November 28, 2025

RADAR Antenna Deployment

After the successful launch of NASA ISRO Synthetic Aperture Radar (NISAR) satellite onboard GSLV – F16 on July 30, 2025, the 12m diameter Antenna reflector has been successfully deployed. The 12-meter diameter antenna reflector plays a key role for both ISRO’s S-Band and NASA’s L-Band Synthetic Aperture Radar (SAR) Payload. The antenna was launched in a stowed condition on a 9m long boom, which was tucked closed to the satellite. The antenna and the 9m boom was developed by NASA.

The unfolding of the joints of the boom commenced on August 09, 2025 and was carried out over a period of five (05) days (Wrist, Shoulder, Elbow and Root deployments). The reflector assembly mounted on the end of the boom was deployed successfully on August 15, 2025 and the performance of the antenna systems are satisfactory.

The entire operations were carried out from ISRO Telemetry Tracking and Command Network (ISTRAC), ISRO with the support of JPL/NASA.

12m dia antenna reflector deployment image

Completion of Commissioning Phase:

Since the first acquisition on 19th August, 2025, NISAR S-Band SAR is regularly imaging over Indian Landmass and Global Calibration-Validation sites in various payload operating configurations. Reference targets such as Corner reflectors were deployed around Ahmedabad, Gujarat and a few more locations in India for calibration of the images. Data acquired over Amazon rainforests were also used for calibration of spacecraft pointing and images. Based on this, payload data acquisition parameters were fine-tuned resulting in high quality images. Initial analysis by scientists and engineers revealed the potential of S-Band SAR data for various targeted science and application areas like agriculture, forestry, geo-sciences, hydrology, Polar/Himalayan ice/snow and oceanic studies. The first image of S-band SAR acquired on 19th Aug 2025 captures the fertile Godavari River Delta in Andhra Pradesh, India. Various vegetation classes like mangroves, agriculture, arecanut plantations, acquaculture fields, etc are clearly seen in the image. The image highlights NISAR’s S-Band SAR ability to map river deltas and agricultural landscapes with precision.

In the 100^th day of NISAR in-orbit, the S-SAR images are released to the public by Chairman, ISRO/ Secretary DOS. With this, the commencement of science phase has also been announced.