Lim IGARSS2011 Reduced.ppt


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  • 4 distributed thermisors Ambient targets maximum rate of change ~20C over 3 hours, 7C per hour Heated targets very stable Improvements with dithering of the dac
  • Approx 10C separation in the targets Will also automatically flag if there is a ‘broken’ channel – connection loose, thermal breaks, motor scanning, other mechanical issues
  • No discernable difference when Using the Hot or Ambient Counts. Future processing would take a better average of it.
  • The gain now actually represents the physical change in the system Receiver temperature does not change on small time scales
  • Instantaneous reaction to changes in the system, represented by the change in the counts. Note the thickness in the trace of the ‘smoothed’ gain Actually in the receiver
  • Even in failure situations, the calibration is robust and does not incorrectly flag data
  • Noise statistics, STD vs percentage Imperative that the flagged pixels are actually what ‘marginal’ and is not flagging good data
  • Noise statistics, STD vs percentage Imperative that the flagged pixels are actually what ‘marginal’ and is not flagging good data
  • Integrated Multispectral Atmospheric Sounders (IMAS) – NASA Code Y Technology Development Funds JPL, TRW, UMASS develop InP MMICs 55/118 downconverter units CAMEX-4 Convection And Moisture Experiment (Jacksonville, Florida) TCSP Tropical Cloud Systems and Processes (Costa Rica) NAMMA NASA African Monsoon Multidisciplinary Analyses (Cape Verde)
  • 4 distributed thermisors Ambient targets maximum rate of change ~20C over 3 hours, 7C per hour Heated targets very stable Improvements with dithering of the dac
  • 0.52 dwell time on each target Lines indicated the maximum time from the other target and the maximum time from a single ended calibration
  • Lim IGARSS2011 Reduced.ppt

    1. 1. CALIBRATION AND PERFORMANCE OF THE HAMSR INSTRUMENT DURING THE NASA GRIP CAMPAIGN Boon Lim*, Shannon Brown, Richard Denning, Pekka Kangaslahti, Bjorn Lambrigtsen, Jordan Tanabe, and Alan Tanner Jet Propulsion Laboratory *Contact :
    2. 2. Outline <ul><li>HAMSR Overview </li></ul><ul><li>Genesis and Rapid Intensification Processes (GRIP) Campaign </li></ul><ul><li>Data System </li></ul><ul><li>Thermal Environment </li></ul><ul><li>External target – Stability, Gradients, Reflection </li></ul><ul><li>Nominal Calibration (V0) </li></ul><ul><li>Receiver Temperature Calibration (V1) </li></ul><ul><li>Calibration Comparison (V0 vs V1) </li></ul><ul><li>HAMSR Performance </li></ul><ul><li>Summary </li></ul>7/29/2011 IGARSS 2011
    3. 3. HAMSR Overview <ul><li>High Altitude MMIC Sounding Radiometer (HAMSR) </li></ul><ul><li>3 Sounding Bands (55, 118 and 183 GHz) </li></ul><ul><li>25 total channels </li></ul><ul><li>Oxygen and Water Vapor Bands for Profiling </li></ul><ul><li>Cross-Track Scanner with Ambient/Hot External Calibration Targets </li></ul><ul><li>Product of ESTO (IIP, ACT and AITT) </li></ul><ul><ul><li>Entering 15 th Year </li></ul></ul><ul><ul><li>Participated in 5 Campaigns </li></ul></ul><ul><ul><li>Integrated on 3 Aircraft </li></ul></ul>7/29/2011 IGARSS 2011
    4. 4. GRIP Campaign <ul><li>Genesis and Rapid Intensification Processes Campaign </li></ul><ul><ul><li>5 th Coordinated Hurricane Field Campaign Since 1998 </li></ul></ul><ul><ul><li>NOAA, NSF and the AF </li></ul></ul><ul><li>From August to September 2010 </li></ul><ul><li>DC-8 (9), Global Hawk (4) and WB-57 (2) </li></ul><ul><ul><li>Approximately 300 flight hours </li></ul></ul><ul><li>Hurricane Frank (Pacific), Tropical Storm Matthew (Atlantic), Hurricanes Earl and AL-92/Karl (Atlantic) </li></ul><ul><ul><li>Global Hawk Stationed at Dryden </li></ul></ul><ul><ul><li>Over 120 Flight Hours for the Global Hawk </li></ul></ul><ul><ul><li>20 Eye Overpasses Hurricane Karl (~13 Hours) </li></ul></ul><ul><ul><li>Typical flight duration 24 Hours </li></ul></ul>7/29/2011 IGARSS 2011
    5. 5. GRIP Flights 7/29/2011 IGARSS 2011 Frank 08/28/2010 Earl 09/02/2010 Matthew 09/23/2010 AL92 09/12/2010 Karl 09/16/2010
    6. 6. HAMSR Imagery During GRIP Hurricane Earl 2010
    7. 7. Hurricane Matthew Platform Report – Scott Braun 7/29/2011 IGARSS 2011
    8. 8. HAMSR GRIP Ground Data System HAMSR ground data processor netCDF L1B files JPL Hurricane Portal HAMSR website quick look images RTMM Commanding Data downlink GHOC
    9. 9. HAMSR software upgraded after GRIP to provide real-time imagery over Iridium Successfully tested during 2011 WISPAR campaign HAMSR RTMM Display for GRIP
    10. 10. Thermal Environment <ul><li>HAMSR Sits in an Unpressurized Pod </li></ul><ul><li>RF Section is Thermally Insulated with Styrofoam </li></ul><ul><li>Temperature Controlled Heaters on the RF Plates </li></ul><ul><ul><li>Thermistors Available Across the Instrument </li></ul></ul><ul><ul><li>RF Components (RF/IF LNAs, Mixers), RF Plate Temperatures, Motor, Power Supply, Digital System, Computer, Etc </li></ul></ul><ul><li>Fans for Circulation of Air </li></ul><ul><ul><li>On Runway if Temperatures Exceed a Threshold </li></ul></ul><ul><li>At Flight Altitude (~17 km) </li></ul><ul><ul><li>Temperature Typically -15 0 C </li></ul></ul>7/29/2011 IGARSS 2011
    11. 11. WISPAR 2011- Thermal Environment 7/29/2011 IGARSS 2011
    12. 12. External Target - Stability <ul><li>Thermistors Embedded in Targets </li></ul><ul><li>Ambient Target Drifts Freely </li></ul><ul><ul><li>Rate of Change 6-7 o C/Hour </li></ul></ul><ul><li>Hot Target Held at ~68 o C </li></ul><ul><ul><li>Oscillation at 120 Second Period, 0.01K< </li></ul></ul>7/29/2011 IGARSS 2011
    13. 13. External Target - Gradients <ul><li>Gradients Across the Target Pixels </li></ul><ul><ul><li>Typically Monotonic </li></ul></ul><ul><ul><li>Magnitude Under 0.3K </li></ul></ul><ul><ul><li>Easily Mitigated with Averaging </li></ul></ul>7/29/2011 IGARSS 2011
    14. 14. External Target - Reflections <ul><li>Standing Waves Setup in the Middle of the Target </li></ul><ul><ul><li>Despite Low Return Loss Material (~35 dB) </li></ul></ul><ul><ul><li>Only in Several Frequencies </li></ul></ul><ul><ul><li>Remove Central Pixels </li></ul></ul>7/29/2011 IGARSS 2011
    15. 15. Initial Processing <ul><li>Moving Average of the Hot and Ambient Counts </li></ul><ul><ul><li>Period of the Heating Oscillation (~110 Seconds) </li></ul></ul><ul><li>Time ‘Shift’ in Ambient Counts </li></ul><ul><ul><li>Account for linear time drifts </li></ul></ul><ul><li>Calculate Per-Scan Gain </li></ul><ul><ul><li>Gain = (C Hot – C Amb )/(T Hot – T Amb ) [C/K] </li></ul></ul><ul><li>Flag Unusable Pixels (-2) </li></ul><ul><ul><li>Insufficient Separation of the Hot and Ambient Targets </li></ul></ul><ul><ul><li>Differential Temperatures on Targets, 5xNEDT </li></ul></ul><ul><ul><li>Differential Gain, Threshold (empirical) </li></ul></ul>7/29/2011 IGARSS 2011
    16. 16. Nominal Processing <ul><li>Moving Average of Gain </li></ul><ul><li>Calculate Antenna Temperature </li></ul><ul><ul><li>T A = (Ct – C Amb )/Gain + T Amb </li></ul></ul><ul><li>Standard Calibration Stratagy </li></ul><ul><li>Gain Drifts/Jumps Distributed in the Averaging </li></ul><ul><li>Incorrectly Processes ‘Good’ Data </li></ul>7/29/2011 IGARSS 2011
    17. 17. Receiver Temperature Calibration <ul><li>Calculate Receiver Temperature </li></ul><ul><ul><li>T Rx = C Amb /Gain - T Amb </li></ul></ul><ul><li>Smooth Receiver Temperature </li></ul><ul><li>Calculate Gain (from Hot Target) </li></ul><ul><ul><li>G Hot = C Hot /(T Rx +C Hot ) </li></ul></ul><ul><li>Calculate Gain (from Ambient Target) </li></ul><ul><ul><li>G Amb = C Amb /(T Rx +C Amb ) </li></ul></ul><ul><li>Average Gain </li></ul><ul><ul><li>Gain = (G Hot +G Amb )/2 </li></ul></ul><ul><li>Calculate Ta </li></ul><ul><ul><li>T A = (Ct – C Amb )/Gain + T Amb </li></ul></ul>7/29/2011 IGARSS 2011
    18. 18. Comparison – Gain Smoothing 7/29/2011 IGARSS 2011
    19. 19. Comparison – Spikes 7/29/2011 IGARSS 2011
    20. 20. Comparison – Robustness 7/29/2011 IGARSS 2011
    21. 21. Flag Marginal Pixels <ul><li>Pixels that Exhibit Larger than Expected Noise </li></ul><ul><ul><li>Temperature is Over 3.5x NEDT </li></ul></ul><ul><ul><li>Empirical Value for Each Channel </li></ul></ul><ul><ul><li>For End-Product Users </li></ul></ul>7/29/2011 IGARSS 2011
    22. 22. Marginal Pixels 7/29/2011 IGARSS 2011
    23. 23. Flag Marginal Pixels Second Check <ul><li>Receiver Temperature Calibration </li></ul><ul><li>Close to the Theoretical Values for Noise </li></ul>7/29/2011 IGARSS 2011
    24. 24. Instrument Performance <ul><li>As Derived from the Data </li></ul><ul><ul><li>Hurricane Karl </li></ul></ul><ul><li>55 GHz Performs the Poorest </li></ul><ul><ul><li>Legacy Hardware </li></ul></ul><ul><ul><li>Upgrade in Progress (~4dB) </li></ul></ul><ul><li>118 GHz and 183 GHz Upgraded During AITT </li></ul><ul><li>Performance is as Expected from the Receiver Temperatures </li></ul><ul><li>99.9% Up-Time </li></ul><ul><ul><li>1 Channel Dropped Out for 3 Hours </li></ul></ul>7/29/2011 IGARSS 2011
    25. 25. Summary <ul><li>External Targets Well Characterized </li></ul><ul><li>HAMSR Successfully Participated in GRIP Campaign </li></ul><ul><ul><li>Data System Utilized High Bandwidth Link (‘Real-Time’) </li></ul></ul><ul><ul><li>Utility was Immediate in Directing the GH Flight Path </li></ul></ul><ul><li>Calibration Methodology Relies on Stability of Receivers </li></ul><ul><ul><li>Front End LNAs vs Entire Gain Chain </li></ul></ul><ul><li>HAMSR Receivers as a System Perform to Measured Receiver Temperatures </li></ul><ul><li>WISPAR Campaign Had Coincident Dropsondes </li></ul><ul><ul><li>Absolute Calibration Comparison Pending </li></ul></ul><ul><li>Instrument calibration and characterization (Brown et al., TGRS, in press) </li></ul>7/29/2011 IGARSS 2011
    26. 26. Backup Slides <ul><li>HAMSR Timeline </li></ul><ul><li>HAMSR Block Diagram </li></ul><ul><li>External Target Construction </li></ul><ul><li>Pre-Flight Evaluation </li></ul><ul><li>Allan Variance LN2 Stare </li></ul><ul><li>GRIP – Agency Coordination </li></ul><ul><li>Danielle, Earl and Fiona </li></ul>7/29/2011 IGARSS 2011
    27. 27. HAMSR Timeline 7/29/2011 IGARSS 2010=1
    28. 28. HAMSR Block Diagram 7/29/2011 IGARSS 2011
    29. 29. External Target - Construction <ul><li>Pyramidal Blackbody Calibration Targets </li></ul><ul><ul><li>Ambient and ~68 0 C </li></ul></ul><ul><li>Commercial Product with -50dB Return Loss Spec </li></ul><ul><ul><li>Heavy Aluminium Coated with a Ferrite Loaded Epoxy Absorbing Material </li></ul></ul><ul><ul><li>16x12 cm Area, 4 cm Long Pyramids, 1 cm Apart at Tips </li></ul></ul><ul><li>4 Thermistors Embedded in Targets at the Tips </li></ul><ul><li>Insulated in Styrofoam </li></ul><ul><ul><li>~35dB Return Loss </li></ul></ul>7/29/2011 IGARSS 2011
    30. 30. Pre-Flight Evaluation – Scan Bias <ul><li>Within the field of view, minimal bias in the various channels </li></ul><ul><li>50 GHz channels: </li></ul><ul><ul><li>Bias < 0.5 K for -45 o < θ < 45 o </li></ul></ul><ul><li>118/183 GHz channels: </li></ul><ul><ul><li>Bias < 0.25 K for -45 o < θ < 45 o </li></ul></ul>7/29/2011 IGARSS 2011
    31. 31. Allan Variance LN2 Stare 7/29/2011 IGARSS 2011
    32. 32. GRIP – Agency Coordination 7/29/2011 IGARSS 2011
    33. 33. Danielle, Earl and Fiona 7/29/2011 IGARSS 2011