The Visible and Infrared Scanner (VIRS) sensor is one of the five instruments on the TRMM satellite. The VIRS instrument has a swath width of 720 km and a horizontal resolution of 2 km at nadir. VIRS is similar to the Advanced Very High Resolution Radiometer (AVHRR) now in operation on polar-orbital environmental satellites.

VIRS Channels

Channel         SpectralRegion         Wavelength (µm)        
1 Visible 0.63
2 Near Infrared 1.60
3 Near Infrared 3.75
4 Near Infrared 10.8
5 Infrared 12.0

TRMM VIIRS Level 1B01 Calibrated Radiance Product

The TRMM Visible and Infrared Scanner (VIRS) Level 1B Calibrated Radiance Product (1B01) contains calibrated radiances and auxiliary geolocation information from the five channels of the VIRS instrument, for each pixel of each scan. The data are stored in the Hierarchical Data Format (HDF), which includes both core and product specific metadata applicable to the VIRS measurements. A file contains a single orbit of data with a file size of about 95 MB. The EOSDIS "swath" structure is used to accommodate the actual geophysical data arrays.