This page documents the parameters contained in the final, merged, corrected data set for S-PolKa radar in the DYNAMO project. The first released data set is referred to as "QC_ver1". This data set is considered to be the most useful data set for the majority of users. Other data sets are also available, including covariance data sets, original in-field data sets, Ka original resolution, and some limited time series data. Those data sets will be made available, as appropriate, or may be requested by contacting EOL staff.
Developmental or research data sets, such as the dual-frequency liquid water or water vapor retrieval data sets, will require further work, and may be discussed with the S-Pol DYNAMO PI.
Disclaimer: this document is a work in progress, and will be updated as time permits.
The following is a list of the parameters included in the final, quality-controlled, cfRadial format, S-PolKa merged data set. This applies to the data set released in the first week of July, 2012. Comments and references are shown, as appropriate. Please refer to the cfRadial format description for further information.
Parameters have had noise correction and/or censoring applied, as appropriate. Note that noise correction is based upon a beam-by-beam varying noise power. Details may be found in Dixon and Hubbert, 2012. As an example, the reflectivity fields have been constructed from censored power fields, with noise-correction (mostly affecting low power signal); the power fields have been censored, but not noise corrected.
S-band parameters are shown with _S, except for the PID and precip RATES (which are exclusively based upon S-band parameters). Ka-band parameters are shown similarly, but with _K.
For this merged data set, Ka-band data have had their original gate resolution degraded to match the gate spacing of the S-band data. Original resolution, corrected, Ka-band data are available in a separate data set.
| Parameter Units |
Standard Name Long Name |
Comments: |
|---|---|---|
| DBZ_S dBZ |
equivalent_reflectivity_factor radar_reflectivity |
Fully calibrated; elevation angle-dependent atmospheric attenuation applied, as in Doviak and Zrnic, 1993 (pp.44-45) |
| DBZ_NAA_S dBZ |
equivalent_reflectivity_factor DBZ_with_no_atmospheric_attenuation_correction |
Fully calibrated; no atmospheric attenuation estimate applied. |
| VEL_S m/s |
radial_velocity_away_from_instrument radial_velocity |
Traditional fast-alternating dual-pol velocity estimate, from H and V interspersed signal, with phase offset (Wilson/Illingworth/Blackman, 1997). This velocity is noisy if PHIDP is noisy. Nyquist velocity is ~26.7 m/s. |
| VEL_ALT_S m/s |
radial_velocity_away_from_instrument radial_velocity_unfolded_using_vel_hv |
Derived from VEL_HV_S, unfolded to wider Nyquist interval using VEL_S. This is the recommended velocity field for general use, except in cases where there is significant noise in PHIDP. This velocity is generally less noisy than the VEL_S, but may sometimes be unfolded into the wrong velocity interval. The working Nyquist interval is ~26.7 m/s. |
| VEL_HV_S m/s |
radial_velocity_away_from_instrument radial_velocity_hv_separately |
Velocity from H-only pulses, averaged with velocity from V-only pulses; reprocessed from phase information in covariance data set. This velocity is useful in regions where PHIDP is noisy, as when there is significant phase-shift on backscatter (e.g., gust fronts and bird echoes). Nyquist velocity is ~13.3 m/s. |
| WIDTH_S m/s |
doppler_spectrum_width doppler_spectrum_width |
|
| ZDR_S dB |
log_differential_reflectivity calibrated_log_differential_reflectivity |
ZDR defined by Seliga and Bringi, 1976. Derived from calibrated copolar reflectivities; zdr bias from vertical pointing data applied (same bias as used for the in-field data set). See bias determination report. |
| LDRH_S dB |
linear_depolarization_ratio_h linear_depolarization_ratio_h_channel |
Calibrated and noise-corrected. Transmit H-polarization, receive V. |
| LDRV_S dB |
linear_depolarization_ratio_v linear_depolarization_ratio_v_channel |
Calibrated and noise-corrected. Transmit V, receive H. |
| RHOHV_S |
cross_correlation_ratio_hv cross_correlation_ratio |
Noise-corrected RHOHV. Provides a more consistent value in regions of low SNR. Reprocessed from original (in-field) covariance data set. (see Zrnic, 1988 for formulation). |
| RHOHV_NNC_S |
cross_correlation_ratio_hv cross_correlation_ratio_not_noise_corrected |
Original, in-field RHOHV, not noise corrected. |
| PHIDP_S deg |
differential_phase_hv differential_phase |
See Jameson and Mueller, 1985; processed according to Hubbert and Bringi, 1995. |
| KDP_S deg/km |
specific_differential_phase_hv specific_differential_phase |
Processed according to Hubbert and Bringi, 1995. |
| PSOB_S deg |
phase_shift_on_backscatter phase_shift_on_backscatter |
See Hubbert, et al., 1993, and Hubbert and Bringi, 1995. |
| SNRHC_S dB |
signal_to_noise_ratio_hc signal_to_noise_ratio_db_h_copol_channel |
|
| SNRHX_S dB |
signal_to_noise_ratio_hx signal_to_noise_ratio_db_h_crosspol_channel |
|
| SNRVC_S dB |
signal_to_noise_ratio_vc signal_to_noise_ratio_db_v_copol_channel |
|
| SNRVX_S dB |
signal_to_noise_ratio_vx signal_to_noise_ratio_db_v_crosspol_channel |
|
| DBMHC_S dBm |
log_power_hc power_in_dbm_h_copol_channel |
|
| DBMHX_S dBm |
log_power_hx power_in_dbm_h_crosspol_channel |
|
| DBMVC_S dBm |
log_power_vc power_in_dbm_v_copol_channel |
|
| DBMVX_S dBm |
log_power_vx power_in_dbm_v_crosspol_channel |
|
| NCP_S |
normalized_coherent_power normalized_coherent_power |
|
| PID |
hydrometeor_type particle_id |
See Vivekanandan, et al., 1999 for details. Modifications made by Scott Ellis for DYNAMO. The in-field version of PID differs somewhat from the final PID. |
| TEMP_FOR_PID C |
temperature temperature_for_computing_pid |
Temperature from nearest-in-time, nearest-in-space sounding information. |
| RATE_ZH mm/hr |
precipitation_flux precip_rate_from_z |
See rain rate computations. |
| RATE_Z_ZDR mm/hr |
precipitation_flux precip_rate_from_z_and_zdr |
See rain rate computations. |
| RATE_KDP mm/hr |
precipitation_flux precip_rate_from_kdp |
See rain rate computations. |
| RATE_KDP_ZDR mm/hr |
precipitation_flux precip_rate_from_kdp_and_zdr |
See rain rate computations. |
| RATE_HYBRID mm/hr |
precipitation_flux precip_rate_hybrid_of_zh_zzdr_kdp_and_kdpzdr |
See rain rate computations. |
| CLUT_S dB |
clutter_power_removed clutter_power_removed |
See Steiner and Smith, 2002; Hubbert, et al., 2009a, and Hubbert, et al., 2009b. |
| CPA_S none |
clutter_phase_alignment clutter_phase_alignment |
See Steiner and Smith, 2002; Hubbert, et al., 2009a, and Hubbert, et al., 2009b. |
| CMD_S none |
clutter_mitigation_decision interest_value_used_for_clutter_detection |
See Steiner and Smith, 2002; Hubbert, et al., 2009a, and Hubbert, et al., 2009b. |
| CMD_FLAG_S none |
clutter_mitigation_decision_flag flag_indicating_where_clutter_filter_is_applied |
See Steiner and Smith, 2002; Hubbert, et al., 2009a, and Hubbert, et al., 2009b. |
| DBZ_K dBZ |
equivalent_reflectivity_factor radar_reflectivity |
Fully calibrated; for DYNAMO, this parameter is the same as DBZ_NAA_K, and there is no atmospheric attenuation estimate applied (this parameter is provided for consistency). |
| DBZ_NAA_K dBZ |
equivalent_reflectivity_factor DBZ_with_no_atmospheric_attenuation_correction |
Fully calibrated; no atmospheric attenuation estimate applied. |
| LDRH_K dB |
log_linear_depolarization_ratio_h linear_depolarization_ratio_h_channel |
Transmit H-polarization, receive V. Note that there is poor isolation between H and V for the Ka, and that this quantity likely has very limited utility. |
| SNRHC_K dB |
signal_to_noise_ratio_hc signal_to_noise_ratio_db_h_copol_channel |
|
| SNRVX_K dB |
signal_to_noise_ratio_vx signal_to_noise_ratio_db_v_crosspol_channel |
|
| DBMHC_K dBm |
log_power_hc power_in_dbm_h_copol_channel |
