HRIRN3IM is the Nimbus-3 High-Resolution Infrared Radiometer (HRIR) data product containing scanned negatives of photofacsimile 70mm film strips. The images contain orbital daytime (0.7 to 1.3 microns) and nighttime (3.4 to 4.2 microns) brightness temperature values showing cloud cover and the Earth's surface temperature. Each orbital swath picture is gridded with geographic coordinates and covers a distance approximately from the south pole to the north pole (day) and the north pole to the south pole (night). The images are saved as JPEG 2000 digital files. About 7 days of images are archived into a TAR file. The processing techniques used to produce the data set and a full description of the data are contained in section 3.4.1 of the "Nimbus III Users' Guide."

The HRIR instrument was designed to perform two major functions: first to map the Earth's cloud cover at night to complement the television coverage during the daytime portion of the orbit, and second to measure the temperature of cloud tops and terrain features. The HRIR instrument was launched on the Nimbus-3 satellite and was operational from April 22, 1969 through January 31, 1970. Mr. G. Thomas Cherrix from Goddard Space Flight Center was the Principal Investigator.

This product was previously available from the NSSDC with the identifier ESAD-00223 (old ID 69-037A-02B).