In 1972 a scheme was devised to reduce the influence of clouds. This technique employed a higher spatial resolution (30 km) and took spatially continuous sounding observations, now possible with cross-track scanning using the seven channel Infrared Temperature Profile Radiometer (ITPR) onboard Nimbus-5 (Smith et al. 1974a). With an adjacent field-of-view method, clear radiances could now be inferred by assuming that the variation in radiance between two adjacent fields-of-view was due to cloud amount only.

The ITPR instrument was highly successful in alleviating the influence of clouds on the synoptic scale. In fact, soundings to the earth's surface were now possible over 95 percent of the globe with an average spacing of 350 km.