CoSMIR Performance during OLYMPEX - PowerPoint Presentation

Slide1

CoSMIR Performance during OLYMPEX

Rachael Kroodsmarachael.a.kroodsma@nasa.govUMD ESSIC / NASA GSFCOLYMPEX Workshop - Seattle, WAMarch 21-23, 2017

Kroodsma OLYMPEX Workshop

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Outline

Brief CoSMIR descriptionInstrument characteristicsImprovements since IPHEXPerformance during OLYMPEXData outagesIssues encounteredData AnalysisGeolocation

Comparisons with GMIData Description

Kroodsma OLYMPEX Workshop

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Instrument Characteristics

Kroodsma OLYMPEX Workshop3

Frequency (GHz)50.3

52.889.0

165.5

183.31±1

183.31±3

183.31±7

Polarization

H

H

V/H

V/HHHHSensitivity (K)0.420.420.40/0.300.80/0.450.530.430.41

Conical and cross-track scanning total power radiometerOff-nadir angle 49.2°Similar channels as GMI (high frequency)

Scan GeometryConical scanFootprint 1.3x1.9 km*Azimuth -60° to 60° (51 samples)3 seconds to complete scan

Cross track scanFootprint 0.8x0.8 km at nadir* Elevation -49.2° to 49.2° (51 samples)2 seconds to complete scan

*DC-8 cruising altitude of 11.8 kmSlide4

Scanning Geometry

Kroodsma OLYMPEX Workshop4

CoSMIR

scan pattern for one complete cycle where the azimuth rotates once and the elevation twice. Corresponding 89V counts shown for a flight.

CoSMIR

ground track for one cycle.

Aircraft ground speed 200 m/s and altitude 11.8 km.

Two conical and two

cross-track

scans are

alternately performed every cycle with

hot and cold target looks after each scan.

Flight Direction

Scan DirectionScan Direction

Conical 2HotCold

Crosstrack 1HotCold

Cold

Hot

Cold

Hot

Crosstrack

2

Conical 1Slide5

Improvements since IPHEX

Several modifications were made since the last campaign (IPHEX in 2014) to make CoSMIR more reliablePower system now has a custom board to improve instrument grounding and reduce noiseThermal system now uses chip heaters to better control temperature166 GHz receiver redesigned with newer technologyMechanical layout redesigned to make it more robust

Instrument tested in thermal chamber prior to flightDetected issue with motion control and fixed

Kroodsma OLYMPEX Workshop

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CoSMIR Performance During OLYMPEX

Overall, CoSMIR operated extremely well for most of the campaignTotal data collected: 72 hours, 8 minutesTotal data lost: approx. 4 hoursNominal operation: all channels operated for entire flight with CoSMIR in hybrid scan modeCross-track mode only: first three flights operated only in cross-track until azimuth scan was fixedHot target power supply: issues with power supply on plane caused computer outages and gain increases

Some flights lost 52 and/or 50 GHz channels part wayKroodsma OLYMPEX Workshop

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Kroodsma OLYMPEX Workshop

7Date (UTC)

CoSMIR

data collected

(UTC

)

GPM overpass

(

UTC)

CoSMIR

performance notes

11/5/2015

20:04-22:38--Nominal operation

Engineering test flight out of Palmdale, CA11/12/2015

16:09-22:1721:16Cross-track mode only11/13/2015

13:56-19:29--Cross-track mode

only

11/14/2015

17:13-23:17

21:06

Cross-track mode

only

11/18/2015

18:29-00:06

--

Nominal operation

11/23/2015

15:57-21:40

--

Nominal operation

11/24/2015

14:40-19:34

18:36

Hot target

power supply issue

11/25/2015

17:24-19:15

17:43

Hot target power supply issue

Lost 52

GHz channel after 18:20 due to

gain increase

12/1/2015

20:59-01:25

--

Hot

target power supply issue

Lost 52 GHz channel after

22:43

Lost 50 GHz channel after

00:15

12/3/2015

14:33-16:59

15:22

Hot target power supply issue

Lost 52 GHz channel after

16:05

12/4/2015

13:27-17:31

--

Nominal

operation

Fixed hot target power supply issue

12/5/2015

14:18-15:38

15:13

Lost 52 GHz channel after

15:08

Lost 50 GHz channel after

15:31

Lost connection with

archive computer

at 1

5:38

12/8/2015

14:08-16:33

17:44-19:24

14:11

Lost 52 GHz channel after 14:36.

Lost connection with

archive computer

at

16:33

Rebooted

successfully but hot

target temperature

not

recorded for the rest of the

flight

12/10/2015

14:58-15:55

16:34-19:18

--

Lost connection with

archive computer

at 15:55. Rebooted successfully but hot

target

temperature not recorded for the rest of the flight

12/12/2015

15:52-21:15

--

Nominal operation

12/13/2015

13:54-18:15

--

Nominal operation

12/18/2015

04:57-07:04

--

Nominal operation

12/19/2015

01:32-03:22

2:54

Nominal operationSlide8

Quicklook Plot Example 12/3/2015

Kroodsma OLYMPEX Workshop8Slide9

Some Pictures

Kroodsma OLYMPEX Workshop9

Credit: NASA

NASA DC-8

CoSMIR

Credit: NASA

Onboard operations

CoSMIR

mounted on DC-8

12/4/2015 flight pathsSlide10

Geolocation

Kroodsma OLYMPEX Workshop1089H TBs at coastlines look accurate

11/18 flight

11/25 flight

CoSMIR

has an azimuth mounting

offset. This offset was estimated and

confirmed

using Google Earth to plot TBs at coastlines.Slide11

GPM Overpass: Comparisons with GMI

Kroodsma OLYMPEX Workshop11

ChannelGMI

89.0 V/H166.0 V/H

183.31±3 V

183.31±7 V

CoSMIR

89.0 V/H

165.5 V/H

183.31±3 H

183.31±7 H

EIA (nominal)

GMI52.849.249.2

49.2CoSMIR49.349.3

49.349.3Footprint (km)GMI4.4x7.2

4.1x6.33.8x5.83.8x5.8

CoSMIR

1.3x1.9

1.3x1.9

1.3x1.9

1.3x1.9

11/25 clear air flightSlide12

GPM Overpass: Comparisons with GMI

Kroodsma OLYMPEX Workshop12

Channel89V

89H166V

166H

183.31±3

183.31±7

GMI-

CoSMIR

mean TB (K)

2.2

-0.5

1.91.11.93.8Locations of GMI/CoSMIR match-upsGMI vs. CoSMIR TBs by channel and date.

CoSMIR TBs are averaged over a GMI footprint.

89V89H166H

166V183.31±3183.31±7Slide13

Data Description

HDF5 files with 3 groupsAircraft: altitude, heading, latitude, longitude, pitch, roll, speedInterpolated to CoSMIR pixelsCosmir: azimuth, elevation, incidence angle, latitude, longitude, TBTime: year, month, day of month, hour, minute, second, millisecondQuicklook plots also available

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olympex_cosmir_YYYYMMDD_conical_v1.hdf5

olympex_cosmir_YYYYMMDD_crosstrack_v1.hdf5