Electromagnetic - Relating to the interplay between electric and magnetic fields.

Electromagnetic radiation - Energy transfer in the form of electromagnetic waves or particles that propagate through space at the speed of light.

Electromagnetic spectrum - The entire range of radiant energies or wave frequencies from the longest to the shortest wavelengths--the categorization of solar radiation. Satellite sensors collect this energy, but what the detectors capture is only a small portion of the entire electromagnetic spectrum. The spectrum is usually divided into seven sections: radio, microwave, infrared, visible, ultraviolet, x-ray, and gamma-ray radiation.

Enhanced Thematic Mapper Plus (ETM+) - The sensor aboard Landsat 7 that picks up solar radiation reflected by or emitted from the Earth.

Ephemeris - A table of satellite orbital locations for specific time intervals. The ephemeris data help to characterize the conditions under which remotely sensed data are collected and are commonly used to correct the sensor data before analysis.

Equator - An imaginary circle around a body that is everywhere equidistant from the poles, defining the boundary between the northern and southern hemispheres.

EROS Data Center (EDC) - Earth Resources Observation System (EROS) Data Center (EDC) is a national archive, production, distribution and research facility for remotely sensed data and other geographic information.

ETM+ Format 1 - The ETM+ Format 1 major frames contain all data (e.g., imaging and calibration) from and associated with Bands 1–6. The MSCD and PCD data are duplicated in both ETM+ formats.

ETM+ Format 2 - The ETM+ Format 2 major frames contain all data (e.g., imaging and calibration) from and associated with Bands 6–8. The MSCD and PCD data are duplicated in both ETM+ formats.