Data parameters

S-PolKa Parameters 2004-2007

S-PolKa Parameters 2007-2011

S-PolKa Parameters 2011+

The following is a list of the parameters included in the final, quality-controlled, cfRadial format, S-PolKa merged data set for DYNAMO, 2011. It is expected that future projects will have parameters with similar names, and this list will continue to be updated.

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
 

 

References

  • Dixon, M., J.C. Hubbert, 2012: The Separation of Noise and Signal Components in Doppler RADAR Returns. ERAD 2012, The Seventh European Conference on RADAR in Meteorology and Hydrology. Toulouse, France. SP-078.
  • Doviak, R.J., D.S. Zrnic, 1993. Doppler Radar and Weather Observations. Academic Press, 2nd ed. ISBN-13: 978-0122214226
  • Hubbert, J., V. Chandrasekar, V. N. Bringi, P. Meischner, 1993: Processing and Interpretation of Coherent Dual-Polarized Radar Measurements. J. Atmos. Oceanic Technol., 10, 155164. doi: http://dx.doi.org/10.1175/1520-0426(1993)010<0155:PAIOCD>2.0.CO;2
  • Hubbert, J., V. N. Bringi, 1995: An Iterative Filtering Technique for the Analysis of Copolar Differential Phase and Dual-Frequency Radar Measurements. J. Atmos. Oceanic Technol., 12, 643-648. doi: http://dx.doi.org/10.1175/1520-0426(1995)012<0643:AIFTFT>2.0.CO;2
  • Hubbert, J. C., M. Dixon, S. M. Ellis, G. Meymaris, 2009: Weather Radar Ground Clutter. Part I: Identification, Modeling, and Simulation. J. Atmos. Oceanic Technol., 26, 1165-1180. doi: http://dx.doi.org/10.1175/2009JTECHA1159.1
  • Hubbert, J. C., M. Dixon, S. M. Ellis, 2009: Weather Radar Ground Clutter. Part II: Real-Time Identification and Filtering. J. Atmos. Oceanic Technol., 26, 1181-1197. doi: http://dx.doi.org/10.1175/2009JTECHA1160.1
  • Jameson, A. R., E. A. Mueller, 1985: Estimation of Propagation-Differential Phase Shift from Sequential Orthogonal Linear Polarization Radar Measurements. J. Atmos. Oceanic Technol., 2, 133-137. doi: http://dx.doi.org/10.1175/1520-0426(1985)002<0133:EOPDPS>2.0.CO;2
  • Seliga, T. A., V. N. Bringi, 1976: Potential Use of Radar Differential Reflectivity Measurements at Orthogonal Polarizations for Measuring Precipitation. J. Appl. Meteor., 15, 69-76. doi: http://dx.doi.org/10.1175/1520-0450(1976)015<0069:PUORDR>2.0.CO;2
  • Steiner, Matthias, James A. Smith, 2002: Use of Three-Dimensional Reflectivity Structure for Automated Detection and Removal of Nonprecipitating Echoes in Radar Data. J. Atmos. Oceanic Technol., 19, 673-686. doi: http://dx.doi.org/10.1175/1520-0426(2002)019<0673:UOTDRS>2.0.CO;2
  • Vivekanandan, J., S. M. Ellis, R. Oye, D. S. Zrnic, A. V. Ryzhkov, J. Straka, 1999: Cloud Microphysics Retrieval Using S-band Dual-Polarization Radar Measurements. Bull. Amer. Meteor. Soc., 80, 381-388. doi: http://dx.doi.org/10.1175/1520-0477(1999)080<0381:CMRUSB>2.0.CO;2
  • Wilson, Damian R., Anthony J. Illingworth, T. Mark Blackman, 1997: Differential Doppler Velocity: A Radar Parameter for Characterizing Hydrometeor Size Distributions. J. Appl. Meteor., 36, 649-663. doi: http://dx.doi.org/10.1175/1520-0450-36.6.649
  • Zrnic, D.S.; Balakrishnan, N.; Sachidananda, M., 1988: Processing And Interpretation Of Alternately Polarised Weather Radar Echoes. Geoscience and Remote Sensing Symposium, 1988. IGARSS '88. Remote Sensing: Moving Toward the 21st Century., International Volume: 1 Page(s): 243-246. doi: 10.1109/IGARSS.1988.570103