WAICO 1 Feb - 31 Mar 2008 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: * 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 raw data is archived on a disk array in the UW DAS and a mass storage at NCAR. Quicklooks, dataquality, and calibration data are also archived. 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. They may be protected with a password. Contact the PI for access. ................................................................................ WCR configuration: WCR is installed on UWKA with 3-antenna configuration: Antenna 1 2,4 and no polarization capability. Antenna ports are: Ant1 (up) - H1, Ant2 (near nadir) - V2, Ant4 (down-aft) - H2; H/V stands for the receiver used (there are 2 receivers). Cross-channels (HXVX and VXHX channels) have no meaning for this configuration. ................................................................................ Radar Status/Problems * On March 1, the transmitter modulator failed (Fault 1 resulting from excessive body current). It was sent for a repair to ProSensing, Inc. A FET voltage regulator (in the high-voltage oil housing) failed due to local overheating. It was concluded that the possible reason for the overheating is the reduced amount of oil in the newly redesigned high-voltage cicuits oil housing. It was replaced and an additional heat sink was installed. The repaired unit is expected by the end of March. The second half of the field campaign is postponed to early 2009. ______ Jan 30 = few time glitches in one file ______ Feb 09 = J.French reported Fault 1 at the end of the flight. The tube and the modulator temperatures were below 100F. There was strong turbulence at the time of the fault. The radar was shut down without checking for a fault recovery. ______ Feb 14 = J.French reported Fault 1 at the end of the flight. Nothing unusual to be considered as a cause. ______ Feb 16 = J.French reported very low values for the Tx monitor (as low as 8 mV) The tests suggest that the W-band detector is not working well and the output pulse from it is very unstable. It looks like that the performance of the detector deteriorates with time. I could not see any effect on the received signal and thus it seems that the Tx is working fine. The possible problem with the detector has no effect on the performance of the transmitter and the quality of the collected data. = Time on tigger was wrong by about 7 hours. This caused wrong naming of the WCR files ______ Feb 23 = Installed a different W-band detector for testing. L.Oolman reported typically looking shape for the detected pulse through out the flight with a stable peak voltage. However see the next note: = Found some consecutive profiles (sometimes just one) with appreciable return above mean noise while the surounding profiles showed reasonably strong returns. This happens for all transmitted pulses (H1,V2 and H2). It is also in the even and odd profiles (no VXI DSP ping-pong problem). It affects all range gates including the leak gate but does not affect the noise. Thus it appears that the problem does not originate from the reciever IF unit and it is not likely to be caused by the VXI data system. The possible hardware components that may cause the problem are: the radar control board (in RF), the tube, the modulator, the curculator network, other components in the RF. Problem with the tube and/or the modulator should also affect the Scope Tx monitor peak voltage and pulse. ______ Feb 23 = Did not see any attenuated profiles in the data. L.Oolman reported no noticed dropped signals on the cpas display nor any issues with the scope Tx monitor peak voltage or pulse shape. ______ Mar 01 = J.French reported unrecoverable transmitter Fault 1 after 1-1.5 hours of flying. No any special circumstances were observed. The ambient temperature, Tx monitor peak voltage or pulse shape were all normal (to the extent they were observed). There was no siginificant turbulence. ... ............................................................................. Calibration notes: **************************************************************************** Power Calibration: * Calibration constants for this experiment as of 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@ 250ns Ant. 2 (nadir), VVcal2 = 50.5@ 250ns Ant. 4 (down-aft), HHcal2 = 55.5@ 250ns Notes: 1) Calibration constant precision over the whole dynamic range (no less than 70 dB) is about +-1. dB for both receivers 2) The absolute accuracy of the calibration constant for the nadir antenna is estimated to be around +-2.5 dB (based on the overall variability of the calibration constant from CR measurements 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. 3) 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 the quick look images: Ant. 1 (side/up), calHH1 = 49.5@ 250ns Ant. 2 (nadir), calVV2 = 50.5@ 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., -0.9986295 Ant. 1 (side): -0.0125, 0.99992, 0.00296 Ant. 2 (nadir): -0.0544, 0.005937, 0.99850 Ant. 4 (down-fore): 0.439959, 0.0131354, 0.897861 **************************************************************************** ................................................................................ WCR Data File Information: ************************************************************************** jan30: Test Flight Total data: 786 MB Alg Pulse Ants Notes 46M W2008-01-30-17-18-46 fft,250, U on the ground 3.1M W2008-01-30-17-21-45 spp,250, U on the ground 251M W2008-01-30-17-50-09 pp6,250, U,D,D 191M W2008-01-30-18-07-36 pp6,250, S,D,D hnoise spikes 45deg bank, rel.calib: 18:13-18:16 296M W2008-01-30-18-21-15 pp6,250, U,D,D 6 2-s time glitches: 28800-30895 ************************************************************************** feb05: Test Flight Total data: 812 MB Alg Pulse Ants Notes 11M W2008-02-05-17-25-17 pp6,250, S,D,D 181M W2008-02-05-17-26-08 pp6,250, S,D,D beamcal 3000ft AGL,hnoise spikes 192M W2008-02-05-17-44-53 pp6,250, S,D,D beamcal 10000ft AGL,hnoise spikes 428M W2008-02-05-18-05-17 pp6,250, S,D,D beamcal 17000ft AGL,hnoise spikes ************************************************************************** feb06: Total data: 2.5 GB Alg Pulse Ants Notes 366M W2008-02-06-17-09-28 pp6,250, U,D,D 348M W2008-02-06-17-33-49 pp6,250, U,D,D 533M W2008-02-06-17-56-57 pp6,250, U,D,D 240M W2008-02-06-18-32-24 pp6,250, U,D,D 456M W2008-02-06-18-48-24 pp6,250, U,D,D 521M W2008-02-06-19-18-45 pp6,250, U,D,D ************************************************************************** feb08: Total data: 116 MB Alg/Pulse Antennas Notes 116M W2008-02-08-20-24-07 pp6,250, U,D,D ************************************************************************** feb09: Total data: 2.5 GB Alg Pulse Ants Notes 384M W2008-02-09-16-59-35 pp6,250, U,D,D 466M W2008-02-09-17-25-07 pp6,250, U,D,D h/vnoise spikes 589M W2008-02-09-17-56-09 pp6,250, U,D,D 428M W2008-02-09-18-35-16 pp6,250, U,D,D 398M W2008-02-09-19-03-42 pp6,250, U,D,D 261M W2008-02-09-19-30-10 pp6,250, U,D,D Fault1 from 194709-end ************************************************************************** feb14: Total data: 2.0 GB Alg Pulse Ants Notes 467M W2008-02-14-15-54-45 pp6,250, U,D,D 430M W2008-02-14-16-25-47 pp6,250, U,D,D 476M W2008-02-14-16-54-23 pp6,250, U,D,D 454M W2008-02-14-17-26-05 pp6,250, U,D,D h/vnoise spikes 205M W2008-02-14-17-56-15 pp6,250, U,D,D Fault 1 after 18:08:06-end(09:45) ************************************************************************** feb16: Total data: 2.6 GB Alg Pulse Ants Notes 498M W2008-02-16-09-17-57 pp6,250, U,D,D time glitch (32705-32784) 278M W2008-02-16-09-51-05 pp6,250, U,D,D hnoise spikes 590M W2008-02-16-10-09-34 pp6,250, U,D,D hnoise spikes 586M W2008-02-16-10-48-49 pp6,250, U,D,D hnoise spikes 231M W2008-02-16-11-27-46 pp6,250, U,D,D hnoise spikes 214M W2008-02-16-11-43-51 fft,250, U 253M W2008-02-16-11-56-32 pp6,250, U,D,D ************************************************************************** feb20: Total data: 2.3 GB Alg Pulse Ants Notes 245M W2008-02-20-20-11-47 pp6,250, U,D,D 285M W2008-02-20-20-28-31 pp6,250, U,D,D 286M W2008-02-20-20-47-25 pp6,250, U,D,D 317M W2008-02-20-21-06-25 pp6,250, U,D,D 412M W2008-02-20-21-27-30 pp6,250, U,D,D hnoise spikes 442M W2008-02-20-21-54-56 pp6,250, U,D,D 330M W2008-02-20-22-24-21 pp6,250, U,D,D ************************************************************************** feb23: Total data: 2.9 GB Alg Pulse Ants Notes 179M W2008-02-23-17-05-16 pp6,250, U,D,D 378M W2008-02-23-17-22-55 pp6,250, U,D,D 416M W2008-02-23-17-48-02 pp6,250, U,D,D 417M W2008-02-23-18-15-42 pp6,250, U,D,D hnoise spikes 361M W2008-02-23-18-43-27 pp6,250, U,D,D h/vnoise spikes 528M W2008-02-23-19-07-28 pp6,250, U,D,D V2/H2 missing signals 19:13-19:16 419M W2008-02-23-19-42-33 pp6,250, U,D,D 242M W2008-02-23-20-16-24 pp6,250, U,D,D V2/H2 missing signals 20:31:20-20:32:20 ************************************************************************** feb26: Total data: 708 MB Alg Pulse Ants Notes 167M W2008-02-26-21-01-40 pp6,250, U,D,D 71M W2008-02-26-21-13-29 spp,250, U 470M W2008-02-26-21-38-54 pp6,250, U,D,D ************************************************************************** feb27: Total data: 3.8 GB Alg Pulse Ants Notes 232M W2008-02-27-15-57-18 pp6,250, U,D,D 83M W2008-02-27-16-13-05 pp6,250, U 489M W2008-02-27-16-41-52 pp6,250, U,D,D 237M W2008-02-27-17-14-24 pp6,250, U,D,D 274M W2008-02-27-17-30-18 pp6,250, U,D,D 98M W2008-02-27-17-48-30 pp6,250, U,D,D 506M W2008-02-27-17-55-02 pp6,250, U,D,D 524M W2008-02-27-18-28-40 pp6,250, U,D,D h/vnoise spikes 178M W2008-02-27-19-03-33 pp6,250, U,D,D h/vnoise spikes 412M W2008-02-27-19-15-21 pp6,250, U,D,D h/vnoise spikes, 2nd trip ground 469M W2008-02-27-19-42-44 pp6,250, U,D,D hnoise spikes 355M W2008-02-27-20-13-55 pp6,250, U,D,D hnoise spikes ************************************************************************** feb28: Total data: 2.3 GB Alg Pulse Ants Notes 473M W2008-02-28-20-57-15 pp6,250, U,D,D 421M W2008-02-28-21-28-43 pp6,250, U,D,D 437M W2008-02-28-21-56-41 pp6,250, U,D,D 422M W2008-02-28-22-25-42 pp6,250, U,D,D 428M W2008-02-28-22-53-46 pp6,250, U,D,D 122M W2008-02-28-23-22-11 pp6,250, U,D,D ************************************************************************** feb28: Total data: 431 MB Alg Pulse Ants Notes 378M W2008-03-01-20-53-48 pp6,250, U,D,D 36M W2008-03-01-21-19-22 spp,250, U 18M W2008-03-01-21-32-04 pp4,250, U,D Fault 1 after 21:33:25(prof 2466) ............................................................................. Terminology and other notes: Other Notes: * WCR data acquisition system (DAQ) records time stamps from the vxi IRIG card which is slaved to the master C130 data system time server. The recorded time stamps are UTC time. * 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 far field for the two 12" 'down-pointing' antennas. Far fields for the 15" 'down-slant' antenna is 91 m and for the 18" nadir antenna it is 132 m. Thus for the bigger antennas the first few range gates may have larger calibration errors. * When maximum unambiguous range is 7.5 km, the data can be contaminated from second trip echoes, mostly from surface. * Average DSP jumps (data jumps between two consecutive profiles due to data acquisition DSPs) 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. 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/GLITCHES: 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