Page 163 - Intro to Space Sciences Spacecraft Applications

150 Introduction to Space Sciences and Spacecraft Applications
in-orbit returns by investigating several electromagnetic regions simultane-
ously. Figure 6-7 shows the frequency bands used by modem remote sens-
ing systems, with the regions of interest aligned with particular frequency
ranges. Note that radiation in the short wavelength portion of the lR band and
the long wavelength portion of the UV band is detectable by photographic
film. Therefore, these wavelengths are included with the visible wavelengths
and are designated as the photographic remote sensing band.
In conclusion, it should be noted that mission application objectives and
remote sensors drive the spacecraft and orbit design. The sensor systems
are designed first to give the desired performances as described above, and
the other spacecraft systems (such as attitude control, power, and commu-
nications, which will be discussed in a separate chapter) are created to sup
port these sensors in the collection and transmission of the observed data
to the ground for synthesis, geophysical analysis, and dissemination.

REMOTE SENSING BANDS
-I -
PHOTO THERMAL
IR
GRAPHIC
RADAR
I
SPECTRAL GAMMA X-RAY [ 'EF RADIO
BANDS MICROWAVE
E
I I I I I I I I l l
.003 .03 .3 3 30 .3 3 30 300 .3 3 30 3 30 300
om nm nm nm nm pm pm pm pm an cm an m m m
WAVELENGTH
Figure 6-7. Remote sensing bands. Modern remote sensing satellites may
contain multiple sensors designed to investigate several areas within remote
sensing bands simultaneously.

REFERENCES/ADDITIONAL READING

Cantafio, L., Space-Based Radar Handbook. Boston: Artech House, 1989.
Sabins, E, Remote Sensing Principles and Intelpretation. 2nd ed. New
York: W.H. Freeman and Company, 1985.
Schnapf, A., Monitoring Earth's Ocean, Land, and Atmosphere from
Space- Sensors, Systems and Applications. Washington, D.C. : Ameri-
can Institute of Aeronautics and Astronautics, 1985.