Sensors are instruments that collect data about Earth processes or atmospheric components. Along with being carried aboard satellites or aircraft, sensors also can be installed on the ground (in situ). There are two types of sensors: active and passive. Active sensors provide their own source of energy to illuminate the objects they observe; passive sensors detect energy emitted or reflected from the environment. The following list describes sensors aboard NASA and joint NASA missions.

DORIS measures radio signals from 55 global ground stations that compose the International DORIS Service (IDS).
DPR, aboard the Global Precipitation Measurement (GPM) Core Observatory measures mid-latitude rainfall and snowfall over land and ocean.
EPIC provides color images of the entire sunlit face of Earth from 1 million miles away at least once every two hours.
PHyTIR aboard NASA’s Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission monitors plant temperature to assess plant stress.
ETM+ is a fixed “whisk-broom”, eight-band, multispectral scanning radiometer that provides high-resolution images of Earth’s surface.
GLAS provided elevation data for determining ice sheet mass balance, global topography and vegetation data, and cloud property information.
GLM detects and maps total lightning and reveals the extent of lightning flashes and the distance these flashes travel.
GEDI is a full-waveform lidar that makes detailed measurements of the 3D structure of Earth's surface.
GMI is a radiometer that is sensitive to microwave energy emitted from or affected by precipitation types including rain, snow, ice, water vapor, and mixed precipitation.
GRACE and GRACE-FO missions consist of two identical satellites that act in unison as the primary instrument to provide data about changes in Earth's gravity field.
An ocean color imager of SeaWiFS caliber providing high spatial resolution imagery and observations of fjords, estuaries, coral reefs.
The airborne HAMSR technology demonstration instrument analyzes the heat radiation (brightness temperature) emitted by atmospheric oxygen and water molecules to determine their density and temperature.
HiCARS is an airborne, ice-penetrating radar used to build profiles of ice sheets.
HIRDLS was a scanning infrared limb-scanner radiometer that acquired a wide range of measurements from the upper troposphere, stratosphere, and mesosphere.
HRGS measures properties of light within the electromagnetic spectrum to study atmospheric carbon dioxide from space.
HSB was a four-channel microwave sounder designed to obtain atmospheric humidity profiles under cloudy conditions and to detect heavy precipitation under clouds.
IIR is a nadir-viewing, non-scanning radiometer that acquires data in wavelength channels that optimize retrievals of cirrus cloud emissivity and particle size.
JMR collects radiation reflected by the ocean to measure atmospheric water vapor content and study other atmospheric phenomena, particularly rain.
KaRIn is an altimeter used to measure surface heights
KSSTS is a radiometer that measures the brightness temperature of the surface beneath an aircraft.
KBRA is an airborne instrument designed to collect high precision surface elevation measurements over polar ice sheets.
LBR detects emitted radiation in the frequency range of 1-2 GHz in the radio spectrum and have a wavelength range of 30-15 cm.
LAGEOS was the first spacecraft dedicated exclusively to high-precision laser ranging.
LIS is a space-based instrument used to detect the distribution and variability of total lightning (cloud-to-cloud, intra-cloud, and cloud-to-ground lightning). It measures the amount, rate, and radiant energy of lightning.