Method for interferometric radar measurement

• US 20050128126A1
• Filed: 02/03/2004
• Published: 06/16/2005
• Est. Priority Date: 01/21/1999
• Status: Active Grant

• Current Assignee: EADS Deutschland GmbH (Airbus SE)
• Original Assignee: EADS Deutschland GmbH (Airbus SE)
• Inventors: Klausing, Helmut, Wolframm, Aribert P.
• Granted Patent: US 7,002,508 B2
• Time in Patent Office: Days
• US Class Current: 342/25.R
• CPC Class Codes: G01S 13/9023 combined with interferometric techniques
• CPC Class Codes: G01S 13/9082 Rotating SAR [ROSAR]
• CPC Class Codes: G01S 13/9092 combined with monopulse techniques

Abstract

It is proposed in connection with a method for the interferometric radar measurement in conjunction with a helicopter operating in accordance with the ROSAR principle (Heli-Radar) that two coherent receiving antennas with receiving channels are associated with a transmitter of the ROSAR-system mounted on the revolving rotary cross; and that the difference (ΔR) between the two distances (R+ΔR, R) from the measured impact point P are calculated, in the manner known per se, based on the wavelength λ of the emitted radar signal and the measured phase difference of the receiving echo of the two coherent receive channels.

Claims

1. An arrangement for interferometric radar measurement comprising:

a transmitter disposed on a turnstile of a ROSAR system of a helicopter radar;

at least two assigned coherent receiving antennas having receiving channels disposed on said turnstile of said ROSAR system of a helicopter radar; and

an additional transmitting/receiving antenna disposed on said turnstile wherein said additional transmitting/receiving antenna has a narrow beam and is focused downward in elevation covering a lower range of a sight angle.

2. The arrangement for interferometric radar measurement according to claim 1, wherein said transmitter and said at least two assigned coherent receiving antennas are arranged at an end of said turnstile.

3. The arrangement for interferometric radar measurement according to claim 1, wherein said receiving antennas are positioned vertically over each other in a normal position of a helicopter.

4. A process for interferometric radar measurement comprising the steps of:

assigning two coherent receiving antennas having receiving channels to a transmitter;

calculating a path length difference of two distances to a measured receiving point from a wave length of a transmitted radar signal and of a measured phase difference of a reception echo of both coherent receiving channels;

assigning said two coherent receiving antennas to a transmitter of a ROSAR system;

arranging said two coherent receiving antennas and said transmitter on a rotating turnstile of a radar; and

evaluating signals of an additional transmitting/receiving antenna that has a narrow beam and is for determination of said phase difference of said reception echo of both coherent receiving channels;

wherein a helicopter operating according to the ROSAR principle is used for the interferometric radar measurement.

5. The method according to claim 4, further comprising a step of calculating coordinates of a respective receiving point using a sight angle for representing image points on an integrated graphic display screen in the ROSAR system.

6. The method according to claim 5, wherein said antenna and a center of an image on said graphic display screen are in a fixed relationship.