Oceansat 2

Oceansat 2 [ISRO]

The ISRO (Indian Space Research Organization) spacecraft Oceansat-2 is an satellite provide service continuity for the operational users of OCM (Ocean Color Monitor) data provided by IRS P4 (Oceansat 1) as well as to enhance the application potential in other areas. The main objectives of Oceansat-2 are to study surface winds and ocean surface strata, observation of chlorophyll concentrations, monitoring of phytoplankton blooms, study of atmospheric aerosols and suspended sediments in the water.

Following instruments are on board:

• OCM (Ocean Color Monitor), an improved version of the one flown on Oceansat-1. OCM is a solid-state radiometer providing observations in eight spectral bands in the VNIR region. The instrument employs pushbroom scanning technology with linear CCD detector arrays (191 6K CCD) of 6000 elements (3730 active detectors in the center are used to cover the image field, the rest are used to correct for dark current). A swath width of 1420 km is provided. An along-track instrument tilt capability of ±20º is provided to avoid sun glint. OCM optics is based on one lens per band (wide angle telecentric lens design, refractive system). The ground resolution is 360 m in the along-track and 236 m in the cross-track direction.
• SCAT (Scanning Scatterometer), an active microwave device designed and developed at ISRO/SAC, Ahmedabad. The objective is to monitor ocean surface wind speed and directions. The instrument is a pencil beam wind scatterometer operating at Ku-band of 13.515 GHz. SCAT is being utilized for the estimation of the radar backscattered power and subsequent local and global wind vector (velocity magnitude and direction) retrieval over the ocean, from the normalized radar cross-section (?o), for cell resolution grids of 25 km × 25 km over a swath of 1400 km. The aim is to provide global ocean coverage and wind vector retrieval with a revisit time of 2 days.
• ROSA (Radio Occultation Sounder for Atmospheric Studies), a new GPS occultation receiver provided by ASI (Italian Space Agency). The objective is to characterize the lower atmosphere and the ionosphere, opening the possibilities for the development of several scientific activities exploiting these new radio occultation data sets.

A follow-on mission for the scatterometer is SCATSAT 1 as a gap-filler mission between OceanSat-2 and -3, which is to be launched in 2016. A successor mission is Oceansat 3 which is to be launched in 2018.