ISRO RADAR DEVELOPMENT UNIT, BANGALORE

ISRO RADAR DEVELOPMENT UNIT, BANGALORE.

PRESENTATION TO CHAIRMAN - ISRO & MEMBERS - ISRO COUNCIL NRSA LECTUREGPM – GV MEETING # 2

ISRAD

GROUND VALIDATION INDIAN SCENARIO G.VISWANATHAN - ISRO

presented by PROF. V. CHANDRA


PRESENTATION TO CHAIRMAN - ISRO & MEMBERS - ISRO COUNCIL NRSA LECTUREGPM – GV MEETING

ISRAD

PRESENTATION SEQUENCE:

GenesisOngoing EffortsInstrumentationSample Data from OpportunitiesPlans for futureRelevance to GPM



ISRAD

Genesis

•GV efforts @ ISRO started with TRMM through then NASDA, with GV as PI from ISRO & T.Kozu from CRL• SHAR for NE Monsoon & Thumba for both SW & NE Monsoon coverage•Converted C band tracking Radars with Weather channel•MST radar (VHF Profiler along with Disdrometer (VV) & Optical Rain gauge @ Gadanki)•Resulted in major collaboration with CRL Japan



ISRAD

Ongoing efforts:GV work continued more as an inter comparison of data from Doppler Weather Radar (Megha -2700) with TRMM as per opportunities Helped as an indirect validation of DWR Products (Z) once TRMM is well establishedCollaborative work in progress between ISRAD & Academic Institutions in India Gearing up for GV for Megha - Tropiques & GPM



ISRAD

INSTRUMENTATION SYSTEMS Radar Systems :

S Band Doppler Weather Radar – Megha 2700Converted C Band Tracking Radar with weather channel Other Instruments :DisdrometerFast Response RainGauges (Siphon type )Surface Observatories with TB Rain Gauges



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MEGHA – 2700 Doppler Weather Radar



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Reflectivity Velocity Sp Width

1. Range (Km) 500 250 2502. Resolution ( m) 300 300 3002. Accuracy @23 dBZ 2 dB 1 m/s 1 m/s

@ 2 rpm3.Unambiguous maximum velocity +/- 30 m/s for 125 Km Ambiguity Resolution techniques to extend velocity to +/- 60 m/s for 125 Km or +/- 30 m/s for 250 Km.

Design goal +/- 60m/s for 250 km

DWR System SpecificationsDWR System Specifications



ISRAD

Klystron based coherent transmitterLow phase noise signal generationProgrammable waveformsHigh dynamic range Log / Lin Receiver14 bitADCs PC-PCI bus DSP boardsPC based radar controllerData Products on Graphic WorkstationsGIS based Product overlayCalibration using built in source, & SunLow sidelobe level Pencil beam antennaProgrammable Antenna scan functionsSandwich Radome to withstand gale speeds of 250 Km/hrPolarimetry to be included shortly

DWR System Features



ISRAD

MEGHA -2700 CONTROL CONSOLE & WORK STATIONS



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THUNDERSTORM -Z



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THUNDERSTORM -V



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CAPPI@1Km Rain Rate

PRECIP DATA PRODUCTS

Rainfall recorded w ith IISc rain gauge at SHAR on 06-12-2002

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

7:00 7:30 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00 12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30

time

rain

fall

in m

m

GAUGE DATA



ISRAD

OBSERVATION OF CYCLONES OVER BAY OF BENGAL

• CYCLONES ARE CONTINUOUSLY MONITORED USING DWR OPERATED WITH DIFFERENT SCAN STRATEGIES UNDER TIME TAGGED SCHEDULER MODE•RADAR WAVE FORM FOR EACH STRATEGY IS SO CHOSEN TO PROVIDE LONG RANGE OBSERVATIONS •DUAL PRF TECHNIQUE USED TO MINIMISE RANGE - DOPPLER AMBIGUITIES AT LONG RANGES



ISRAD

Z V

BAY OF BENGAL CYCLONE OF DECEMBER 15, 2003

V

DWR OBSERVATIONS



ISRAD

GV FOR SPACE BORNE PRECIPITATION ESTIMATION INTERCOMPARISON WITH TRMM

DWR WAS OPERATED FOR INTERCOMPARISON WITH TRMMON A CAMPAIGN MODE OBSERVATIONS

SIMULATANEOUS MEASUREMENTS WITH FAST RESPONSERAINGAUGE & DISDROMETER CARRIED OUT

SAMPLE DATA PROVIDES A TYPICAL INTERCOMPARISON



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PPI Plot (06 November 2003)DWR (SHAR) (307 Km)

0.5° elevation

Figure 1: PPI Plot of DWR Reflectivity over SHAR on 6th November 2003 (07:03:38 UTC)



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0

5

10

15

20

25

30

35

40

45

50

14 N

Longitude

La

titu

de

SRI LANKA

12 N

78 E 80

E 82

E 84

E

8 N

88 E

90 E 92

E 94

E 96

E 98

E 100

E 10

N

SHAR

dBZ

PR Scan (06 November 2003)Orbit No. 34082



ISRAD

80.6 80.8 81 81.2 81.4 81.6 81.8 82 82.2 82.4 82.611.2

11.4

11.6

11.8

12

12.2

12.4

12.6

Longitude

Latit

ude

0

5

10

15

20

25

30

35

40

45

50

Longitude

Lat

itu

de

80.6 80.8 81 81.2 81.4 81.6 81.8 82 82.2 82.4 82.611.2

11.4

11.6

11.8

12

12.2

12.4

12.6

0

5

10

15

20

25

30

35

40

45

50

Longitude

FOV = 1 to 19

(a) (b)

PR dBZ at 5.5 Km heightDWR CAPPI

Magnified View of near simultaneous reflectivity observations of (a) DWR and (b) PR (TRMM) on 06 November 2003

INTERCOMPARISON WITH TRMM-PR(a)

(b)

(a) Vertical cross section of DWR (SHAR)

(b) PR for the 7th Nov 2003 event. DWR azimuth 136° corresponds to FOV 34 of PR orbit no.

34082.ISRO RADAR DEVELOPMENT UNIT, BANGALORE.


ISRAD

DIFFERENCES IN GROUND RANGE ARE DUE EARTH CURVATURE RECONNING



ISRAD

D DISDROMETER MEASUREMENTS @ SHAR

ANALYSIS COURTESY : Dr.Sanjay Sharma, Kohima Science College, Nagaland University.



ISRAD

PLANS FOR IMMEDIATE FUTURE:

POLARIMETRIC UPGRADE FOR DWR

MESO NETWORK OF AWS WITH RAINGAUGES

INTGRATED OBSERVATION & MODEL ASSIMILATIONFOR NOWCASTING WEATHER FOR LAUNCH SUPPORT

CO LOCATED WIND PROFILER FOR CONVECTION STUDY

Ka BAND PATH ATTENUATION MEASUREMENTS WITH BEACON

GV FOR MEGHATROPIQUES

POTENTIAL INTERNATIONAL COLLABORATION FOR GPM



ISRAD



ISRAD

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ISRO RADAR DEVELOPMENT UNIT, BANGALORE