METHOD OF CORRECTING REFLECTIVITY MEASUREMENTS BY ISOTHERM DETECTION AND RADAR IMPLEMENTING THE METHOD

• US 20120139779A1
• Filed: 05/31/2011
• Published: 06/07/2012
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: PUJOL, Olivier, COSTES, Clémentine, ARTIS, Jean-Paul, MESNARD, Frédéric, SAUVAGEOT, Henri, IASSAMEN, Alia
• Granted Patent: US 8,659,468 B2
• Time in Patent Office: Days
• US Class Current: 342/26.B
• CPC Class Codes: G01S 13/953 mounted on aircraft
• CPC Class Codes: G01S 13/958 Theoretical aspects
• CPC Class Codes: G01S 7/411 Identification of targets based on measurements of radar reflectivity G01S7/415 takes precedence
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A method of correcting the reflectivity measurements performed by a radar such as a weather radar, a reflectivity measurement being associated with a resolution volume includes analyzing the current resolution volume to determine whether the plane representing the 0° C. isotherm passes through it. When the plane representing the 0° C. isotherm passes through the current resolution volume, the volume is split into two parts lying on either side of said plane, the attenuation associated with the resolution volume is determined by taking into account the contribution of each of the parts to the measured reflectivity. The reflectivity associated with the current resolution volume is corrected using the attenuation thus determined. An onboard weather radar implements the method.

Claims

1. A method of correcting a reflectivity measurement performed by a radar such as a weather radar, the reflectivity measurement being associated with a resolution volume, the method comprising:

analyzing the current resolution volume to determine whether the plane representing the 0°

C. isotherm passes through the resolution volume;

when the plane representing the 0°

C. isotherm passes through the current resolution volume, dividing said resolution volume into two portions lying on either side of said plane, and determining an attenuation associated with the resolution volume by taking into account the contribution of each of the portions to measured reflectivity; and

correcting the reflectivity associated with the current resolution volume using the attenuation thus determined;

2. The method according to claim 1, wherein the attenuation for precipitation, is determined using the equation

k=a×

(1−

α

)^b×

(Z_m)^b+a′

×

α

×

(Z_m)^b′

in which

Z_m represents the measured reflectivity of a resolution volume V_r expressed in mm⁶×

m<sup>−

3</sup>,

α

represents the fraction of the resolution volume lying above the 0°

C. isotherm and

a, b, a′

, b′

are real constants to be chosen according to the weather conditions and the type of precipitation.

3. A weather radar onboard an aircraft, implementing the method according to claim 1.