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Published byCollin Barton Modified over 9 years ago
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Dual-Frequency Precipitation Radar Status- 5/22/14 Sidelobes surface return seen in sidelobes at both nadir incidence and off-nadir in Ku data; not evident in Ka data. equivalent rain rates ~ 1-2 mm/h phase-shifter experiments have been performed 4/8, 4/14, and recently, to try to reshape antenna response pattern. NASA and NICT/JAXA performing sidelobe power subtraction based upon histograms of sidelobe power; NASA indexing correction to observed o. satellite pitch-angle experiments for aiming the antenna slightly off-nadir (through 4 o ) were inconclusive– no obvious benefit for reducing sidelobes. Surface Return saturation of Ku o observations due to attenuator setting; attenuator is now set at -12 dB. off-nadir DPR-Ku surface return is showing +1 dB bias relative to TRMM PR. see fluctuations of so due to vertical offset of surface gate with respect to the true surface ~ 1 dB.
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Dual-Frequency Precipitation Radar Status- 5/22/14 Ku/Ka Roll correction for Ku/Ka roll bias ~ 0.1 deg from star trackers implemented. Calibration DPR reflectivity calibration is now about -0.5 dB lower at Ku-band and -0.1 dB lower at Ka band than original calibration.
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Dotted line : anglebin all & rangebin all Narrow solid line : Nadir & rangebin all Thick solid line : Nadir & surface Angle bin (0start) count Count (left axis) / occurrence ratio (right axis) of saturated L1A echoCount for each angle bins. Occurrence ratio of saturated L1A echoCount against all foot prints Histogram of L1A echoCount (selected) [top] Occurrence ratio of L1A echoCount saturation [bottom] RxATT= 6dB RxATT= 9dB 3 anglebin all Nadir Nadir & surface rangebin all surface RxATT= 12dB L1A count 0255[count] 2226 Count of saturated L1A echoCount over Ocean at surface ( blue thick solid line) shows a constant decrease with RxAtt increase. 1.1x10^(-4) % at RxAtt=6dB, 0.7x10^(-4) % at RxAtt=9dB, 0.4x10^(-4)% at RxAtt=12dB. Some of saturated L1A echoCount was saved at higher RxAtt. Natural shape of L1A echoCount around saturated level (255). Unnatural jumping of L1A echoCount around saturated level (255). 2x10^-4 % 1.1x10^(-4) % 0.7x10^(-4) % 0.4x10^(-4) % from Noaufumi Yoshida
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Aside: Sigma0 Measured and BinEchoPeak Moving away from Equator. Surface getting farther surface Gate -1 Gate +1 Hump shape with max when surface is near center of gate. Peak to trough maybe >1dB? Impact to spatial reference? Number of scans with constant gate gets smaller. BinEchoPeak from John Kwiatkowski
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Ku/Ka Roll Ku mean: ~0.181deg. Ka mean: ~0.098deg. Project has determined Star Trackers have a +0.13deg Across Track Error (Roll). Will upload fix this Friday or Monday. Should see measured Roll bias decrease. GMI XCAL team indicates temp bias. Maneuver Spurious estimates of roll > 3-4 degrees. Results from JAXA ARC calibrations support this? PPS will reprocess with knowledge of this bias to correct older data. When: TBD. from John Kwiatkowski
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Ku/Ka Roll Trends V01E Star Tracker Update ~ -0.02deg Phase code Tx OFF ? Scanning Flipped Each point is mean roll in orbit. Assume that scan is symmetric. Ray vectors for Ku/Ka have: Ku: 0.01deg. Ka: -0.03deg. bias. No change in Ray Vectors for new phase codes yet (V01E). Will rerun with V01F. Ku: ~0.055deg Ka: ~ -0.07deg Phase code, scan direction OK.
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DPR L1 update results and future plan May 22, 2014 Ku echoPower Diff KaMS echoPower DiffKaHS echoPower Diff Ku@01E [dBm]KaMS@01E [dBm]KaHS@01E [dBm] 01F - 01E [dB] 1.0 1.0 1.0 01F - 01E [dB] Ku@01F – Ku@01E ~ -0.5dB KaMS@01F – KaMS@01E ~ -0.1dB KaMS@01F – KaMS@01E ~ -0.1dB The ‘01F’ product is the latest version and the ’01E’ product is previous version. The echo power decrease about 0.5 dB@Ku and 0.1dB@Ka compared with previous version. from Takuji Kubota
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DPR L1 update results and future plan < Update Schedule > LaunchL+1L+2L+3L+4L+5L+6 Initial C/O Nominal operation Limited Release(1) 4/15/16/17/18/19/1 Limited Release(2) 4/2TBD Public Release TBD DPR L1 FCIF-LUT Receiver gain offset DPR L2 ◆ (◆) 01E01F 5/20 ◆ 7/Early 02A (TBD) JPST-DPR/L2 01D ◆ 5/11: module deadline for JPST 5/12-25: integration and reprocessing 2/28 5/26 -6/6: analysis 6/6-16: Corresponding to JPST comments ◆ 6/30: module deadline for data release JPST-DPR/L1(TBD) JPST 7/1-14: integration and reprocessing 7/15 -8/3: analysis Ref. 'schedule_apr2014b.pptx‘ in previous L2 telecon JAXA will decide whether to add the gain offset or not by the early in July. The final calibration factor will be decided by the end of July. May 22, 2014 (◆) from Takuji Kubota
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PPS Status TKIO 3.60.2 is out. – No changes to DPR formats. GeoTK – New code handles knowledge of Star Tracker Bias, incorporated this reprocessing cycle. DPR – Starting ingest of 1BKu/Ka from JAXA (currently V01F data). – New Ku and Ka codes will be used with V01F data. 2AKu: 20140519 – PPS confirm seg. Fault orbit: 156. (Fix found Uwatoko-san!!) 2AKa: 20140519 2ADPR: 2014521 – Should start reprocessing on Thursday 5/22. Combined – Bill has some test orbits of input data. – PPS will run new code asap. GMI/Partner – GMI is now V02A – Reprocessing started on 5/20/2014.
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