A Demonstration Test of the Modular Automated Weather System (MAWS)
A Demonstration Test of the Modular Automated Weather System (MAWS)

Author: Donald A. Chisholm

Publisher:

Published: 1980

Total Pages: 90

ISBN-13:

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A microprocessor-based automated airfield weather observing and forecasting system called MAWS (Modular Automated Weather System) was developed to demonstrate the feasibility of modernizing many of the observing and forecasting functions performed in operational base weather stations. Scott Air Force Base, Illinois, was chosen as the demonstration site and operations were conducted from January 1977 through January 1979. Weather sensors at five observation sites around the airfields were polled several times each minute, the data transmitted over commercial, voice-grade telephone lines to a central supervisory microprocessor where the data were suitably collated, averaged and formatted for display on alpha-numeric display devices at key locations and for magnetic tape archiving for post analysis. The demonstration confirmed that modernized weather support can be largely achieved with state-of-the-art, commercially available hardware/software. Such a system would be compatible with other automation efforts in civilian weather services and other C-cubed efforts in the DOD. The advantage of spatially and temporally detailed weather information in marginal and adverse situations was documented. Sensor siting considerations were addressed in relation to specific weather elements and observational requirements. The contributions of automated met watch procedures and short-range guidance forecasts of RVR landing minima were demonstrated. Feedback on system performance and acceptability was obtained from cognizant AWS offices.

An Automated Cloud Observation System (ACOS)
An Automated Cloud Observation System (ACOS)

Author: Edward B. Geisler

Publisher:

Published: 1980

Total Pages: 32

ISBN-13:

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Analysis of cloud base height data collected during a seven-month period from a three Rotating Beam Ceilometer (RBC) network on Otis AFB, Massachusetts, demonstrated the accuracy of an automated cloud observation system. The high degree of correspondence between the automated and human observations of cloud height, low cloud amount, multiple cloud layers, and ceiling confirms the accuracy of the hierarchical clustering technique when applied to a network of RBC's confined to the immediate environs of an airfield. Tests demonstrated only slight improvements in automated cloud observation are realized by incorporating additional information from a second and third RBC on or near an airfield.

A Digital Processing and Display System for the Rotating Beam Ceilometer (AN/GMQ-13)
A Digital Processing and Display System for the Rotating Beam Ceilometer (AN/GMQ-13)

Author: James Weyman

Publisher:

Published: 1981

Total Pages: 76

ISBN-13:

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A microprocessor-based automated display system for the Rotating Beam Ceilometer (RBC) was developed to demonstrate the feasibility of modernizing and improving the present display system. The new system consists of a Burroughs self-scan panel display (model number SSD0124-0039) and an Intel 8080A-based microcomputer. The program acquires the signal returns from the RBC, converts the analog signal to a digital value, and displays the most recent scan. The system allows for three modes of operation or processing. Two modes, a one-scan mode and a five-scan mode, require no further inputs from the user once they have been selected. A manual mode which is user-interactive is also available. The basic display capabilities consist of a depiction of signal intensity vs. height, a numerical display of the height of the peak value and an illuminated cursor positioned at the peak value. Evaluation of the system at AFGL and Scott AFB, IL has confirmed that the display is more readable, provides more accurate cloud heights and permits better interpretation of the data obtained than does the current CRT display system. Further considerations which will be incorporated before operational implementation are discussed. (Author).

Automation of Visual Weather Observations
Automation of Visual Weather Observations

Author: H. Albert Brown

Publisher:

Published: 1980

Total Pages: 38

ISBN-13:

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A study was performed to determine the feasibility of objectively and automatically determining two key components of an aviation weather observation: present weather and obstruction to vision. The automated system utilized was an instrumented tower and surface array of sensors located at the AFGL Weather Test Facility (WTF), Otis AFB, Massachusetts. The objective method consisted of a decision-tree program (AUTO) based on several uniquely different responses by these weather sensors to the same weather phenomena and on discrimination techniques using tower and surface instrument comparison. The ability of AUTO to monitor rapidly changing weather events and to discriminate different types of weather is demonstrated through selected hourly periods of observations taken at 1-min intervals. Hourly observations generated over a 14-month period, March 1978 through April 1979, are compared with FAA observations to determine the effectiveness of AUTO. Major areas of agreement were found in the discrimination of fog, haze, snow, rain, and no weather. Final results show that the FAA observations of the existence and non-existence of obstructions to vision and present weather were duplicated in 82 and 86% of the cases. Thus the acquisition of real weather for an aviation weather observation, a duty presently performed by a human observer, is obtainable through an objective decision-tree program using an automated sensor array. (Author).

Accessions List
Accessions List

Author: Environmental Science Information Center. Library and Information Services Division

Publisher:

Published: 1981

Total Pages: 96

ISBN-13:

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An Automated Low Cloud Prediction System
An Automated Low Cloud Prediction System

Author: Edward B. Geisler

Publisher:

Published: 1981

Total Pages: 44

ISBN-13:

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At the Air Force Geophysics Laboratory (AFGL) Weather Test Facility (WTF) at Otis AFB, MA, a network of cloud base height, visibility, and wind measuring instruments were used to explore techniques for the short range prediction of low cloud ceiling. AFGL developed this system in response to the USAF Air Weather Service's requirements to modernize its basic weather support capabilities. This system allowed AFGL to evaluate the ability of statistical forecasting techniques to provide decision assistance significantly improved over the decision assistance currently provided by climatology and persistence. The approach relies upon the use of a hierarchical clustering algorithm to transform the raw cloud base height data into an automated low cloud observation. Four prediction techniques (Regression Estimation of Event Probabilities, Equivalent Markov, climatology, and persistence) yielding probability estimates of low cloud ceiling were evaluated and comparisons made to determine their respective accuracy and reliability. In addition, thresholding techniques were used to convert probability forecasts (unit bias, maximum probability, iterative, and persistence). Analysis of the data collected at the AFGL WTF demonstrates the accuracy and reliability of the automated low cloud prediction system. Regression estimation of event probabilities provided accurate, reliable, high resolution probability forecasts with results superior to climatology, persistence, and Equivalent Markov.