The document discusses various applications of the electromagnetic spectrum from visible light to radio frequencies. It describes instruments that observe different wavelengths, including the Hubble Space Telescope, weather satellites, infrared and ultraviolet telescopes, x-ray and gamma ray observatories, and radio antennas. Examples of images captured across the spectrum illustrate observations of astronomical phenomena, Earth's atmosphere and surface, and scientific discoveries enabled by each wavelength band.

1. 9 May 2006
Using the Electromagnetic
Spectrum
Mark Webster
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2. 9 May 2006
Outline
• The Electromagnetic Spectrum
• Optical Instrument Design
• Visible Light Applications
• Infrared Observations
• Ultraviolet
• X-ray
• Gamma Ray
• Radio Frequency Applications
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3. 9 May 2006
The Electromagnetic Spectrum and its use in
Space Instruments
• The Earth’s atmosphere absorbs a large part of the
electromagnetic spectrum
• Information about the universe (and the Earth) can be obtained
from wavelengths other than light
• The primary advantage of Earth viewing space instruments is
field of view, using a geosynchronous orbit to maintain a
constant viewpoint and 24/7 operation
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4. 9 May 2006
Optical Instruments
Engineering Disciplines:
Optical Engineer
Controls Engineer
Mechanical Engineer
Thermal Engineer
Structural Engineer
Electronic Engineer
Software Engineer
Calibration Engineer
Detector Engineer
Program Manager
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5. 9 May 2006
Hubble Space Telescope
• 2.4 meter diameter primary
mirror
• 0.01 arc sec resolution (a dime
from 500 miles away)
• Telescope has a flaw in its
prescription, was given “glasses,”
(corrective optics) in the first
servicing mission
• Four scientific instruments
– Wide Field Planetary Camera 2
– Near-Infrared Camera and Multi-
Object Spectrometer
– Space Telescope Imaging
Spectrograph
– Advanced Camera for Surveys
• Two new instruments to be added
on next servicing mission
– WFPC3
– Cosmic Origins Spectrograph
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6. 9 May 2006
Pictures from Hubble
Eagle Nebula-
Birthplace of Stars
Debris Disk around a
star, birthplace of
planets
Hubble Deep Field –
every point a galaxy
Hubble is the most
successful space
mission ever 6

7. 9 May 2006
Weather and Environment Instruments
Geosynchronous
weather satellites
are in orbits that
keep them in one
spot over the
Earth
Low Earth orbit
weather satellites
are closer in and
can take pictures
with higher
resolution
Katrina approaches New Orleans 7

8. 9 May 2006
Laser Communications and Science
Visible light lasers can
Visible light can be also be used to do
used for science. Calypso will
communications use laser light to
between satellites in measure the properties
space using lasers of aerosols (suspended
particles) in the Earth’s
atmosphere
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9. 9 May 2006
The Spitzer Space Telescope Looks at the
Universe in the Infrared
Black Widow nebula is only visible in the
infrared
A massive hot cloud of gas surrounding M82
can only be seen with infrared detectors 9

10. 9 May 2006
Infrared Earth Observation
• Infrared Earth Observation also provides additional information:
– The picture on the left is made from a long series of infrared observations
of Antarctica that show how much the temperature has changed
– The picture on the right shows that actual locations of the fires that are
producing the long plumes of smoke, this information comes from
infrared fire channels
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11. 9 May 2006
Ultraviolet
Flight-Tested Composite Electronics and CPU with
Structure and Kinematic UV/VIS Limb Radiometry Established Flight Heritage
Mounts from STIS, Demonstrated on (Mars Pathfinder, Surveyor)
NICMOS, UVCS, SWAS SOLSE/LORE
UV Nadir Radiometry
Extends TOMS, SBUV/2
Data Heritage
Radiation-Tolerant
Calibration Techniques Optical and Electronic
Proven on SSBUV, Components (HST
TOMS Programs, UVCS, RME)
Crosstrack
Conservative CCD
Approach Based on STIS,
SAGE III, and ACS Flight
Grating Spectrometers Proven on Nadir
SBUV/2 and TOMS A7785_T104
The Ozone Mapping and Profiling
Spectrometer will use ultraviolet
light to look at the Earth’s ozone
The Ozone hole over Antarctica as
it appears in ultraviolet light
The Aurora Borealis can be seen
using ultraviolet light even in the
day time 11

12. 9 May 2006
X-Ray
The Chandra X-ray observatory
The Crab Nebula pulsar as it appears to the
x-ray sensors on Chandra
The sun as it appears in X-ray wavelengths
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13. 9 May 2006
Gamma Ray Observations
• The Compton Gamma-Ray Observatory carried 4 instruments, all of which detected
gamma rays of various energy levels indirectly
• The image was created by measuring the intensity of gamma rays as the spacecraft was
pointed in all directions
• NASA de-orbited the observatory in 2000 after a gyro failed
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14. 9 May 2006
Radio Frequency Antennas and Applications
(Looking Up)
Radio Image of the Crab Nebula
Green Bank Radio Telescope
Hydrogen 21cm Image of the Milky Way 14
Very Large Array

15. 9 May 2006
Radio Frequency Antennas and Applications
(Looking Down)
Space Shuttle Radar
Topography Mission
Satellite Radar image of
rainfall intensity in Katrina
SRTM image of the Crater
Highlands region of
Tanzania
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16. 9 May 2006
Specialty Antennas for Communications
Mars Rover High Gain
Phased Array Antenna
Backpack antennas
Conformal
Antenna for
Aircraft Phased Array Antenna for
the Navy
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