. Agency Report of India Meteorological Department (GRWG+GRDG 2015) A.K.Sharma, A.K.Mitra .

Brief History of INSAT Satellites Satellite Meteorology in IMD really started in 1982 with the launch of INSAT-1A which was a multipurpose satellite meant for services to Meteorology, Doordarshan and Communication. Before that , Indian meteorologists were using analog imageries received from U.S. Polar orbiting satellites series of TIROS-N. Many satellites for meteorological purposes were launched after the launch of INSAT-1A as given below: INSAT-1A – 10 April 1982 Two Channel VHRR INSAT-1B – 30 August,1983 INSAT-1C – 21 July 1988 INSAT-1D – 12 June,1990 INSAT-2A – 10 July, 1992 INSAT-2B – 23 July,1993 INSAT-2E – 03 April 1999 Three Channel VHRR KALPANA-1 – 12 Sept.2002 INSAT-3A – 10 April 2003 INSAT-3D – 26 July,2013 --- 6 channel imager and 19 channel sounder

93.5o 74o 82o Current Indian Geostationary Meteorological Satellites INSAT-3A Kalpana-1 INSAT-3D:2013

INSAT-3A and Kalpana-1 Location : INSAT 3A : 93.5ºE Kalpana-1 : 74ºE (2003) (2002) Location : INSAT 3A : 93.5ºE Kalpana-1 : 74ºE Payloads :(i) VHRR and CCD camera in INSAT -3A (ii) VHRR in Kalpana-1 VHRR Bands (µm) Visible : 0.55 – 0.75 Water vapour : 5.70 – 7.10 Thermal Infra Red : 10.5 – 12.5 Resolution (km) : 2 X 2 for Visible 8 X 8 for WV & TIR CCD Camera Bands (µm) Visible : 0.62 – 0.68 Near Infra Red : 0.77 – 0.86 Short Wave Infra Red : 1.55 – 1.69 Resolution (km) : 1 X 1 for all bands

INSAT-3D - India’s Advanced Weather Satellite India's advanced weather satellite INSAT-3D was launched in the early hours of July 26, 2013 from Kourou, French Guyana, and has successfully been placed in Geosynchronous orbit. It carries four payloads Imager (Six Channels) Sounder (Nineteen Channels) Data Relay Transponder(DRT) Satellite Aided Search and Rescue (SAS & R)

Imager For meteorological observations, INSAT-3D carries a multi-spectral Imager (radiometer) capable of generating the images of the earth in six wavelength bands significant for meteorological observations, namely, visible, shortwave infrared, middle infrared, water vapor and two bands in thermal infrared regions. The Imager generates images of the earth disk from geostationary altitude of 36,000 km every 26 minutes and provides information on various parameters, namely, outgoing long-wave radiation, quantitative precipitation estimation, sea surface temperature, snow cover, cloud motion winds, etc. Imager payload is an improved version of VHRR flown on INSAT-3A and Kalpana-1 satellites with significant improvements in spatial resolution, number of spectral channels and functionality.

INSAT 3D satellite Imager Channels Spectral Band Wave-length(µm) Ground Resolution Visible 0.55-0.75 1 km SWIR 1.55-1.70 MIR 3.80-4.00 4km WV 6.50-7.10 8km TIR1 10.2-11.3 TIR2 11.5-12.5 7

Atmospheric Sounder INSAT-3D also carries a newly developed 19 channel sounder, which is the first such payload to be flown on an ISRO satellite mission. The Sounder has eighteen narrow spectral channels in shortwave infrared, middle infrared and long wave infrared regions and one channel in the visible region. It provides information on the vertical profiles of temperature, humidity and integrated ozone. These profiles are available for every 30X30 kms over a selected region over Indian landmass every one hour and for the entire Indian Ocean Region every six hours.

Detector Long wave Mid wave Short wave Visible INSAT-3D Sounder Channels Characteristics Detector Ch. No. l c (mm) nc (cm-1) NET @300K Principal absorbing gas Purpose Long wave 1 14.67 682 0.17 CO2 Stratosphere temperature 2 14.32 699 0.16 Tropopause temperature 3 14.04 712 0.15 Upper-level temperature 4 13.64 733 0.12 Mid-level temperature 5 13.32 751 Low-level temperature 6 12.62 793 0.07 water vapor Total precipitable water 7 11.99 834 0.05 Surface temp., moisture Mid wave 8 11.04 906 window Surface temperature 9 9.72 1029 0.10 ozone Total ozone 10 7.44 1344 Low-level moisture 11 7.03 1422 Mid-level moisture 12 6.53 1531 Upper-level moisture Short wave 13 4.58 2184 N2O 14 4.53 2209 15 4.46 2241 16 4.13 2420 Boundary-level temp. 17 3.98 2510 18 3.76 2658 Visible 19 0.695 14367 - visible Cloud

Activity :1 Calibration/Validation Site for INSAT-3D 1.To calibrate optical sensors on INSAT-3D First joint campaign by scientists of IMD, ISRO, NPL and IITM has been carried out at Jaisalmer, Rajasthan recently ( 15-22 Dec;2013). This will facilitate making climatic studies using INSAT-3D and follow on satellites data in future.( Report presented by AKM). 2. A second site selection is being done at Bhuj, Gujrat.

Runn of Kutch Gujrat

White Runn of Kutch, Gujrat

Activity 2:Calibration of old archived data India Meteorological Department is receiving and archiving satellite meteorological data from INSAT series since 1982. Data is already archived on DLTs and resolutions of these data are 2.75 km/2km in visible, 11km/8km in infrared channels for INSAT-1/INSAT-2 series respectively. The normalized calibration technique is attempted in order to re-calibrate the Kalpana-1 Infrared data and remove the effect of the temporal non-linearity of sensor response due to degradation of the sensor based on ISCCP (International satellite cloud climatology project) procedure over the Indian Ocean. Table- KALPANA-1 Satellite Specification Payload Channels Bandwidth Resolution VHRR (Very High Resolution Radiometer) Visible Infrared Water vapour 0.55µm-0.75µm 10.5µm-12.5µm 5.7µm-7.1µm 2km x 2km 8km x 8km 8km X 8km DRT ( Data Relay Transponder) ----- ------

DATA AND METHODOLOGY Data collection: Study Covers the months MAY, JUNE, JULY, OCTOBER, NOVEMBER and DECEMBER of 2009. Taking 8-10 passes of NOAA of each month. Four automated steps to satellite Inter-calibration :: Data collection: Study period: MAY, JUNE, JULY, OCTOBER, NOVEMBER, DECEMBER 2009. Study region: ± 10º NS latitude of the equator; 64º-84º longitude east Primary data for inter-calibration :: kalpana-1 Geostationary satellite VHRR Infrared brightness temperatures Polar Orbiting Satellite used :: NOAA-19 AVHRR channel-4 brightness temperatures, data accessed through INCOIS, Hyderabad and its collection based on currently operational satellite series status of imager AVHRR ISCCP survey on data availability

Table: Satellite Specifications for the study Satellite / Imager Channel Bandwidth Resolution Data Format Kalpana-1/ VHRR Infrared 10.5µm - 12.5µm 8km X 8km H5 NOAA / AVHRR 4 10.3µm - 11.3µm 1km X 1km Hdf4

Study area of interest : ….Contd The impact of spectral differences between the IR win channels is important to consider when comparing brightness temperatures to those from AVHRR. a) b) Fig a) Shows the spectral response function of NOAA-AVHRR channel-4 and b) Kalpana-1 Infrared respectively. Study area of interest : The strategy is to find the measurements by the polar orbiting satellite that are concurrent and collocated with those from a geostationary satellite. The near-simultaneous nadir observations with homogeneous scenes from NOAA and Kalpana-1 imagers are spatially collocated.

Collocation Criteria :: …Contd Domain of the earth for the study ::: ±10º NS latitude of the equator, 64º- 84º longitude east Time differences between observations should be less than 30min. Collocation Criteria :: Study Region selected for inter-calibration process . Constraint Criteria Simultaneity Observational Time difference < 30min View geometry Area of domain [10⁰S/10⁰N and 64⁰E/84⁰E] of the earth selected which matches with NOAA satellite. Collocation criteria Nearest neighbour distance technique is used to perform linear search iteratively to find closest point for Kalpana-1 points (latitude-longitude) in NOAA AVHRR data with maximum outer threshold to be 20 km. The least distance point would be selected for collocation.

Scatterplot of Kalpana-1infrared brightness temperatures versus NOAA AVHRR channel-4 brightness temperatures for whole defined region; MAY JUNE JULY OCTOBER NOVEMBER DECEMBER

Scatterplot Kalpana-1 infrared brightness temperatures versus NOAA AVHRR channel-4 brightness temperatures for CLOUDY REGION [ for those brightness temperatures of Kalpana-1 Infrared less than 273.15 K ] ; MAY JUNE JULY OCTOBER NOVEMBER DECEMBER

Scatterplot Kalpana-1infrared brightness temperatures versus NOAA AVHRR channel-4 brightness temperatures for CLEAR SKY [ for those brightness temperatures of Kalpana-1 Infrared greater than 273.15 K ] ; MAY JUNE JULY OCTOBER NOVEMBER DECEMBER

  SCM-06 (IOGEO) project 1.Inter-calibration of passive INSAT imager observations from time-series of geostationary satellites (IOGEO) 2.IMD has become part of the SCM-06 IOGEO project team.

Activity 3: INSAT-3D Inter-calibration with NOAA19 and Metop-A Area : 60E to 90E -10S to 50N Time Difference: 10 minute Crieria: Co-located Observations/Passes: 0600 to 0900 UTC

FEB 2015 Comparison of INSAT 3D TIR1 Channel (10.3 um - 11.3um) with NOAA / METOP TIR1 Channel

FEB 2015 Comparison of INSAT 3D TIR1 Channel (3.8 um - 4.0um) with NOAA / METOP MIR Channel

BIAS

RESULTS From the above drawn analysis we can conclude that INSAT 3D channels ( MIR and TIR1 Channel) predicts the brightness temperature colder as compared to NOAA/ METOP channels. In addition, INSAT 3D TIR1 channel has an average of 2.5K BIAS in the month of FEB 2015 as compared to NOAA / METOP in the passes from 0600UTC to 0900UTC. The brightness temperatures of MIR channels of INSAT 3D and NOAA /METOP satellites for the passes from 0600UTC to 0900UTC in the month of FEB2015 gives an average BIAS of 1.9K. Furthermore warmer places (having temperature 295K and above) show more deviations in temperatures as compared to colder places.

THANK YOU FOR YOUR KIND ATTENTION A.K.SHARMA