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Atmospheric Radiation – Lecture 11
PHY2505 - Lecture 11
Principles of remote sensing
With thanks to Prof. K. Strong for lecture material
Selected figures from:
“Remote Sensing of the Lower Atmosphere” Graeme L. Stephens,
Oxford University Press (1994) ISBN 019-5081889
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Atmospheric Radiation – Lecture 11
Remote sensing definition
What do we mean by remote sensing?
a means of obtaining information about an object or medium without coming into contact with it
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Atmospheric Radiation – Lecture 11
Remote sensing definition
What do we mean by remote sensing?
a means of obtaining information about an object or medium without coming into contact with it
General: The acquisition and measurement of data/information on some property(ies) of a phenomenon, object, or material by a recording device not in physical, intimate contact with the feature(s) under surveillance; techniques involve amassing knowledge pertinent to environments by measuring force fields, electromagnetic radiation, or acoustic energy employing cameras, radiometers and scanners, lasers, radio frequency receivers, radar systems, sonar, thermal devices, seismographs, magnetometers, gravimeters, scintillometers, and other instruments.
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Atmospheric Radiation – Lecture 11
The inverse problem
Remote sensing is an INDIRECT METHOD that requires the solution of the inverse problem:
In simple terms:
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Atmospheric Radiation – Lecture 11
The inverse problem
-There is always the niggling doubt that you are actually measuring what you think you are and it is related to the thing you want to measure in the way you think!
In fact nearly all measurements are done in this way, but only in some fields is the possibility of error large enough to account for.
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Atmospheric Radiation – Lecture 11
Fundamental obstacles in the inverse problem
What are the three main problems associated with the inverse problem?
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Atmospheric Radiation – Lecture 11
Fundamental problems with the inverse problem
We will look at the inverse problem and weighting functions for particular measurement scenarios later,
FIRST…
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Atmospheric Radiation – Lecture 11
Classification of remote sensing methods
Source of radiationType of measurements
Spectral region
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Atmospheric Radiation – Lecture 11
Active & Passive methods
Source of radiationType of measurements
Spectral region
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Atmospheric Radiation – Lecture 11
Four passive imaging techniques
Eg. The Mars Imager for Cloud and Aerosol