ITPRN5L1 is the Nimbus-5 Infrared Temperature Profile Radiometer (ITPR) Level-1 Calibrated Radiances data product which contains radiances at 7 infrared spectral regions (2683.0, 899.0, 747.0, 713.8, 689.5, 668.3, and 507.4 cm-1) in a single binary data file. Four are centered near the 15 micron CO2 band, one interval in the water vapor rotational band near 20 microns and two spectral intervals in the atmospheric window regions near 3.7 and 11 microns. The instrument scan sequence consists of three separate grid matrices, to the right, center and left of nadir. Each matrix consists of 10 scan lines with 14 scenes per scan. Each scan footprint is 32 km wide. Due to problems with the instrument, data are limited to three time periods from 14 February 1975 to 1 March 1975 covering East Asia, from 10 May 1976 to 4 June 1976 covering the United States and the Gulf, and from 1 September 1976 to 30 September 1976 covering southern Australia and New Zealand. The principal investigator for the ITPR experiment was William L. Smith from NOAA.