Winter Orographic Clouds / Wyoming Water 16 Jan - 13 Feb 2006 Wyoming Cloud Radar Data Status Report Content: General Notes WCR configuration Radar Status/Problems Calibration Notes Data File Information Terminology and other notes ................................................................................ General Notes: * WCR raw data is archived and available on DVD disks. Quicklooks, dataquality, and calibration data is also recorded on these disks. Radar processed data files in NetCDF format are available usually within 2 months after the conclusion of the experiment (preliminary version may be available earlier). The NetCDF files are available via the Internet or on DVD disks. * Quick look images of co-pol reflectivity for all the flights are stored on the project WCR web site in their corresponding directories(mmmDD) as pdf files. ................................................................................ WCR configuration: WCR was installed on UWKA with four-antenna configuration: Antenna 1 2,3 and 4 and no polarization capability (for more see www-das.uwyo.edu/wcr); Antenna ports are: Ant1 (side/up) - H1, Ant2(near nadir) - V2, Ant3(side-forward) - V3, Ant4(down-forward) - H2; H/V stands for the receiver used (there are 2 receivers). Cross-channels (HXVX and VXHX channels) have no meaning for this configuration. Ant. 1 uses UWKA radar mirror wing to direct the radar beam side or up. The radar mirror events are recorded in the King Air data files. Mirror switching times are extracted in ascii files and placed under their corresponding flight day directories (file names: KAyyyymmdd.hhmmss_hhmmss.mirror) When the mirror file is not present a single positon (up or side) has been used during the flight. ................................................................................ Radar Status/Problems * _______________ Jan 18, Flight = Jeff French reported that the data disk stopped responding in early flight. He rebooted wasp, after which, there were no problems with the disk. ................................................................................ Calibration notes: **************************************************************************** Power Calibration: * Calibration constants for this experiment as of 17 Jan 2006 Calibration constants (250 ns pulse, 5 MHz IF filter, dynamic range > 70 dB; for 500 ns pulse subtract 3.5 dB): Ant. 1 (side/up), HHcal1 = 49.5 Ant. 2 (nadir), VVcal2 = 50.5 Ant. 3 (side-fore), VVcal3 = 57.0 Ant. 4 (down-fore), HHcal2 = 55.0 Calibration constant precision over the whole dynamic range (no less than 70 dB) is about +-1.0 dB for both receivers The absolute accuracy of the calibration constants for side/up and nadir antennas is estimated to be around +-2.5 dB (based on the overall variability of the calibration constants and the expected drift in the receivers and transmitted power). Transmitted power drift is estimated to be in the order of 1 dB for less than 2 hour flight and no more than 1.5 dB for longer flights. Receiver gain drift is estimated to be less than 1 dB. The accuracy of the calibration constants for slanted antennas (side-forward and down-forward) is not well established. Cloud data are used for relative calibration of these antennas w.r.t. side and nadir antennas. Slanted antennas are mostly intended for Doppler velocities. Cross-channel Isolation > 50 dB Antenna Coupling Separation: better than 50 dB; weak coupling between side and nadir antenna is possible for strong(close range) surface returns) * Calibration constants used for quick look images: Ant. 1 (side/up), calHH1 = 49.5 @ 250ns Ant. 2 (nadir), calVV2 = 50.5 @ 250ns Ant. 3 (side-fore), calVV3 = 57.0 @ 250ns Ant. 4 (down-fore), calHH2 = 55.0 @ 250ns **************************************************************************** Beam angles calibration: * Unit beam angles(in AC coordinates) for this experiment as of 18 Nov 2005 X(along AC) Y(right wing) Z(down) Ant. 1 (up): 0.052336, 0.000000, -0.9986295 Ant. 1 (side): -0.020885, 0.999784, -0.000000 Ant. 2 (nadir): -0.05512, 0.000235, 0.99848 Ant. 3 (side-fore): 0.5854, 0.8105, 0.02 Ant. 4 (down-fore): 0.4382, 0.004099, 0.89887 The accuracy of the beam angles for 'up' beam are not well known due to lack of calib data. For all other beams, an average bias between -0.5 and +0.5 m/s may be present in the Doppler velocities after removing the AC motion from the measured Doppler. **************************************************************************** ................................................................................ WCR Data File Information: ************************************************************************** jan18: (crew: Drew, Leon, French, Snider ) Total data: 3.2 GB Alg/Pulse Antennas Notes 63M W2006-01-18-20-01-35 pp6/250 U, D,D 394M W2006-01-18-20-36-30 pp6/250 U, D,D 1.1G W2006-01-18-20-53-11 pp6/250 U, D,D 1.1G W2006-01-18-21-38-11 pp6/250 U/S,D,D elevated noise in hhn2 (22:10-16) likely from ground return exceeding the isolation 625M W2006-01-18-22-24-42 pp6/250 U, D,D 7.0M W2006-01-18-22-51-08 pp6/250 U, D,D very short (18 sec) ************************************************************************** jan26: (crew: Drew, Leon, French, Glover ) Total data: 4.4 GB Alg/Pulse Antennas Notes 775M W2006-01-26-19-04-39 pp6/250 U,D,D 1.1G W2006-01-26-19-37-15 pp6/250 U,D,D 684M W2006-01-26-20-24-37 pp6/250 U,D,D 625M W2006-01-26-20-53-22 pp6/250 U,D,D 360M W2006-01-26-21-19-40 pp6/250 U,D,D 389M W2006-01-26-21-34-48 pp6/250 U,D,D 483M W2006-01-26-21-51-10 pp6/250 U,D,D ************************************************************************** jan27: (crew: Fagerstrom, Geerts, Oolman, Wechsler) Total data: 5.5 GB Alg/Pulse Antennas Notes 17M W2006-01-27-21-36-58 pp6/250 U,D,D 637M W2006-01-27-21-40-33 pp6/250 U,D,D 592M W2006-01-27-22-07-20 pp6/250 U,D,D 488M W2006-01-27-22-32-12 pp6/250 U,D,D 641M W2006-01-28-00-06-16 pp6/250 U,D,D 521M W2006-01-28-00-35-23 pp6/250 U,D,D 554M W2006-01-28-00-59-43 pp6/250 U,D,D 599M W2006-01-28-01-22-59 pp6/250 U,D,D 585M W2006-01-28-01-48-08 pp6/250 U,D,D 569M W2006-01-28-02-12-41 pp6/250 U,D,D 418M W2006-01-28-02-36-33 pp6/250 U,D,D ************************************************************************** jan31: (crew: Drew, French, Leon, ) Total data: 4.4 GB Alg/Pulse Antennas Notes 1.2G W2006-01-31-13-13-02 pp6/250 U,D,D 934M W2006-01-31-14-03-08 pp6/250 U,D,D 864M W2006-01-31-14-42-24 pp6/250 U,D,D 296M W2006-01-31-15-18-43 pp6/250 U,D,D 548M W2006-01-31-15-31-10 pp6/250 U,D,D 666M W2006-01-31-15-54-13 pp6/250 U,D,D ************************************************************************** feb02: (crew: Drew,Geerts,OOlman,Wechsler) Total data: 4.3 GB Alg/Pulse Antennas Notes 602M W2006-02-02-18-58-16 pp6/250 U,D,D 466M W2006-02-02-19-23-31 pp6/250 U,D,D 337M W2006-02-02-19-43-03 pp6/250 U,D,D 576M W2006-02-02-19-57-10 pp6/250 U,D,D 557M W2006-02-02-20-21-20 pp6/250 U,D,D surface shows up on Up return 374M W2006-02-02-20-44-42 pp6/250 U,D,D 539M W2006-02-02-21-00-23 pp6/250 U,D,D 586M W2006-02-02-21-22-58 pp6/250 U,D,D 301M W2006-02-02-21-47-32 pp6/250 U,D,D ************************************************************************** feb05: (crew: Fagerstrom, Leon, Heather McIntyre, Wechsler) Total data: 4.0 GB Alg/Pulse Antennas Notes 1.1G W2006-02-05-13-01-11 pp6/250 U,D,D KA data N/A: 131116-132105 924M W2006-02-05-13-46-05 pp6/250 U,D,D 1.4G W2006-02-05-14-24-54 pp6/250 U,D,D 639M W2006-02-05-15-23-48 pp6/250 U,D,D ************************************************************************** feb09: (crew: Fagerstrom,Snider,Wechsler,Binod) Total data: 2.0 GB Alg/Pulse Antennas Notes 152M W2006-02-09-21-56-33 pp6/250 U,D,D 38M W2006-02-09-23-02-05 pp6/250 U,D,D 229M W2006-02-09-23-04-48 pp8/250 U,S,D,D 458M W2006-02-09-23-11-04 pp6/250 U,D,D 41M W2006-02-09-23-29-56 pp6/250 U,D,D 347M W2006-02-09-23-32-57 pp8/250 U,S,D,D 789M W2006-02-09-23-42-32 pp6/250 U,D,D h-noise spikes ************************************************************************** ................................................................................ Terminology and other notes: Terminology used to acknowledge data quality for each data file reported under Data file indormation: 1) SPIKES are defined as short lasting (less than a few secs), large excursions in positive or negative direction (higher than 2-3 dB). 2) ELEVATED NOISE (including short spikes) is defined as occasional change in the mean noise that exceeds 2-3 dB and lasts from fraction of a second to more than a minute. It is usually associated with ground hits and/or multi-trip echoes. It is observed for side looking mode only. 3) NOISE JUMPS/SPIKES (up to 10-20 sec). Probably some sort of short interference not necessarily in both channels and in some cases associated with the mirror position change or A/C radio communications at freqs close to 120MHz 3) NOISE DRIFT is up to 2dB slow drift in the noise channel; likely due to drift in the receivers gain. Usually it does not exceed 0.5 dB. 4) BAD DATA refer to corrupted data or improbable data behavior. 5) DATA SHIFT means that all data channels are shifted one range gate to the right for one or both of the DSPs. 6) DATA GAPS: gaps between profiles exceeding several times the average time interval between profiles 7) TIME STAMP ERROR: known fixed shift in the time stamps. 8) TIME JUMPS: sync problem in the time which results in time stamps jumps including negative jumps 9) DATA DISCONTINUITY: unexpected jumps in reflectivity occurring thru all range gates from one profile to another. 10) V/H-MISSING or V/H severely attenuated reffer to unidentified problem causing severe attanuation or lack of signal from a target Other Notes: * WCR data acquisition system (DAQ) records time stamps from the vxi IRIG card which is slaved to the master KingAir data system IRIG card. The recorded time stamps are GPS time (currently 14 sec ahead of UTC). * The zero range gate, when at 75 m, is contaminated with the transmitter pulse leakage which appears at levels as high as -35 dBm@500ns (+15 dBZ). On the other hand very stong returns at 0 and 1st range gates are slightly undervalued (1 dB or less) due to receiver protection switches still residually closed. This range is in the antenna far field for the SideUp (12") antenna. Far fields for the 18" and 15" down antennas are 132 m and 91 m, respectively. Thus for the bigger antennas the first few range gates may have larger calibration errors. * When in side looking mode and maximum unambiguous range of 7.5 km, the data can be contaminated from second trip echoes, mostly from surface. Caution should be exercised when analyzing side looks. * Average DSP jumps (data jumps between two consecutive profiles due to data acquisition DSP) are mostly near zero for low power returns but frequently high power return (as indicated by the leak) exhibit jumps as high as 1-2 dB and thus averaging at least two profiles is recommended to reduce calibration errors.