NISAR satellite

Context : NISAR, the first joint satellite of NASA and ISRO, will be launched from the Satish Dhawan Space Centre in Sriharikota on July 30.

NISAR or NASA – ISRO Synthetic Aperture Radar

• The first satellite to observe the earth with a dual frequencySAR (Synthetic Aperture Radar).
  • NASA – L Band
  • ISRO – S Band
• Launch vehicle – GSLV- F16
• Orbit – sun synchronous
• Observe earth with high spatial resolution based on Sweep SAR technology for the first time and can detect even small changes on earth’s surface.
• Operate in all weather, day and night.
• Provide data at 12 day intervals.
• Most expensive earth observation satellite in the world with a cost of $1.5 Billion.

Applications of NISAR –

• Observe retreat of  glaciers
• Observe movement of sea ice sheet
• Observe path of storm and storm characterization.
•  Vegetation dynamics and forest cover
• Movements during earthquakes and volcanoes
• Ground deformation
• Observe soil moisture levels 
• Mapping and monitoring of surface water resources.
• Sea classification
• Shoreline monitoring
• Disaster Response.

What is an SAR?

Unlike optical imagery or cameras, SAR systems send out microwave pulses and record the echoes that bounce back from the ground, ocean, ice or buildings which are intercepted to turn these signals into high resolution sharp images even when it is dark or cloudy.