“NovaSAR is a S-Band Synthetic Aperture Radar satellite intended for forest mapping, land use and ice cover monitoring, flood & disaster monitoring. S1-4 is a high resolution Optical Earth Observation Satellite, used for surveying resources, environment monitoring, urban management and for the disaster monitoring. Both satellites are planned to be launched into a 583 km Sun Synchronous Orbit,” Isro said.
According to SSTL, NovaSAR is a technology demonstration mission designed to test the capabilities of a new low cost S-Band SAR platform.
“The satellite was designed and manufactured by SSTL, with an S-Band SAR payload developed by Airbus Defence and Space in Portsmouth, UK and an Automatic Identification Receiver supplied by Honeywell Aerospace,” SSTL said in a statement.
Preparations before Sunday’s launch
SSTL adds that the SAR payload has a dedicated maritime mode designed with a very wide swath area (400-km) to enable the monitoring of the marine environment, and will provide direct radar ship detection information simultaneously with AIS ship tracking data to assist with the identification and tracking of sea-going vessels.
“In addition to operating in maritime mode, NovaSAR-1 has been optimised with three additional imaging modes, including a six metre resolution imaging mode, for a range of other applications, such as flood monitoring and agricultural and forestry applications,” SSTL said.
The S1-4 satellite, the firm said, is a sub one metre earth observation satellite identical in design to its DMC3/TripleSat Constellation satellites launched in 2015.
“SSTL, under a £110m contract, designed and manufactured three SSTL-300S1 satellite platforms, a new smallsat design which provides unparalleled 1-metre high resolution imagery with high speed downlink and 45 degree off-pointing. The three satellites formed a new constellation, TripleSat, with daily revisit times which is crucial for change detection, disaster monitoring and response planning, and essential for acquiring cloud-free imagery,” the firm said.
Also, in February this year, SSTL signed a contract with Twenty First Century Aerospace Technology to provide data from S1-4.
Why Night Launch?
On why the launch is scheduled at night— a rarity for PSLV launches as most of them happen early in the day— Isro scientists said it was keeping in mind the desired imaging requirements and illumination conditions.
“If it is a remote sensing satellite, it needs to have a certain illumination condition when it crosses the equator. So the main reason is the imaging requirements and the illumination conditions,” the scientist said.
A senior scientist from the Vikram Sarabhai Space Centre said that the UK partner had specifically sought this launch window as it helps achieve the required illumination.