Comparison of areal extent of snow as determined by AVHRR and SSM/I satellite imagery
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Authors
Maxson, Robert W.
Subjects
AVHRR
Imagery
Satellite
SSM/I
Snow
Imagery
Satellite
SSM/I
Snow
Advisors
Durkee, Philip A.
Date of Issue
1992-09
Date
September 1992
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Advanced Very High Resolution Radiometric (AVHRR) and Special Sensor Microwave imager (SSM/I) imagery are compared to determine the areal extent of snow. A multi-spectral AVHRR algorithm, utilizing channels 1 (0.6 um), 2 8.76 um), 3 (3.7 um) and 4 (11.0 um), creates a synthetic image that classifies land, snow, water and clouds. The classified images created by this algorithm serve as a baseline for a second algorithms that examines spatially and temporally matched SSM/I imagery. The SSM/I separation algorithm uses the 85 GHz horizontally polarized channel as well as the 37 GHz horizontally and vertically polarized channels. The synthetic image created by this algorithm classifies land, snow and water. Both separation algorithms use empirically derived separation thresholds obtained from bi-spectral scatter plots. Separation is made at a given pixel location based on the radiative identity assigned to that location from various wavelength combinations. The AVHRR data provides high resolution, daytime images of the snow pack but is completely dependent on the absence of clouds to view this ground based feature. The SSM/I data gives lower resolution imagery of the snow during daylight or night time satellite passes and is not affected by the presence of non-precipitating clouds. A total of 12 sub scenes are analyzed using both data sets and general agreement of the two sets of imagery is established.
Type
Thesis
Description
Series/Report No
Department
Meteorology
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funder
Format
99 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.