Page 147 - Intro to Space Sciences Spacecraft Applications

Introduction to Space Sciences and Spacecraft Applications
134
The combined data from passive and active sensors, spanning the elec-
tromagnetic spectrum, allows users to study a host of important ecologi-
cal, economic, and environmental subjects including crop coverage,
health, and yield; land use and erosion; ocean and coastal conditions; and
the effects of man on his environment in the form of pollution or deple-
tion of the amount of ozone in the upper atmosphere.

Applications and Sponsorship

The genesis of remote sensing missions is usually associated with some
applications goal that is sponsored by a civil governmental, military, or
commercial organization. First efforts are usually exploratory research or
proof-of-concept systems used to find the right sensor combinations and
orbits for observation. If these research efforts prove successful, and a
sustaining need can be established for the information that can be provid-
ed by the space-based remote sensing system, then a decision may be
made to continue with a series of operational satellites that provide a con-
tinuum of information. For example, the aforementioned Tiros experi-
ments led to the NOAA (National Oceanic and Atmospheric Administra-
tion), GOES (Geostationary Operational Environmental Satellite), and
military DMSP (Defense Meteorological Satellite Program) satellite
series. This evolutionary process has led to a number of established oper-
ational missions that continuously collect information about the earth, bal-
anced by one-of-a-kind exploratory or scientific missions that constantly
probe our earth, solar system, and universe in an effort to better explain
the physical processes that govern our existence.
Any attempt to rigidly classify missions erodes under the progress of
technology, budgets, and sovereign or national interests. At present, most
developed nations have the capability to create, operate, and sustain a
wide-ranging space remote sensing program that can be segmented into
intelligence, military, civil governmental, and commercial operational
programs as well as a varied set of progressive scientific exploration pro-
grams. With the exception of the protective and narrowly sovereign mili-
tary and intelligence programs, many of the remaining mission categories
are becoming shared efforts, with many nations combining their resources
and technologies to produce cooperative benefits. The ever-expanding
base of sensor technologies, missions, and international sponsors has pro-
duced a robust interest in, and reliance on, space remote sensing-all
stemming from the fact that the vantage of space allows man to look at