Accession Number:

ADA278958

Title:

The Polygon-Ellipse Method of Data Compression of Weather Maps

Descriptive Note:

Project rept.

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

• Gertz, J. L.

Report Date:

1994-03-28

Pagination or Media Count:

82.0

Abstract:

Providing an accurate picture of the weather conditions in the pilots area of interest could be a highly useful application for ground-to-air data links. The problem with using data links to transmit weather pictures is the large number of bits required to exactly specify a weather image. To make transmission of weather maps practical, a means must be found to compress this image. The Polygon-Ellipse PE encoding algorithm developed in this report represents weather regions as ellipses, polygons, and exact patterns. The actual ellipse and polygon parameters are encoded and transmitted the decoder algorithm redraws the shape from their encoded parameter values and fills in the included weather pixels. Special coding techniques are used in PE to compress the encoding of the shape parameters to achieve further overall compression. The PE algorithm contains procedures for gracefully degrading the fidelity of the transmitted image when necessary to meet a specified bit limit. Pictorial examples of the operation of this algorithm on both Terminal Doppler Weather Radar TDWR and ASR-9 radar-generated weather images are presented. Data compression, Weather images, Weather transmission, Data link

Descriptors:

• *IMAGE PROCESSING
• *DATA COMPRESSION
• *DATA LINKS
• *METEOROLOGICAL CHARTS
• COMPUTER PROGRAMS
• ALGORITHMS
• OPTIMIZATION
• PARAMETERS
• SHAPE
• METEOROLOGICAL RADAR
• REGIONS
• CODING
• PATTERNS
• MAPS
• SURFACE TO AIR
• DECODERS
• POLYGONS
• ELLIPSES
• WEATHER COMMUNICATIONS

Subject Categories:

• Meteorology
• Computer Programming and Software
• Telemetry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE