Remote Sensing - Measurements 4.1.1. To measure water vapor, radiometers operate in the infrared or microwave bands. They measure brightness temperatures. These brightness temperatures are converted to path delays. Water refractive properties and emissive effects are known, therefore the integral equation of radiative transfer is used to extract the water content of the atmosphere.
Microwave radiometers provide good coverage of water vapor over the oceans.
POES is an entire series of satellites. The first was launched in 1978, and there are several in operation today. The POES orbit about every 102 minutes at an altitude of 833 km. Sounding is the identification of atmospheric constituents based on detecting the presence of spectral lines associated with a specific molecule. Determining abundance requires additional measurements.