Radiometer
An instrument that measures the intensity of electromagnetic energy — visible light, infrared, or microwaves — coming from a scene. It is essentially a very precise, calibrated light or heat meter flown in space.
Radiometer
An instrument that measures the intensity of electromagnetic energy — visible light, infrared, or microwaves — coming from a scene. It is essentially a very precise, calibrated light or heat meter flown in space.
Why it matters
Radiometers turn the energy reaching the satellite into numbers scientists can trust over decades, making them the workhorses behind temperature, moisture, and color measurements across the whole Earth system.
Where you’ll meet it
- SMAP carries a microwave radiometer to measure soil moisture.
- AMSR2 is a multi-channel microwave radiometer for ocean and cryosphere products.
- MODIS and VIIRS are imaging radiometers spanning visible to thermal-infrared wavelengths.
In plain terms
It’s like a light meter a photographer holds up to a scene — except this one is calibrated so precisely you can compare today’s reading to one taken twenty years ago.