Glossary

I

IEOS International Earth Observing System

IITA Information Infrastructure Technology and Applications (component of HPCC)

INMARSAT International Mobile (formerly Maritime) Satellite Organization

Integrated modular avionics Aircraft-unique avionics cabinet that replaces multiple black boxes with shared common equipment and generic software

INTELSAT International Telecommunications Satellite (Organization)

interferometry The production and measurement of interference from two or more coherent wave trains emitted from the same source

Internet An international computer network that began about 1970 as the NSF Net; very slowly it became a collection of more than 40,000 independently managed computer networks worldwide that have adopted common protocols to permit exchange of electronic information

ionosphere That region of the Earth's atmosphere so named because of the presence of ionized atoms in layers that reflect radio waves and short-wave transmissions

IORD Integrated Operational Requirements Document

IPCC International Panel on Climate Change

IRS-1B Indian Remote Sensing-1B (satellite)

ISO International Organization for Standardization

ISS International Space Station

ISTP International Solar Terrestrial Physics Program

ITU International Telecommunications Union; an intergovernmental organization founded in 1865 that became a specialized agency of the United Nations in 1947

ITWS Integrated Terminal Weather System

IUS Inertial Upper Stage

IV&V Independent validation and verification