Airborne Cloud Radar Experiment (HICU02), 16 July -05 August 2002 Wyoming Cloud Radar Data Status Report Content: WCR configuration Calibration Notes Quick Looks Terminology General Notes Flights Information WCR configuration: WCR was installed on UWKA with a dual-antenna configuration: Antenna 1,2,3 and 4; modes 1,3,4,5,6 and 7, http://www-das.uwyo.edu/wcr/mmradar.modes.html; H-receiver (channel) is associated with Ant. 1 and 4, V-receiver (channel) is associated with Ant 2 and 3; the transmission is linearly polarized 250/500 ns pulses; Ant.3 and Ant.1, while in side-looking direction, transmit H-polarized pulses. Cross-channels (HV and VH channels) have no meaning for this configuration. Ant. 1 uses UWKA radar mirror wing to direct the radar beam side or up. Ant. 2 is permanently directed near nadir. Ant. 3 is permanently directed about 30 deg side-fore and Ant. 4 is pointed down-fore (~30 deg down forward). Only 2active antennas can be used at any given time. Ant. 1 and 4, attached to H-channel, and Ant. 2 and 3, attached to V-channel are switched manually using two wave guide switches. Sitches change events are not recorded electronically. 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. If the KA* file is not present only UP or SIDE position was used during the flight. Calibration notes: * Final Calibration constants for this experiment. Calibration constants (250 ns pulse, 5 MHz IF filter, dynamic range > 70 dB): Ant. 1, HHcal = 49.0 Ant. 2, VVcal = 50.0 Ant. 3, VVcal = Not calibrated (to be used for Doppler velocities only) Ant. 4, HHcal = Not calibrated (to be used for Doppler velocities only) Cross-channel Isolation > 50 dB (not important since cross-channels have no meaning in this 2-antenna configuration) Antenna Coupling Separation: antenna coupling not detected (OMT not installed) Quick Looks: Quick look images of co-pol reflectivity for all the flights are stored in their corresponding directories(mmmDD) as pdf files. Terminology: Terminology used to acknowledge data quality for each data file reported under Flights 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 of up to 2 sec. Noticed only in the beginning of the first file for less than 10-15 min. 9) DATA DISCONTINUITY: unexpected jumps in reflectivity occurring thru all range gates from one profile to another. General Notes: * WCR raw data is archived and available on Exabyte tapes. * 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 13 sec ahead of UTC). * Occasionally, large time gaps (data gaps) exist. For example data file W2002-07-18-18-11-24 reports average time interval between the profiles as about 25 ms, but there are occurencies of 0.2-0.3s intervals. The reason for this is not clearly identified at this point. * The zero range gate, when at 75 m, is contaminated with the transmitter pulse leakage for intensities below -45 dBm (~ 4 dBZ). On the other hand very stong returns at this range 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 significant calibration errors * When in side looking mode the noise channels, as well as some of the data range gates, are occasionally contaminated from second trip echoes, mostly from ground. 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. * Mean(std) noise levels (corresponding noise pulses averaged): 250ns: hnoise/vnoise ~ -63/-66 dBm (76/79 dB) 500ns: hnoise/vnoise ~ -68/-70 dBm (80/82 dB) * HH Tx leak received is consistently larger than VV Tx leak by 2 to 15 dB * Problems encountered during the experiment July 18: about +20,000s time jump around 16:55:20; lasted about 9-10 s during which time stamps did not advance correctly July 26: H-ch not working properly. At least 10 dB or more loss in sensitivity. July 27: During test measurements the received signal on H-ch was lost completely. The reason identified was malfunction of the driver (B) that controls a pair of protector circulators on the H-side of the circulator network. It was also identified that driver C (controlling protrctor circulators on the V side) is not working as the specs suggest, acknowledged by Andy Pazmany, therefore it is not swappable with B. The rest of the flights used V-ch only (down or side-fore antennae) Flights Information: -------------------------------------------------------------------------- Flight date/ File(size name) WCR mode Status ************************************************************************** jul18: ( 2.5 hours, Cooksey, Kelly,Haimov,Snider) Total data: 1.3 GB Alg Antennas Notes 349M W2002-07-18-16-21-57, pp4, up,down 46M W2002-07-18-16-53-53, pp4, side/up,side, time glitch (165520-165529) 33M W2002-07-18-16-57-03, pp4, down,down 38M W2002-07-18-16-59-17, pp4, side/up,side, elevated noise 39M W2002-07-18-17-01-48, pp4, up,down 34M W2002-07-18-17-06-01, pp4, side,side, 0.8s data gap 182M W2002-07-18-17-09-09, pp4, down,down 31M W2002-07-18-17-21-54, pp4, down,down 28M W2002-07-18-17-24-12, pp4, side,side, 500ns 28M W2002-07-18-17-28-25, pp4, side,side, 500ns 324M W2002-07-18-17-40-27, pp4, up,down, 17:50 rain, 0.8s data gap 129M W2002-07-18-18-11-24, pp4, side,side, ground return w/o and w/ yaw ************************************************************************** jul19: ( 2.5 hours, Cooksey, Kelly,Haimov,Snider) Total data: 537 MB Alg Antennas Notes 37M W2002-07-19-16-34-26, pp4, up,down 57M W2002-07-19-16-47-33, pp4, up,down 41M W2002-07-19-16-56-56, pp4, up,down 45M W2002-07-19-17-05-58, pp4, side,side, 500ns 44M W2002-07-19-17-08-57, pp4, up,down 11M W2002-07-19-17-13-52, pp4, side,side, 500ns 48M W2002-07-19-17-26-11, pp4, up,down 18M W2002-07-19-17-33-38, pp4, up,down 22M W2002-07-19-17-36-01, pp4, side,side, 500ns 21M W2002-07-19-17-41-57, pp4, side,side, 500ns 192M W2002-07-19-17-53-36, pp4, up,down ************************************************************************** jul20: ( 3.2 hours, Cooksey, Kelly,Haimov,Snider) Total data: 305 MB Alg Antennas Notes 16M W2002-07-20-16-40-09, pp4, up,down 14M W2002-07-20-16-42-15, pp4, side,side, 250ns 32M W2002-07-20-16-43-58, pp4, side,side, 500ns 13M W2002-07-20-16-54-10, pp4, up,down 12M W2002-07-20-16-55-58, pp4, side,side, 500ns 17M W2002-07-20-16-58-16, pp4, up,down 13M W2002-07-20-17-00-33, pp4, up,down 30M W2002-07-20-17-02-42, pp4, side,side, 500ns 38M W2002-07-20-17-07-09, pp4, up,down 11M W2002-07-20-17-15-18, pp4, down,down 11M W2002-07-20-17-16-45, pp4, side,side, 500ns 16M W2002-07-20-17-18-41, pp4, up,down 75M W2002-07-20-17-27-35, spp, up ************************************************************************** jul25_ferry: ( 2.5 hours, Sand, Haimov,Glover,Snider) Total data: 898 MB Alg Antennas Notes 170M W2002-07-25-20-20-44, pp4, down,down; flew below cloud base till 20:23:37,precip.,3-s time jumps 67M W2002-07-25-20-30-11, pp4, side,up, 3-s time jumps this was intended to be side-side but apparently the mirror was not switched to side for the side/up antenna 16M W2002-07-25-20-37-25, pp4, up,down, one 3-s time jump 218M W2002-07-25-20-39-36, pp4, up,down, 3-s time jumps 321M W2002-07-25-20-52-28, pp4, down,down, 3-s time jumps 102M W2002-07-25-21-06-23, fft, nadir ************************************************************************** jul26: ( 2.0 hours, Sand, Kelly,Haimov,Snider) H-ch was considerably weaker through the whole flight ????? TFP status bits were 006-007 first 15 min, then 002-000 Total data: 197 MB Alg Antennas Notes 27M W2002-07-26-16-38-04, pp4, up,down 68M W2002-07-26-16-44-21, pp4, up,down, 500ns, 8 noise samples 55M W2002-07-26-17-10-43, pp4, down,down 22M W2002-07-26-17-14-23, pp4, down,down, 500ns 14M W2002-07-26-17-19-49, pp4, down,down, 500ns 10M W2002-07-26-17-23-17, pp4, side,side, 500ns ************************************************************************** jul30: ( 1.3 hours, Sand, Snider,Glover,Petters) Total data: 154 MB Alg Antennas Notes 143M W2002-07-30-16-36-13, spp, nadir, 225ns 5.0M W2002-07-30-17-28-14, spp, side-fore, 225ns, ground return 6.4M W2002-07-30-17-30-08, spp, side-fore, 225ns, ground return ************************************************************************** aug02: ( 2.8 hours, Sand, Snider,Glover,Petters) Total data: 295 MB Alg Antennas Notes 131M W2002-08-02-17-12-49, spp, nadir, 225ns 138M W2002-08-02-17-54-24, spp, nadir, 525ns, strong disturbances in all channels (18:34,19:11,19:17, 19:18), elevated noise 25M W2002-08-02-19-34-41, spp, nadir, 225ns ************************************************************************** aug03: ( 3.5 hours, Sand, Snider,Glover,Petters) Total data: 413 MB Alg Antennas Notes 138M W2002-08-03-16-26-35, spp, nadir, 225ns 55M W2002-08-03-17-10-19, spp, nadir, 525ns 218M W2002-08-03-18-03-30, spp, nadir, 225ns ************************************************************************** aug03: ( 2.8 hours, Sand, Snider,Glover,Petters) Total data: 454 MB Alg Antennas Notes 376M W2002-08-04-20-33-00, spp, nadir, 225ns 15M W2002-08-04-22-29-50, spp, nadir, 525ns 62M W2002-08-04-22-44-55, spp, nadir, 225ns ************************************************************************** aug05_ferry: 2.0 hours, Sand, Petters,Haimov,Snider) Total data: 156 MB Alg Antennas Notes 5.7M W2002-08-05-17-28-50, spp, nadir, 525ns 7.8M W2002-08-05-17-31-41, spp, nadir, 525ns 14M W2002-08-05-17-36-10, spp, nadir, 525ns 16M W2002-08-05-17-43-35, spp, nadir, 225ns 57M W2002-08-05-17-56-46, spp, nadir, 525ns 54M W2002-08-05-18-28-03, spp, nadir, 525ns **************************************************************************