The first year of the selective chopper radiometer on Nimbus 4

The selective chopper radiometer, an instrument for the remote measurement of atmospheric temperature from the surface to about 50 km altitude, was launched on the Nimbus‐4 satellite in April 1970. The performance of the instrument during its first year of operation is described. Good data have been received throughout this period. Various mean atmospheric cross‐sections, temperature profiles and thickness maps are presented as examples of the data which are available from the instrument.