LOCATION SYSTEM FOR A FLYING CRAFT

• US 20140028486A1
• Filed: 09/09/2012
• Published: 01/30/2014
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: CORNIC, Pascal, GARREC, Patrick, ARTIS, Jean-Paul
• Granted Patent: US 9,348,011 B2
• Time in Patent Office: Days
• US Class Current: 342/38
• CPC Class Codes: F41G 7/301 Details
• CPC Class Codes: F41G 7/305 for spin-stabilized missiles
• CPC Class Codes: G01S 1/14 using amplitude comparison of signals transmitted simultaneously from antennas or antenna systems having differently oriented overlapping directivity-characteristics
• CPC Class Codes: G01S 5/0247 Determining attitude

Abstract

A location and guidance system including a flying craft and a reception device. The flying craft includes a plurality of antennas distributed around its fuselage and emitting rearwards with rectilinear polarization, the emitted signals being specific to each antenna, the positions and the dimensions of the antennas being configured such that the body of the flying craft avoids by masking for at least one antenna the reflections of the signal emitted by this antenna off the ground or off lateral obstacles whatever the position of the flying craft. The reception device is placed substantially on a trajectory axis of the flying craft and configured to be oriented to sight the rear thereof and includes at least two single-pulse antennas operating in orthogonal planes determines a position of the flying craft by analysing the emitted signals received by the antennas of the reception device.

Claims

1. A location and guidance system comprising:

a flying craft comprising a plurality of antennas distributed around a fuselage of the flying craft and configured to emit signals rearwards from the flying craft with rectilinear polarization, with the emitted signals being specific to each antenna, wherein the positions and the dimensions of the antennas being configured such that the body of the flying craft avoids by masking for at least a first one of the antennas reflections of the signal emitted by the first antenna off the ground or off lateral obstacles whatever the position of the flying craft; and

a reception device placed substantially on a trajectory axis of the flying craft and configured to be oriented to sight a rear of the flying craft, the reception device comprising

a plurality of single-pulse antennas operating in orthogonal planes, and

means for determining a position of the flying craft by analysing the emitted signals received by the antennas of the reception device.

2. The system according to claim 1, wherein the flying craft further comprises a modulation control circuit is configured to generate the emitted signals such that the reception device is able to identify and process, separately, the emitted signals specific to each antenna.

3. The system according to claim 1, wherein the flying craft further configures a waveform generator which delivers a sinusoidal signal to each of the antennas of the flying craft sequentially and in a periodic manner on a different frequency.

4. The system according to claim 3, wherein a dead emission time S is contrived periodically so as to allow the synchronization of a reception device.

5. A flying craft comprising a plurality of antennas distributed around a fuselage of the flying craft and configured to emit signals rearwards from the flying craft with rectilinear polarization, the emitted signals being specific to each antenna, the positions and the dimensions of the antennas being configured such that the body of the flying craft avoids by masking for at least a first one of the antennas reflections of the signal emitted by the first antenna off the ground or off lateral obstacles whatever the position of the flying craft.

6. The flying craft according to claim 5, wherein the antennas are embodied on the basis of rectilinear microwave leakage lines, and are disposed substantially perpendicular to the fuselage of the flying craft.

7. The flying craft according to claim 5, further comprising fins serving to guide the flying craft, wherein the antennas are fixed to the fins.

8. A reception device comprising:

a plurality of single-pulse antennas pointed in a same direction of sighting and operating in orthogonal planes; and

means for identifying and processing, separately, signals received from respective antennas of a flying craft according to claim 5, such that signals emitted by separate antennas are identified and processed separately, and for automatically detecting and rejecting received signals disturbed by reflections.

9. The reception device according to claim 8, further comprising:

two reception chains, each chain comprising;

a frequency-controlled coherent reference oscillator,

low noise amplifiers,

filters,

a mixer,

analogue-digital conversion means,

means of signal coding and processing based on an FFT fast Fourier transform; and

common processing means shared by the two chains.

10. The reception device according to claim 8, wherein an angular location in elevation and in bearing is determined by two-plane single-pulse deviometry on the basis of the signals received from the antennas of the flying craft.

11. The reception device according to claim 8, wherein the reception device is configured to measure a Doppler frequency for each of the signals received from the antennas of the flying craft, and is configured to determine a distance traversed by the flying craft by temporal integration of the measured Doppler frequencies.

12. The reception device according to claim 8, wherein the reception device is configured to estimate a value of roll of the flying craft and a rate of the roll by measuring an amplitude of a signal received on two orthogonal rectilinear polarizations.

13. The reception device according to claim 8, wherein the reception device is configured to identify rejected signals by verifying an amplitude coherence of the received signals received over time.

14. The reception device according to claim 8, further comprising a plurality of identical antennas of like polarization, disposed at two different heights, used for reception, wherein the reception device is configured to reject measurements corresponding to signals of different amplitudes received simultaneously on the identical antennas.

15. The reception device according to claim 8, wherein the plurality of antennas consists of four antennas, including two antennas with vertical polarization, distributed at different heights, and allowing elevation measurement, and including two other antennas having horizontal polarization and distributed on a horizontal plane to allow bearing measurement.

16. The reception device according to claim 8, wherein the reception device position is situated substantially at ground level, and the reception device is fixed or mobile.

17. The reception device according to claim 8, wherein the reception device is located onboard an aircraft.