Atul Kumar VarmaAtmospheric and Oceanic Sciences Group

Earth, Oceans, Atmosphere and Planetary Sciences Area

Space Applications Centre, ISRO, Ahmedabad 380015

(email: avarma@sac.isro.gov.in; Ph.: +91-79-26916045)

Evolution of Meteorological and Oceanographic Observations from

Indian Satellite Missions

Nowcasting and

aviation

applications (for

next few hours)

Numerical

Weather

Prediction (up to

10 days)

Seasonal Forecasts

(up to one season)

Extreme Events

Observational

needs for various

other applications

including climate

research

Sr Parameter Applications

1 Clear sky radiances NWP

2Atmospheric temperature and humidity profiles

NWP, Nowcasting, Cyclone, Thunderstorm

3 Atmospheric stability

Nowcasting, Aviation,

Thunderstorm, cyclone,

Monsoon

4

Cloud Properties

* Cloud Phase (CP),

* Effective Cloud Amount

(ECA),

* Cloud Top Pressure

(CTP)/

* Cloud Top Temperature

(CTT)* Cloud Effective Droplet Size, * Cloud Optical Depth

Nowcasting, Cyclone, NWP

5Atmospheric motion vectors / surface winds

NWP, Cyclone, Air-

Pollution, Thunderstorm, Monsoon

Sr Parameter Applications

6 3-D wind profiles

NWP, Cyclone, Air-

Pollution,

Thunderstorm, Monsoon

7Sea Surface Temperature (SST) Cyclone, NWP

8Land Surface Temperature (LST) NWP, Heat/Cold Wave

9 PrecipitationNowcasting, Cyclone,

NWP, Monsoon,Disaster Management

10 Soil Moisture NWP, Monsoon

11 FogAviation, Nowcasting,Disaster Management

12Aerosol Optical Depth (AOD)

NWP, Air-pollution, Climate, Monsoon

13 LightningNowcasting, Cyclone, Thunderstorm, Climate

14 Surface PressureNWP, Cyclone, Monsoon

Need for Satellite Measurements

Accuracy, timeliness, resolution - Spatial and Temporal Requirements

INSAT-2E

VHRR, CCD

Indian Meteorological Geostationary Satellites

1999

INSAT-1D

VHRRINSAT-2A/2B

VHRR

1992/93

1990

KALPANA-1

VHRR

2002

2013

INSAT-3D

Imager/ Sounder

INSAT-3A

VHRR, CCD

2003

2016

INSAT-3DR

Imager/ Sounder

2019

GISAT

MX-LWIR/MX-VNIR/

Hys-VNIR/Hys-SWIR2019

INSAT-3DS

Imager/ Sounder

2022+

INSAT-4 series

Being defined

INSAT-1A/1B/1C

VHRRApr 1982-Sep 1983

Aug 1983- 1999

July 1988-Nov 1999

Bhaskara-1

SAMIR, 2 TV cameras

at 600 & 800 nm

1979Bhaskara-2

SAMIR, 2 TV cameras

at 600 & 800 nm

1981

Oceansat-1

OCM & MSMR

1999

Oceansat-2

OCM, SCAT and ROSA

2009

Megha-Tropiques

MADRAS, SAPHIR, ScaRab

and ROSA

2011

SARAL

Ka-band Altimeter, radiometer

2013SCATSAT-1

Sactterometer

2016Oceansat-3

Sactterometer,

OCM and SSTM

2019

Indian Meteorological Low Earth

Orbiting Satellites

• Spectral Bands (µm)

Short Wave Infra Red : Six bands

Mid Wave Infra Red : Five Bands

Long Wave Infra Red : Seven Bands

Visible : One Band

• Resolution : 10 km

INSAT-3D/3DR

• Spectral Bands (µm) Resolution

Visible : 0.55 - 0.75 1 km

Short Wave Infra Red : 1.55 - 1.70 1 km

Mid Wave Infra Red : 3.70 - 3.95 4 km

Water Vapour : 6.50 - 7.10 8 km

Thermal Infra Red – 1 : 10.30 - 11.30 4 km

Thermal Infra Red – 2 : 11.30 - 12.50 4 km

6 Channel IMAGER 19 Channel SOUNDER

Improved Understanding of Mesoscale Systems

Sounder Products

T/Q – profile, Integrated Ozone

Derived products: Geopotential Height

Layer precipitable water, TPW, Lifted Index, Wind Index, Dry microburst Index

Imager Products

Precipitation, AMV (CMV, WVW), OLR, UTH, Fire & Smoke, Fog, SST

INSAT-3D: 82o E

INSAT-3DR: 74o E

a) Cloud mask

b) Rainfall

c) Sea Surface Temperature

d) Outgoing Longwave Radiation (OLR)

e) Atmospheric winds

f) Fog

g) TPW

h) CSBT

i) Upper Troposphric Humidity (UTH)

j) Temperature profile

k) Cloud products

l) Humidity profile

m) Ozone profile and total

n) Value added products

(thermodynamics indices)

INSAT-3D/3DR derived Meteorological ParametersSnow cover

Snow depth

Fire

Smoke

Aerosol

Potential evapotranspiration

Land surface insolation

Land surface temperature

Vertical Pressure Levels (40) in hPa :

1000, 950, 920, 850, 750, 700, 670, 620, 570, 500, 475, 430, 400, 350, 300, 250, 200,

150, 135, 115, 100, 85,70,60, 50, 30, 25, 20, 15, 10, 7, 5, 4, 3, 2, 1.5, 1, 0.5, 0.2, 0.1

INSAT – 3D/3DR/3DS & GISAT

Large scale Fog over IGP

Cyclone Cebile in Southern Indian Ocean

cyclone Phailin

• INSAT 3D/3DR – New Products

Algorithms for Clear Sky Brightness Temperatures (CSBT), Cloud Top Pressure (CTP), Cloud

Top Height (CTH), and TPW are developed.

●GSICS Calibration – operational for INSAT-3D/3DR

Figure: INSAT-3D Imager Channel Bias before and after GSICS correction coefficients

Global Space-based Inter-Calibration System:

ISRO as a member agency providing correction coefficients for INSAT-3D/3DR for

generation of climate data records to International community through MOSDAC.

LEO Missions Megha-Tropiques

SCATSAT-1

SARAL-AltiKa

Megha-TropiquesLow inclination (20º)

observations of tropics for

•Water vapour

•Clouds

•Cloud condensed water

•Precipitation

•Evaporation

• Water vapour profile

• Six atmospheric layers upto

12 km height

• Resolution: 10 km

• Swath: 2200 km

• Outgoing fluxes at TOA

• Resolution: 40 km

• Swath: 2200 km

• Swath: 1700 km

• Spatial Res.:

• Precipitation and cloud properties

• 89 &157 GHz : ice particles in cloud

tops

• 18 & 37 GHz: cloud liquid water and

precipitation

• 23 GHz : Integrated water vapour

SAPHIR

SCARAB

MADRAS

Launch Date: 12-Oct-2011

Fr Pol Pixel NE∆T

18.7 V & H ~ 40 km ~0.5 K

23.8 V ~ 40 km ~0.5 K

36.5 V & H ~ 40 km ~0.5 K

89 V & H ~ 10 km ~0.7 K

157 V & H ~ 6 km ~1.5 K

Fr Pol NE∆T

183±0.20 H 2.35 K

183±1.10 H 1.45 K

183±2.80 H 1.36K

183±4.20 H 1.38 K

183±6.80 H 1.03 K

183±11.0 H 1.10 K

Spectral Band (µm)

0.55-0.65 (visible)

0.2-4 (solar)

0.2-100 (total)

10.5-12.5 (TIR)

• Gohil, B S, R M Gairola, A K, A K Varma, C Mahesh, R K Gangwar and P K Pal, Algorithms for retrieval of Geophysical Parameters from MADRAS

and SAPHIR sensors of Megha-TropiquMathures Satellite – Indian Scenario, Quarterly Journal of Royal Meteorological Society, 139: 954–963,

2013.

• Varma, A. K., R.M. Gairola, B. S. Gohil, 2007, Retrieval of Geophysical Parameters over Oceans from MADRAS in Algorithm Theoretical Basis

Document: Retrieval of Geophysical parameters from Megha-Tropiques, report# ISRO/SAC/MT-UP/Retrieval-01/Nov-2007, pp 27-36..

TMI (Wentz Products)

SSM/I (Wentz Products)

MADRAS (SAC Products)CLW OWS TPW

MT-MADRAS

Rain associated with a depression on 9 November 2011

over Oman Sea from (a) MADRAS at ~1410 UTC (b)

TRMM-3B42 3-hourly averaged from 1200 UTC -1500

UTC (c) TRMM-TMI (2A12) at ~ 1510 UTC (d) TRMM-PR

(2A25) at ~1510 UTC and (e) SSMIS (Wentz) at ~1430

UTC.

Global monthly averaged rain rates for

November 2011 from (a) MADRAS and (b) TRMM

3B42 (c) SSM/I (Wentz).

Varma, A. K., D. N. Piyush, B.S. Gohil and P. K. Pal, A radiative transfer calibrated rain retrieval algorithm for MADRAS, Advances in

Space Research, 55, 1576-1589, 2015.

Correlation MADRAS 3B42 F15 F16

MADRAS 1 0.67 0.56 0.54

TRMM-3B42 0.67 1 0.58 0.64

SSMI F15 0.56 0.58 1 0.39

SSMI F16 0.54 0.64 0.39 1

Comparison of daily averaged rain

Rain from MADRAS

Challenges:

• Varying incidence angle across the scan –

(00 to 500).

• Varying pixel size across scan – 10 km

(nadir) – 40 km (pixel# 1 & 182).

Weighting Functions

• Layer averaged relative humidity was operationally

retrieved and provided from MT-SAPHIR.

Megha-Tropiques SAPHIR

SAPHIR: Rain identification and Measurement

Rain identification is probabilistic and specific to Scan location and for surface type

Over both land and oceans Rainy points that are

classified as non-rainy and otherwise would

contribute only to the very low rain

11 May 2013

Rain Measurement is based on difference of and

specific to Scan location and for surface type. It is

based on RT supported study and is based on

difference of Tbs measured at S1 and S6 channels

This provides R= 0.70rms , RMSE = 0.81 mm/h, Bias= 0.04 mm/h Varma, A. K., et al., Rain Detection and

Measurement from Megha-Tropiques Microwave

Sounder, JGR, 121, 2016,

doi:10.1002/2016JD024907.

Instantaneous @ ~2050 hr

3hourlyaveraged

hourlyaveraged

hourlyMW

cyclone Phailin on 11 Oct, 2013

LW Flux SW Flux

2014 2015 2014 2015

Year RMSD

(Wm-2)

Bias

(Wm-2)

2012 5.25 -2.48

2013 5.36 -2.53

2014 5.60 -2.64

2015 5.53 -2.63

Year RMSD

(Wm-2)

Bias

(Wm-2)

2012 24.48 5.87

2013 25.17 6.59

2014 27.93 5.87

2015 28.04 7.59

LW Flux

SW Flux

Validation @ 2 lat. × 2 lon. Boxes and Half hour interval; Under sampling is avoided; All scenes, all angles, Day & Night.

ScaRaB/MT Vs CERES/Aqua

MT-ScaRaB

Radio Occultation

GNSS-RO

• MT ROSA products such as T, P, RH

and refractivity profile are

operationalized at MOSDAC. MT-

ROSA products disseminated through

GTS to international agencies..

• Planetary RO mission:

• Work on retrieval of atmospheric profiles (T, P, H2SO4)

on Venusian atmosphere from Akatsuki mission

continuing.

Cyclone: OCKHI

High

Resolutio

n winds

SCATSAT-1:• IMS-2 Bus

• Ku-Band (13.515 GHz) Pencil beam Scatterometer

• Ground resolution: ~50 km x 50 km

• Swath: 1440 Km

• Polarization: HH and VV

• Wind Direction: O-360 deg with accuracy of 20 deg

• Wind Speed: 4 -24 m/s with accuracy of 10% or 2m/s

• Wind Vector is Retrieved with high accuracy

• High Resolution Wind (~6.25 km) is also being retrieved

• A new algorithm is developed for the retrieval of winds under rainy

conditions.

• Retrieved winds are used to generate ocean currents.

Range L2B 25 km (3-30 m/s)

(V.1.1.3A Oct, 2016-Jul, 2017)

WS BIAS

(m/s)

WS RMSE

(m/s)

WS URMSE

(m/s)

NP(#) (*106)

Rain free 0.02 1.10 1.10 124.21

Rain flagged – w/o Corr. 2.12 3.79 3.16 5.98

Rain flagged – With Corr. -0.07 1.93 1.93 5.96

Rain-Free Rainy

SCATSAT-1 Rain Corrected Measurements

SARAL – SAtellite for Argos and ALtiKa

AltiKa – Ka band Altimeter

ARGOS – Advanced Research and Global Observation

Satellite – data collection platform

Sunsynchronous orbit

Launch date: 25 Feb 2013

SARAL-AltiKa

FUTURE INDIANGEO SATELLITES: (GISAT)

Launch Schedule: ~2019, Geostationary orbit, 83EMX-VNIR: Multispectral - Visible Near Infrared, HySI-VNIR: Hyperspectral Imager - Visible Near Infrared,

HySI-SWIR: Hyperspectral Imager - Short Wave Infrared, MX-LWIR: Multispectral - Long Wave Infrared.

Band Ch SNR/

NEdT

IFOV

(m)

Range

(m)

Channels

(m)

MX-

VNIR

4 > 200 50 0.45 -

0.875

B1: 0.45-0.52B2: 0.52-0.59B3: 0.62-0.68B4: 0.77-0.86B5N: 0.71-0.74B6N: 0.845-0.875

HyS-

VNIR

60 > 400 500 0.375

- 1.0

< 10 nm

HyS-

SWIR

150 > 400 500 0.9 -

2.5

< 10 nm

MX-

LWIR

6 NEdT

<

0.15K

1500 7.0 –

13.5

CH1: 7.1-7.6CH2: 8.3-8.7CH3: 9.4-9.8CH4: 10.3-11.3CH5:11.5-12.5CH6: 13.0-13.5

GISAT Scan scenario Scan area for two scan scenario (5 & 10 )

Every 10

minute

interval

30-minutes triplet

every 6 hour for winds

• Tropical Cyclone

• Nowcasting

• Cloud properties

• SST/LST

• Rainfall

• Radiance Assim

• Winds

• Ozone wind

• Total Ozone

• SO2 Monitoring

• Atmospheric turbulence

• Fog application

• Climate application

Proposed PMR: Required Configurations

Freq.

(GHz)

Pol. NEDT Beam

Width

(in °)

Utilization Spatial

Res.

(Km)

Band

width

(MHz)

Justification

6.6 V+H 0.5K 2° SST and WS 38 * 62 350 SST and ocean wind speed variability is generally

muted below the 50-60 km range..10.65 V+H 0.5 K 1.6° SST and

wind speed31 * 50 200

18.7 V+H 0.5K 1° Oceanic RR 19 * 31 200 Require ~30 km or better foot print size to

characterize variability in ocean wind and

humidity parameters and get realistic ocean rain

distributions.

23.8 V 0.5K 0.8° IWV, WV

correction in

RR retrievals

15 * 25 400

36.5 V+H 0.5K 0.8° CLW, Ocean

RR, WS15 * 25 500

89 V+H 0.5K 0.3° RR over land

/oceans, WS5 * 9 2500 Require 10 km or better footprint size to

adequately characterize isolated convective rain.

157 V+H 1.5K 0.3° Ice at cloud

tops, cloud

microphysics

5 * 9 1200

183 V 1.5K 0.19o Light rain,

snowfall,

UTH

3.3*5 1000 A footprint of ~5 km allow the detection of small-

scale light rain or snowfall that is invisible at the

lower frequency channels with larger footprint

Channel observations to be resampled at 10 km spacing

along-scan with coincident pixel centres for all low and

mid-frequency channels (similar to MADRAS).

Swath=~1400km; Scan Rate=18

Altitude=725km

Sl.

No.

Channel

Name

Centre

Freq. (GHz)

Channel

Bandwidth

(MHz)

Polarization Weighting function peak

altitude at nadir/scan-edge

NEΔT(K)

(NF=5dB)

1 TS1 23.8 300 V, H Window+ water Vapor 0.27

2 TS2 31.5 300 V, H Window+ water Vapor 0.27

3 TS3 50.3 300 V, H Surface emissivity upto 1km 0.27

4 TS4 52.9 300 V, H 1km/ 2km 0.27

5 TS5 53.4 300 V, H 3km/ 4km 0.27

6 TS6 54.4 300 V, H 7km/9 km 0.27

7 TS7 54.95 300 V, H 10 km/11 km 0.27

8 TS8 55.5 300 V, H 13 km/14 km 0.27

9 TS9 56.65 300 V, H 16 km/18 km 0.27

10 TS10 57.55 100 V, H 26 km/28 km 0.47

11 TS11 58.8 300 V, H 18 km/19 km 0.27

12 TS12 59.38 240 V, H 21 km/22 km 0.3

13 TS13 58.39 60 V, H 29 km/30 km 0.6

14 TS14 56.97+0.02 20 V, H 32 km/33 km 1.06

15 TS15 56.97-0.02 20 V, H 30 km/32 km 1.06

16 TS16 59.59+0.01 10 V, H 36 km/38 km 1.5

17 TS17 59.59-0.01 10 V, H 39 km/40 km 1.5

Proposed TSU Channel specifications

Ch. No

Centre

Frequency (GHz)

Channel

Bandwidth (MHz)

Polarization

Weighting function

peak altitude at nadir/scan-edge

Sensitivity (K)

1 89 3000 V, H Surface 0.42

2 183.31±0.96 300 V, H 8 km/10 km 1.33

3 183.31±2.8 600 V, H 5 km / 7 km 0.94

4 183.31±5.8 700 V, H 3 km / 5 km 0.87

5 183.31±11.56

900 V, H 2 km / 4 km 0.77

6 183.31-15.7 1000 V, H 1 km / 3 km 0.73

Proposed HSU Channel specifications

More Future Sensors

• C & Ku band scatteromter

• Ka-band Radar Altimeter

• GNSS-R

WWW.APMC2016.ORG 25

METEOROLOGICAL & OCEANOGRAPHIC DATA & INFORMATION SERVICES FROM MOSDAC

Multi Mission Satellite Data Repository

Near Real-Time

KALPANA1 , INSAT3AOCEANSAT-2, MEGHA-TROPIQUESSARAL-ALTIKA, INSAT3D /3DRSCATSAT-1 and EUMETCAST

CAL-VAL – In situ DataDisdrometer, MicroRain Radar, GPS Sonde, Sun Photometer, Automatic Weather Station, Agromet Station, Automatic Rain Gauge, Hyper Spectral Radiometer, Fluorometer, Radio Sonde.

Weather Information Services

Science Products

Weather Forecast, Cyclogenesis, Cyclone track & Intensity, Sea State Forecast, All India Heavy Rain nowcast and forecast, Cloud burst over Uttarakhand and Himachal Pradesh, All India Heat/Cold wave forecast , Ocean State forecastingSea Ice Occurrence probability, Global Ocean surface Currents, Wave based REnewable energy, Inland water height, River Discharge

Tools & Utilities Mobile App, Visualisation and Analysis for multi-mission data

Research and TrainingSMART: Satellite Meteorology and Oceanography Research and Training

Planned MissionsINSAT-3DSGISATSCATSAT-2

26

TPWTotal Ozone

Hu

mid

ity

Pro

file

Daily long wave flux from SCARAB

Mean sea surface

Relative humidity SSH Anomaly

SST Sector Product WINDSNDVI

Visible band Asian sector

Full Disk Visible

MEG

HA

TR

OP

IQU

ES

SAR

AL

ALT

IKA

INSA

T –

3A

/ K

ALP

AN

A /

3D

/ 3

DR

INSA

T 3

D S

OU

ND

ER

Sample Satellite Data Products

Thanks