Author: Thomas J. Keegan
Publisher:
ISBN:
Category : Cloud forecasting
Languages : en
Pages : 24
Book Description
The first step in an investigation of the use of satellite imagery data in automated short-range forecasts of clouds and precipitation is to examine the variation in ground brightness under clear-sky conditions. Bedford, Massachusetts, Albany, New York, Pittsburgh, Pennsylvania, and Dulles International Airport, Virginia, were selected as test sites for the period March to December 1977. Data were corrected for error and noise. Navigation was fine-tuned to an accuracy of 1 to 2 pixels. Average, standard deviation, maximum, minimum and range of brightness were computed over a range of area sizes around each station in order to establish a stable sample size. The statistics stabilized by a 5 x 5 pixel area. Although the number of cases was small, necessitating combining stations, the correlation between brightness and sun angle was high. The slope of the regression curve between these variables was steeper in spring and fall than in summer. Additional data are needed, but it is expected that they will refine rather than revise significantly the present results. (Author).
Variation in Ground Brightness Over Northeastern United States as Sensed by GOES Satellites
Author: Thomas J. Keegan
Publisher:
ISBN:
Category : Cloud forecasting
Languages : en
Pages : 24
Book Description
The first step in an investigation of the use of satellite imagery data in automated short-range forecasts of clouds and precipitation is to examine the variation in ground brightness under clear-sky conditions. Bedford, Massachusetts, Albany, New York, Pittsburgh, Pennsylvania, and Dulles International Airport, Virginia, were selected as test sites for the period March to December 1977. Data were corrected for error and noise. Navigation was fine-tuned to an accuracy of 1 to 2 pixels. Average, standard deviation, maximum, minimum and range of brightness were computed over a range of area sizes around each station in order to establish a stable sample size. The statistics stabilized by a 5 x 5 pixel area. Although the number of cases was small, necessitating combining stations, the correlation between brightness and sun angle was high. The slope of the regression curve between these variables was steeper in spring and fall than in summer. Additional data are needed, but it is expected that they will refine rather than revise significantly the present results. (Author).
Publisher:
ISBN:
Category : Cloud forecasting
Languages : en
Pages : 24
Book Description
The first step in an investigation of the use of satellite imagery data in automated short-range forecasts of clouds and precipitation is to examine the variation in ground brightness under clear-sky conditions. Bedford, Massachusetts, Albany, New York, Pittsburgh, Pennsylvania, and Dulles International Airport, Virginia, were selected as test sites for the period March to December 1977. Data were corrected for error and noise. Navigation was fine-tuned to an accuracy of 1 to 2 pixels. Average, standard deviation, maximum, minimum and range of brightness were computed over a range of area sizes around each station in order to establish a stable sample size. The statistics stabilized by a 5 x 5 pixel area. Although the number of cases was small, necessitating combining stations, the correlation between brightness and sun angle was high. The slope of the regression curve between these variables was steeper in spring and fall than in summer. Additional data are needed, but it is expected that they will refine rather than revise significantly the present results. (Author).
Scientific and Technical Aerospace Reports
Specification of Cloud Amount Over Local Areas from GOES Visual Imagery
Author: Thomas J. Keegan
Publisher:
ISBN:
Category : Clouds
Languages : en
Pages : 68
Book Description
Publisher:
ISBN:
Category : Clouds
Languages : en
Pages : 68
Book Description
Development of Techniques to Specify Cloudiness and Rainfall Rate Using GOES Imagery Data
Author: H. Stuart Muench
Publisher:
ISBN:
Category : Cloud forecasting
Languages : en
Pages : 52
Book Description
This report summarizes the work accomplished during the first phase of an investigation concerning methods of introducing digitized satellite imagery into short-range, objective forecasting operations. The data archive being assembled for this study is described, with particular attention given to the steps taken to maximize the accuracy of the satellite imagery. These steps included 'fine tuning' the navigation and selecting procedures for 'normalizing' the data by correcting for the effects of Lambertian and anisotropic scattering. Consistency of the data, spatial and temporal, was tested by analysis of ground reflectance during cloudless days, and a pilot test of the specification of single layers of clouds was conducted. Both of these tests gave encouraging results. An investigation of specifying precipitation rate, using just the visible reflectance and infrared temperature of the cloud top, also produced good results. Nomograms for the average rate during the hour following the satellite observation, as well as for the probability of observing more than 0.01 in. and 0.10 in. of precipitation, are illustrated. Two appendices present the geometrical and optical equations relevant to the investigation. (Author).
Publisher:
ISBN:
Category : Cloud forecasting
Languages : en
Pages : 52
Book Description
This report summarizes the work accomplished during the first phase of an investigation concerning methods of introducing digitized satellite imagery into short-range, objective forecasting operations. The data archive being assembled for this study is described, with particular attention given to the steps taken to maximize the accuracy of the satellite imagery. These steps included 'fine tuning' the navigation and selecting procedures for 'normalizing' the data by correcting for the effects of Lambertian and anisotropic scattering. Consistency of the data, spatial and temporal, was tested by analysis of ground reflectance during cloudless days, and a pilot test of the specification of single layers of clouds was conducted. Both of these tests gave encouraging results. An investigation of specifying precipitation rate, using just the visible reflectance and infrared temperature of the cloud top, also produced good results. Nomograms for the average rate during the hour following the satellite observation, as well as for the probability of observing more than 0.01 in. and 0.10 in. of precipitation, are illustrated. Two appendices present the geometrical and optical equations relevant to the investigation. (Author).
Technical Abstract Bulletin
Report on Research at AFCRL.
Author: Air Force Cambridge Research Laboratories (U.S.)
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 228
Book Description
Publisher:
ISBN:
Category : Geophysics
Languages : en
Pages : 228
Book Description
R & D Abstracts
Author: Technology Reports Centre (Great Britain)
Publisher:
ISBN:
Category :
Languages : en
Pages : 570
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 570
Book Description
Accessions List
Author: Environmental Science Information Center. Library and Information Services Division
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 96
Book Description
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 96
Book Description
Meteorological and Geoastrophysical Abstracts
Earth Resources
Author:
Publisher:
ISBN:
Category : Astronautics in earth sciences
Languages : en
Pages : 758
Book Description
Publisher:
ISBN:
Category : Astronautics in earth sciences
Languages : en
Pages : 758
Book Description