The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth
The design, development, application, and capabilities of a variable frequency microwave radiometer are described. This radiometer demonstrated the versatility, accuracy, and stability required to provide contributions to the geophysical understanding of ocean and ice processes. A closed-loop feedba...
Main Author: | |
---|---|
Format: | Other/Unknown Material |
Language: | unknown |
Published: |
1980
|
Subjects: | |
Online Access: | http://hdl.handle.net/2060/19800020136 |
id |
ftnasantrs:oai:casi.ntrs.nasa.gov:19800020136 |
---|---|
record_format |
openpolar |
spelling |
ftnasantrs:oai:casi.ntrs.nasa.gov:19800020136 2023-05-15T18:18:29+02:00 The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth Harrington, R. F. Unclassified, Unlimited, Publicly available Jun 1, 1980 application/pdf http://hdl.handle.net/2060/19800020136 unknown Document ID: 19800020136 Accession ID: 80N28637 http://hdl.handle.net/2060/19800020136 No Copyright CASI ELECTRONICS AND ELECTRICAL ENGINEERING NASA-TM-81847 1980 ftnasantrs 2019-07-21T10:35:48Z The design, development, application, and capabilities of a variable frequency microwave radiometer are described. This radiometer demonstrated the versatility, accuracy, and stability required to provide contributions to the geophysical understanding of ocean and ice processes. A closed-loop feedback method was used, whereby noise pulses were added to the received electromagnetic radiation to achieve a null balance in a Dicke switched radiometer. Stability was achieved through the use of a constant temperature enclosure around the low loss microwave front end. The Dicke reference temperature was maintained to an absolute accuracy of 0.1 K using a closed-loop proportional temperature controller. A microprocessor based digital controller operates the radiometer and records the data on computer compatible tapes. This radiometer exhibits an absolute accuracy of better than 0.5 K when the sensitivity is 0.1 K. The sensitivity varies between 0.0125 K and 1.25 K depending upon the bandwidth and integration time selected by the digital controller. Remote sensing experiments were conducted from an aircraft platform and the first radiometeric mapping of an ocean polar front; exploratory experiments to measure the thickness of lake ice; first discrimination between first year and multiyear ice below 10 GHz; and the first known measurements of frequency sensitive characteristics of sea ice. Other/Unknown Material Sea ice NASA Technical Reports Server (NTRS) |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
ELECTRONICS AND ELECTRICAL ENGINEERING |
spellingShingle |
ELECTRONICS AND ELECTRICAL ENGINEERING Harrington, R. F. The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
topic_facet |
ELECTRONICS AND ELECTRICAL ENGINEERING |
description |
The design, development, application, and capabilities of a variable frequency microwave radiometer are described. This radiometer demonstrated the versatility, accuracy, and stability required to provide contributions to the geophysical understanding of ocean and ice processes. A closed-loop feedback method was used, whereby noise pulses were added to the received electromagnetic radiation to achieve a null balance in a Dicke switched radiometer. Stability was achieved through the use of a constant temperature enclosure around the low loss microwave front end. The Dicke reference temperature was maintained to an absolute accuracy of 0.1 K using a closed-loop proportional temperature controller. A microprocessor based digital controller operates the radiometer and records the data on computer compatible tapes. This radiometer exhibits an absolute accuracy of better than 0.5 K when the sensitivity is 0.1 K. The sensitivity varies between 0.0125 K and 1.25 K depending upon the bandwidth and integration time selected by the digital controller. Remote sensing experiments were conducted from an aircraft platform and the first radiometeric mapping of an ocean polar front; exploratory experiments to measure the thickness of lake ice; first discrimination between first year and multiyear ice below 10 GHz; and the first known measurements of frequency sensitive characteristics of sea ice. |
format |
Other/Unknown Material |
author |
Harrington, R. F. |
author_facet |
Harrington, R. F. |
author_sort |
Harrington, R. F. |
title |
The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
title_short |
The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
title_full |
The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
title_fullStr |
The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
title_full_unstemmed |
The development of a stepped frequency microwave radiometer and its application to remote sensing of the Earth |
title_sort |
development of a stepped frequency microwave radiometer and its application to remote sensing of the earth |
publishDate |
1980 |
url |
http://hdl.handle.net/2060/19800020136 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
CASI |
op_relation |
Document ID: 19800020136 Accession ID: 80N28637 http://hdl.handle.net/2060/19800020136 |
op_rights |
No Copyright |
_version_ |
1766195069999644672 |