The Progress of Landsat Sensor Technology
Landsat sensor technology has come a long way since the days of the Return Beam Vidicon cameras on the first three Landsat satellites. Known as the RBV, it was originally intended to be the satellites' primary sensor. But the Multispectral Scanner, or MSS, became the more stable and superior instrument.
Compare these images of glaciers in Alaska's Chitina River Valley from 1980. There is more background noise in an RBV image than there is in an MSS image. The RBV on Landsat 3 had a slightly higher spatial resolution, but the low signal-to-noise ratio makes it harder to pull out surface detail.
The 2018 image from Landsat 8's Operational Land Imager has even better signal-to-noise ratio and higher resolution than both early sensors. The image reveals more detail about the roughness and flow of the ice. Landsat 8's shortwave infrared bands provide a better distinction between ice and rock or soil.
Although Landsat sensor technology has improved, RBV data still play an important role in this long-term record of changes on the earth.