Storage and transmission of compressed weather maps and the like

• US 5,363,107 A
• Filed: 07/16/1993
• Issued: 11/08/1994
• Est. Priority Date: 07/16/1993
• Status: Expired due to Fees

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Grappel, Robert D., Gertz, Jeffrey L.
• Primary Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US08/093,161
• Time in Patent Office: 480 Days
• Field of Search: 342/26, 342/58, 395/114
• US Class Current: 342/26.00B
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: G01W 1/10 Devices for predicting weather conditions computers per se G06; display devices G09

Abstract

Representing weather data with elliptical or polygonal representations for transmission or reception. Ellipseticity may be determined, vertex coordinates may be shuffled, or polygons may be continuously fillable or filled based on filling flag values. Sides may be replaced within the polygonal representations. Certain storage requirements or transmission orders may be variable.

Claims

1. A method of displaying weather patterns on a display, including:

receiving an encoded signal representing weather data produced by weather radar, said weather data including polygon perimeter information and an indication that indicates whether said polygon perimeter information includes a series of shuffled vertex coordinates having varying storage requirements and uniquely defining a polygon, and

in response to an indication that said polygon perimeter information includes said series of shuffled vertex coordinates, determining from said series of vertex coordinates the positions of the sides of the shuffled polygon, and

displaying the polygon on the display.

2. The method of claim 1 wherein said step of receiving receives the shuffled vertex coordinates organized in pairs of two coordinate types and wherein the shuffled vertex coordinates of one of said types are encoded with varying length storage requirements.

3. The method of claim 1 wherein said step of receiving receives the shuffled vertex coordinates organized in pairs of two coordinate types and wherein shuffled vertex coordinates of one of said types are encoded with varying length storage requirements, said one of said coordinate types having a range for said polygon, said series of shuffled vertex coordinates starting with the pairs of coordinates in said range having the highest and lowest values in said range of said one of said coordinate types.

4. A method of displaying weather patterns on a display, including:

receiving an encoded signal representing weather data produced by weather radar, said weather data including polygon perimeter information and an indication that indicates whether said polygon perimeter information represents a continuous segment fillable polygon,

in response to an indication that said polygon perimeter information represents a continuous segment fillable polygon, filling said polygon with a series of parallel non-colinear continuous line segments, and

wherein said indication distinguishes between a plurality of types of continuous segment fillable polygons, and wherein said step of filling fills said polygons with a series of said segments oriented in a manner corresponding to the type indicated in the indication received in said step of receiving.

5. The method of claim 4 wherein said types include horizontally-fillable and vertically-fillable polygons.

6. A method of transmitting weather maps, including:

receiving weather data produced by weather radar defining weather regions,

generating a polygonal representation of one of said weather regions,

for a set of two vertices defining the ends of a sequence of three sides of the polygonal representation, determining the position of a new vertex that defines, in combination with the set of two vertices, two replacement sides for the sequence, the position of the vertex minimizing a measure of change in area of the polygonal representation when the three sides are replaced with the two replacement sides,

determining the position of further new vertices for further sets of two vertices,

replacing the sequence of three sides corresponding to the one of the new vertices that results in the lowest level of the measure of change in area with the two replacement sides corresponding to said one of the new vertices, and

transmitting the polygonal representation that includes said one of the new vertices over a communications channel.

7. The method of claim 6 wherein the measure of change in area is an approximation determined by the areas of triangles defined by the three sides and the two replacement sides.

8. The method of claim 6 wherein the step of determining the position of the new vertex differs depending on which of a convex, concave, and convex-concave shapes the three sides define.

9. A method of transmitting weather maps produced by weather radar, comprising:

representing a series of regions within the weather maps as elliptical approximations of the weather regions, each said elliptical approximation having a plurality of parameters of a plurality of types defining the elliptical representation,

representing some of the parameters of one of the types with shorter signal lengths than other of the parameters of the same type, and

transmitting parameters of the elliptical representations in an order dependent on the values of the parameters of the elliptical representation.

10. A method of displaying weather maps produced by weather radar on a display, comprising:

receiving a signal stream including a series of signals of differing lengths, said signals defining a series of elliptical approximations each representing a region within the weather map, each said elliptical approximation having a plurality of parameters of a plurality of types defining the elliptical approximation,

delimiting the signals from the signal stream based on values of previously received parameters from the signal stream, and

displaying said elliptical approximations based on the signals defining said elliptical approximations.

11. The method of claim 10 wherein the step of delimiting parameters is based on a distance parameter, which is the distance from the first focus to any point on the boundary and then on to the second focus, for that elliptical approximation.

12. The method of claim 10 wherein the step of delimiting parameters is based on the value of a coordinate of two focuses of each of the elliptical representations.

13. A method of transmitting weather maps produced by weather radar, comprising:

receiving weather data including weather regions, said weather regions having an area and a plurality of moments of inertia, and

measuring the ellipseticity of weather regions defined by said weather data by comparing said moments of inertia of each said region with said area of each said region,

determining whether to represent each said region with a signal including an elliptical approximation or with a signal representing another type of representation based on said step of measuring, and

transmitting one of said signals, based on said step of determining, over a communications channel.