start_time_utc(time_coverage_start)
• data_volume_index_number(volume_number)
• East longitude(longitude)
• Beam Elevation Angle(elevation)
• Specific differential phase (KDP)(specific_differential_phase)
• Time index of last ray in sweep, 0-based(sweep_end_ray_index)
• Scan mode for sweep(sweep_mode)
• Unambiguous range(unambiguous_range)
• Index of first ray in sweep, 0-based(sweep_start_ray_index)
• Normalized coherent power(normalized_coherent_power)
• Total power(total_power)
• altitude(altitude)
• Mean doppler velocity(mean_doppler_velocity)
• Cross correlation ratio (RhoHV)(cross_correlation_ratio)
• time_in_seconds_since_volume_start(time)
• Unambiguous Doppler velocity(nyquist_velocity)
• Distance to the center of the corresponding range bin(range)

• Time index of last ray in sweep, 0-based(sweep_end_ray_index)
• Total power(total_power)
• transmit_pulse_mode(prt_mode)
• Beam Elevation Angle(elevation)
• Time corresponding to last radial in file(time_coverage_end)
• Unambiguous Doppler velocity(nyquist_velocity)
• File status(file_status)
• data_volume_start_time_utc(time_coverage_start)
• Unambiguous range(unambiguous_range)
• time_in_seconds_since_volume_start(time)
• data_volume_index_number(volume_number)
• Scan mode for sweep(sweep_mode)
• Clutter filtered reflectivity in horizontal polarization(reflectivity_horizontal)
• Doppler spectrum width(doppler_spectrum_width)
• Normalized coherent power(normalized_coherent_power)
• Sweep number, zero-based count(sweep_number)
• Differential propagation phase shift(differential_phase)
• North latitude(latitude)
• altitude(altitude)
• Azimuth of Radar Ray(azimuth)
• Differential reflectivity(differential_reflectivity)
• Specific differential phase (KDP)(specific_differential_phase)
• pulse_repetition_frequency(prt)
• Distance to the center of the corresponding range bin(range)
• Mean doppler velocity(mean_doppler_velocity)
• East longitude(longitude)
• Cross correlation ratio (RhoHV)(cross_correlation_ratio)
• Index of first ray in sweep, 0-based(sweep_start_ray_index)
• ray_target_fixed_angle(fixed_angle)

• Signal quality index(sig_qual_index)
• Differential reflectivity, clutter filtered(diff_reflectivity)
• Unfiltered reflectivity(reflectivity_unf)
• Lag-0 co-polar correlation coefficient, clutter filtered(copol_coeff)
• Differential propagation phase shift(dp_phase_shift)
• Attenuation corrected differential reflectivity(diff_reflectivity_corr)
• reflectivity(reflectivity)
• Doppler spectral width, clutter filtered(doppler_spectral_width)
• Specific differential phase(diff_phase)
• time_in_seconds_since_volume_start(time)
• Range gate(gate)
• Mean doppler velocity(mean_doppler_velocity)
• Attenuation corrected reflectivity(reflectivity_corr)

• Attenuation corrected differential reflectivity(diff_reflectivity_corr)
• Attenuation corrected reflectivity(reflectivity_corr)
• Doppler spectral width, clutter filtered(doppler_spectral_width)
• Differential reflectivity, clutter filtered(diff_reflectivity)
• Specific differential phase(diff_phase)
• Unfiltered reflectivity(reflectivity_unf)
• Differential propagation phase shift(dp_phase_shift)
• time_in_seconds_since_volume_start(time)
• Range gate(gate)
• reflectivity(reflectivity)
• Signal quality index(sig_qual_index)
• Mean doppler velocity(mean_doppler_velocity)
• Lag-0 co-polar correlation coefficient, clutter filtered(copol_coeff)