CN103713286A - High-resolution radio altimeter with positioning function and method for measuring position - Google Patents

Abstract

The invention discloses a high-resolution radio altimeter with a positioning function. The high-resolution radio altimeter mainly solves the problem that an existing altimeter can only measure the height of an aircraft and cannot position the aircraft. The altimeter comprises three pairs of antennas, an emitter, three receivers, three analog-digital (A/D) converters, three storages, a distance processing channel, a distance processor, a phase processing channel, a phase processor and a height position processor. The first pair of the antennas is used for both receiving and emitting, the second and the third pairs of the antennas are used for receiving, received signals of the second pair of the antennas are processed sequentially through the distance processing channel and the distance processor to obtain a target slope distance r, the received signals of the three pairs of the antennas are sequentially processed by the phase processing channel and the phase processor to obtain a target interference angle theta, and the height position processor carries out data processing on the interference angle theta, the slope distance r and speed and posture information provided by an inertial navigation system to obtain a position coordinate (X,Y,Z) of a target and the height H of the aircraft. The high-resolution radio altimeter can measure the height of the aircraft and the position of a ground reflection point at the same time and can assist in navigation.

Description

There is the high-resolution radio altimeter of positioning function and the method for measuring position

Technical field

The invention belongs to electronic instrument technology field, a kind of radio altimeter, can be used for the aircraft carriers such as survey aircraft apart from height and the position on ground specifically.

Background technology

At present, aircraft needs navigator that the information such as orientation, speed, distance of aircraft is provided in flight course, for self-position location and flight path correction, conventional navigational system has radar Doppler navigational system, inertial navigation system, satellite navigation system, images match navigational system etc., wherein images match navigational system is to utilize Terrain Elevation sensor to mate and position with electronics elevation map, can also provide the terrain feature of aircraft below to be used for forward direction crashproof and evade landform danger.The terrain feature of the aircraft height that images match navigational system is required and aircraft below, the terrain feature that the aircraft height normally providing by radio altimeter obtains in conjunction with airborne Interference synthetic aperture radar INSAR realizes independent navigation.

Radio altimeter is to carry on aircraft for the device of measuring height, and it is mainly used in the navigation of aircraft.Current radio altimeter adopts two antennas conventionally, an emitting antenna, a receiving antenna, this height indicator can only be measured the height on the relative ground of aircraft, and its landform resolving power is determined by beam angle, fire pulse width or signal bandwidth, therefore landform resolving power is poor, and altimetry precision is not high, cannot obtain the terrain feature of aircraft below, can not position aircraft, can only, by coordinating with carry-on miscellaneous equipment, complete conventional navigation.For example, 265 radio altimeters that 782 factories produce, fire pulse width is 100ns, beam angle is ± 20 °, and at 1000m height, Terrain resolution is 173m * 173m, emissive power: 47dBm～50dBm, inferior cun of profile: 190mm * 150mm * 96mm, weight 3.5kg, is exactly the radio altimeter of this function.

Airborne Interference synthetic aperture radar INSAR can obtain the terrain feature of aircraft below, and it is to utilize two secondary receiving antennas, then carries out separately synthetic aperture imaging, then two sub-pictures are carried out to the fluctuating height that registration process can obtain full wafer landform.The volume of interference synthetic aperture radar is large, Heavy Weight, cost are high, and operand is large, algorithm more complicated, these effects limit it on medium and small unmanned plane or guided missile, use.

Above-mentioned traditional height indicator landform resolving power is low, cannot position, and interference synthetic aperture radar is because cost is high, volume is not greatly suitable for installing and using of middle-size and small-size aircraft yet.

Summary of the invention

The object of the invention is to the deficiency for above-mentioned prior art, a kind of have the high-resolution radio altimeter of positioning function and the method for measuring position are proposed, with improve radio altimeter industrial resolution, reduce its volume and weight, reduce costs, make it meet medium and small unmanned plane and missile-borne request for utilization.

Technical scheme of the present invention is achieved in that

A high-resolution radio altimeter one, with positioning function, comprising: antenna, receiver, analog-digital conversion a/d, storer and signal processing unit, is characterized in that:

Antenna adopts three pairs, and the first slave antenna 1a is as duplexer, and the second slave antenna 1b, the 3rd slave antenna 1c be as receiving antenna, the corresponding receiver of every slave antenna;

Signal processing unit comprises: apart from treatment channel 6, apart from processor 8, Phase Processing passage 5, Phase Processing device 7 and height and position processor 9;

Described apart from treatment channel 6, for the echo signal of intermediate frequency that the second slave antenna is received, become base band Doppler continuous wave signal, and this base band Doppler continuous wave signal is exported to apart from processor 8;

Described apart from processor 8, for the signal of the treatment channel output of adjusting the distance, carry out successively level processing, signal to noise ratio (S/N ratio) judgement and apart from ambiguity solution, obtain the oblique distance r of target, and this oblique distance is exported to height and position processor 9;

Described Phase Processing passage 5, for by the echo signal of intermediate frequency of three width antenna receptions, becomes respectively three roadbed band Doppler continuous wave signals, and this three roadbeds band Doppler continuous wave signal is exported to Phase Processing device 7;

Described Phase Processing device 7, for the signal of Phase Processing passage output is carried out to phase-detection, Used for Unwrapping Phase Ambiguity successively, obtains the interference angle θ of target, and this interference angle is exported to height and position processor 9;

Described height and position processor 9, speed and attitude information that being used for the interference angle θ that Phase Processing device 7 is exported, the target oblique distance r exporting apart from processor 8 and inertial navigation system 11 provides carry out data processing, obtain position coordinates (X, Y, Z) and the aircraft height H of target.

Two, utilization has a method for positioning function high-resolution radio altimeter measuring position, comprises the steps:

1) after signal modulation pulse producer 13 being produced, by the first slave antenna 1a, launch earthward;

2) echoed signal three secondary receiving antennas being received separately becomes intermediate-freuqncy signal after receiver is processed, and Jiang San road intermediate-freuqncy signal is given respectively analog-digital conversion a/d module and carried out digitized sampling, and Bing Jiang tri-tunnel sampled signals are given memory stores;

3) echo signal of intermediate frequency the second slave antenna 1b in storer being received export to apart from treatment channel 6 be correlated with, correlation filtering, mixing and band filtering processes and becomes base band Doppler signal, and export to apart from processor 8;

4) echo signal of intermediate frequency that in storer, three slave antennas receive is exported to Phase Processing passage 5, echo signal of intermediate frequency to every slave antenna is all correlated with, correlation filtering, mixing and band filtering are processed, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to Phase Processing device 7;

5) the base band Doppler signal apart from 8 pairs of inputs of processor carries out successively level detection, signal to noise ratio (S/N ratio) judgement and obtains target oblique distance r apart from ambiguity solution, and exports to height and position processor 9;

6) processing of phase-detection, solution phase ambiguity is all carried out on each road of 7 pairs of three roadbed band Doppler signals of Phase Processing device, obtains the interference angle θ of target, and exports to height and position processor 9;

7) velocity (V that height and position processor 9 provides interference angle θ, the oblique distance r of input, inertial navigation system 10 _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft:

Y＝rcosθ

$Z=(-b\±\sqrt{b^2-4\mathrm{ac}})/\left(2a\right)$

$X=\sqrt{{\left(r\sin \mathrm{\θ}\right)}^2-Z^2}$

H＝Z

In formula: $a=1+\frac{V_z^2}{4V_x^2},b=-A{V}_z\·\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos \mathrm{\β}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\β}\right)}^2}-{\left(r\sin \mathrm{\θ}\right)}^2,$

$A=\frac{{\left(V_{x}r\cos \mathrm{\β}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\β}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\β}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\θ}\right)}^2-{\left(r\sin \mathrm{\β}\right)}^2,$

the angle between oblique distance and aircraft speed, f _dfor Doppler frequency, λ is emission wavelength.

The present invention has the following advantages:

1, high-resolution radio altimeter of the present invention is by carrying out band division to horizontal and vertical, not only can measure the height of aircraft, can also measure ground return and put the position of relative aircraft, if again the terrain section line forming in tracking target process is mated with digital elevation topomap, can complete independent navigation.

2, resolution is high, operand is little, cost is low, lightweight, volume is little.

The present invention utilizes Doppler and interference technique to carry out the terrain feature of explorer vehicle below, and the signal of narrow Doppler's band is processed and can be realized high resolution; In baseband I/Q frequency mixer, data are carried out to sample process, greatly reduced operand; System forms simple, and available dsp chip carries out high speed processing, has reduced cost, weight and volume.

3, the present invention utilizes triantennary principle of interference solution phase ambiguity method simple, adopts triple channel to carry out range search simultaneously, has improved search efficiency.

Accompanying drawing explanation

Fig. 1 is rang ring and Doppler's band schematic diagram of present level table echoed signal;

Fig. 2 is height indicator system chart of the present invention;

Fig. 3 is the reception echoed signal schematic diagram of three slave antennas in system of the present invention;

Fig. 4 is Phase Processing passage and apart from the composition frame chart for the treatment of channel in system of the present invention;

Fig. 5 is quadrature I/Q base band mixer block diagram in system of the present invention;

Fig. 6 is Phase Processing device block diagram in system of the present invention;

Fig. 7 is system middle distance processor block diagram of the present invention;

Fig. 8 is the workflow diagram of system middle distance processor of the present invention;

Fig. 9 is the method flow diagram of height indicator measuring position in system of the present invention.

Embodiment

Below by the drawings and specific embodiments, further illustrate embodiment of the present invention.

As shown in Figure 1, the distance of the relative aircraft of rang ring a of existing height indicator echoed signal is r, and the frequency of Doppler's band b is 0, and the frequency of Doppler's band c is f1.When the present invention processes the ground echo receiving, the position of range gate is made as to r, band filter center frequency is made as f1, just can obtain the echoed signal of target, and this signal is processed just can unique position of determining selected target.

With reference to Fig. 2, system of the present invention comprises: three secondary receiving antennas, three receivers, three A/D modules, three storeies, Phase Processing passage 5, apart from treatment channel 6, Phase Processing device 7, apart from processor 8, height and position processor 9, inertial navigation system 10, clock oscillator 11, code generator 12, pulse producer 13, phase-modulator 14, transmit-receive switch 15 with apart from control gate 16;

Described three secondary receiving antennas are respectively the first slave antenna 1a, the second slave antenna 1a and the 3rd slave antenna 1c, three receivers are respectively the first receiver 2a, the second receiver 2b and the 3rd receiver 2c, three A/D modules are respectively an A/D module 3a, the 2nd A/D module 3b and the 3rd A/D module 3c, and three storeies are respectively first memory 4a, second memory 4b and the 3rd storer 4c;

Described the first slave antenna 1a is as duplexer, it exports to the first receiver 2a by the radiofrequency signal receiving, the first receiver 2a exports to an A/D module 3a after radiofrequency signal is become to intermediate-freuqncy signal, the one A/D module 3a exports to first memory 4a after the intermediate-freuqncy signal of input is sampled with sample frequency 200MHz, and first memory 4a exports to Phase Processing passage 5 after input signal is stored; The second slave antenna 1b is as receiving antenna, it exports to the second receiver 2b by the radiofrequency signal receiving, the second receiver 2b exports to the 2nd A/D module 3b after radiofrequency signal is become to intermediate-freuqncy signal, the 2nd A/D module 3b exports to second memory 4b by the intermediate-freuqncy signal of input with after sample frequency 200MHz sampling, and second memory 4b exports to respectively Phase Processing passage 5 after to input signal storage and apart from treatment channel 6; The 3rd slave antenna 1c is as receiving antenna, it exports to the 3rd receiver 2c by the radiofrequency signal receiving, the 3rd receiver 2c exports to the 3rd A/D module 3c after this radiofrequency signal is become to intermediate-freuqncy signal, the 3rd A/D module 3c exports to the 3rd storer 4c after the intermediate-freuqncy signal of input is sampled with sample frequency 200MHz, and the 3rd storer 4c exports to respectively Phase Processing passage 5 after input signal is stored;

Described clock oscillator 11 produces an excitation and exports to yard generator 12, code generator 12 is received the rear Barker code signal that produces 13 of excitation and is exported to phase-modulator 14, the pulse signal that pulse generator 13 produces is also exported to phase-modulator 14, phase-modulator 14 is exported to transmit-receive switch 15 by obtaining phase-coded signal after the symbol signal of input and pulse signal modulation, and transmit-receive switch 15 is launched input signal earthward through the first slave antenna 1a;

Described Phase Processing passage 5, its three inputs are respectively the echoed signal of first memory 4a, second memory 4b, the 3rd storer 4c output, Phase Processing passage 5 Jiang San road input signals become three roadbed band signals after processing respectively, and this three roadbeds band signal is all exported to Phase Processing device 7, Phase Processing device 7 Jiang San road input signals obtain the interference angle θ of target after processing respectively, and this interference angle θ is exported to height and position processor 9;

Described distance treatment channel 6, its three inputs are respectively in storer 4b three not echoed signals in the same time, apart from passage 6 respectively Dui San road input signal after processing, obtain three roadbed band signals and all export to apart from processor 8, after processing apart from 8 pairs of input signals of processor, obtain the oblique distance r of target, and this oblique distance is exported to height and position processor 9, this oblique distance r movement apart from control gate 16 as FEEDBACK CONTROL simultaneously;

Described height and position processor 9, carries out data processing by speed, the attitude angle information of target oblique distance r, the interference angle θ of input, aircraft that inertial navigation system 10 provides, obtains the position coordinates (X, Y, Z) of target and the height H of aircraft.

With reference to Fig. 3, three secondary receiving antennas of height indicator of the present invention are positioned on straight line, and this straight line is vertical with the flight track of aircraft.When between any two slave antennas, spacing is larger, the target echo signal phase differential that they receive can produce phase ambiguity, by this three slave antenna, can solve the problem of above-mentioned phase ambiguity, and by the long baseline between the first slave antenna 1a and the 3rd slave antenna 1c, phase place be carried out to accurate measurement.5 pairs of three slave antenna echoes of Phase Processing device are separated the interference angle θ that can obtain target after phase ambiguity is processed, height indicator system just can be determined the position coordinates (X of target according to the oblique distance r of target, interference angle θ, speed and attitude angle information, Y, Z) and the height H of aircraft, target is the peak in selected Doppler's band.

With reference to Fig. 4, Phase Processing passage 5 of the present invention comprises: correlator 51, correlation filter 52, baseband I/Q frequency mixer 53 and bar band filter 54.

Correlator 51, the intermediate-freuqncy signal of input is carried out relevant to the local code signal that code generator 12 produces, and export to correlation filter 52, correlation filter 52 carries out the filtering of intermediate frequency band by the pulse signal of correlator 51 outputs and becomes continuous wave signal, and exports to base band quadrature I/Q frequency mixer 53; Base band quadrature I/Q frequency mixer 53, carries out successively 90 ° of phase shifts, mixing, low-pass filtering and data pick-up by the intermediate-freuqncy signal of correlation filter 52 outputs and processes, and makes its baseband signal that becomes positive frequency, and exports to bar band filter 54; Bar band filter 54, carries out band filtering by the baseband signal of the positive frequency of input, leaches the Doppler signal in selected Doppler's band, and suppresses the signal of other frequencies.

Middle distance treatment channel 6 structures of the present invention are identical with the structure of Phase Processing passage 5, and this two passage is worked simultaneously.

With reference to Fig. 5, baseband I/Q frequency mixer 53 of the present invention comprises: two frequency mixer, two low-pass filters, two withdrawal devices, two phase shifters and a difference unit 539; Described two frequency mixer are respectively the first frequency mixer 532 and the second frequency mixer 533, described two low-pass filters are respectively the first low-pass filter 534 and the second low-pass filter 535, described two withdrawal devices are respectively the first withdrawal device 536 and the second withdrawal device 537, and described two phase shifters are respectively the first phase shifter 531 and the second phase shifter 538.

The first frequency mixer 532, the intermediate-freuqncy signal of intermediate-frequency filter 52 outputs is become to baseband signal, and export to the first low-pass filter 534, the first low-pass filter 534 carries out the baseband signal of input to export to the first withdrawal device 536 after low-pass filtering, the first withdrawal device 536 extracts input signal, and the signal after extracting is exported to difference unit 539;

The first phase shifter 531 carries out the intermediate-freuqncy signal of intermediate-frequency filter 52 outputs to export to the second frequency mixer 533 after 90 ° of phase shifts, the second frequency mixer 533 becomes baseband signal by input intermediate-freuqncy signal and exports to the second low-pass filter 535, the second low-pass filter carries out input signal to export to the second withdrawal device 537 after low-pass filtering, the second withdrawal device 537 is exported to the second phase shifter 538, the second phase shifters and input signal is carried out to 90 ° is exported to difference unit 539 after shifting to after input signal is extracted;

Difference unit 539 carries out the first withdrawal device 536 output signals and the second phase-shifter 538 output signals to obtain the base band Doppler signal of positive frequency after difference, and exports to bar band filter 54.

With reference to Fig. 6, Phase Processing device 7 of the present invention comprises: three phase detectors and Used for Unwrapping Phase Ambiguity unit 77, i.e. first-phase bit detector 74, second-phase bit detector 75 and third phase bit detector 76.

First-phase bit detector 74, carries out phase bit comparison by the echoed signal 71 of the first slave antenna and the echoed signal of the second slave antenna 72 of input, obtains two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Second-phase bit detector 75, carries out phase bit comparison by the echoed signal 72 of the second slave antenna and the echoed signal of the 3rd slave antenna 73 of input, obtains two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Third phase bit detector 76, carries out phase bit comparison by the echoed signal 71 of the first slave antenna and the echoed signal of the 3rd slave antenna 73 of input, obtains two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit 77; Used for Unwrapping Phase Ambiguity unit 77, separates phase ambiguity by three phase differential of three phase detectors outputs and processes, and obtains the interference angle θ of target.

With reference to Fig. 7, of the present inventionly apart from processor 8, comprise: level processor 84, signal to noise ratio (S/N ratio) judge module 85 and apart from processing unit 86; This is provided with three input signals apart from processor, is respectively the first input signal 81, the second input signal 82 and the 3rd input signal 83 apart from treatment channel 6 outputs.

Level processor 84, the first input signal 81, the second input signal 82 and the 3rd input signal 83 are carried out respectively to level and process signal power and the noise power that obtains three signals, calculate the signal to noise ratio (S/N ratio) of three signals, and signal to noise ratio (S/N ratio) maximum in three is exported to signal to noise ratio (S/N ratio) judge module 85; Signal to noise ratio (S/N ratio) judge module 85, compares the signal-noise ratio threshold of the signal to noise ratio (S/N ratio) of input and setting, and comparative result is exported to apart from processing unit 86, as an input apart from processing unit 86;

Apart from processing unit 86, also have other three input signals, be respectively the first input signal 81, the second input signal 82 and the 3rd input signal 83, apart from 86 pairs of these the first input signals 81 of processing unit, the second input signal 82 and the 3rd input signal 83 find master, the range value of secondary lobe is divided by and obtains principal subsidiary lobe ratio, and principal subsidiary lobe ratio maximum in three and the principal subsidiary lobe ratio of setting are carried out to the comparison of secondary thresholding, if be more all greater than for twice, set thresholding, think and capture target, input signal is carried out processing apart from ambiguity solution the oblique distance r that obtains target, and this oblique distance is fed back to apart from control gate 16, target is followed the tracks of, if thresholding relatively occurs being less than while setting thresholding situation, think and do not capture target, continue target to search for.

This principle of work apart from processor 8 as described in Figure 8, that is:

(1) parameter is carried out to initialization, counter K=0 is set, ripple door moving step length τ ₀equal a chip lengths, search initial time is t ₀, duty is search, signal-noise ratio threshold is Thr ₁, principal subsidiary lobe is Thr than thresholding ₂;

(2), by producing three ripple doors apart from control gate 16, early pulse, intermediate wave door, late pulse, make ripple door benchmark T=t constantly ₀+ 3K τ ₀, when duty is search, it is T that early pulse initial time is set ₁=T-τ ₀, intermediate wave door initial time is T ₂=T, late pulse initial time is T ₃=T+ τ ₀; When duty is tracking, it is T that early pulse initial time is set ₁=T-τ ₀2, intermediate wave door initial time is T ₂=T, late pulse initial time T ₃=T+ τ ₀the length of/2, three ripple doors is pulse width;

(3) three ripple doors are chosen the second slave antenna echo, by choosing San road echoed signal, all carry out the signal to noise ratio (S/N ratio) that level processing obtains three signals, and snr value and signal-noise ratio threshold maximum in three signals are compared; If signal to noise ratio (S/N ratio) is less than thresholding Thr ₁, counter K=K+1 is set, execution step (2) is searched for next time, if signal to noise ratio (S/N ratio) is greater than thresholding Thr ₁perform step (4);

(4) the principal subsidiary lobe ratio of the echoed signal of three ripple doors being chosen carries out thresholding judgement for the second time, if maximum principal subsidiary lobe ratio is less than setting thresholding Thr in three signals ₂, thinking and do not capture target, counter K=K+1 is set, and execution step (2) is searched for next time; If being greater than, maximum principal subsidiary lobe ratio sets thresholding Thr ₂, think and capture target, the signal of three Bo Mennei is carried out obtaining target oblique distance r apart from ambiguity solution execution step (5);

(5) duty is become to tracking from search, and K=K+ (2r/C-T is set ₂)/(3 τ ₀), C is the light velocity, then repeating step (2) carries out the distance tracking of next cycle.

With reference to Fig. 9, the method with systematic survey of the present invention target location, comprises the steps:

Step 1, launches earthward by the first slave antenna 1a after the signal modulation that pulse producer 13 is produced;

Step 2, the echoed signal that three secondary receiving antennas are received separately becomes intermediate-freuqncy signal after receiver is processed, and Jiang San road intermediate-freuqncy signal is given respectively analog-digital conversion a/d module and is carried out digitized sampling, and Bing Jiang tri-tunnel sampled signals are given respectively memory stores;

Step 3, the echo signal of intermediate frequency that the second slave antenna 1b is received export to apart from treatment channel 6 be correlated with, correlation filtering, mixing and band filtering processes and becomes base band Doppler signal, and export to apart from processor 8;

Step 4, the echo signal of intermediate frequency that three slave antennas are received is exported to Phase Processing passage 5, echo signal of intermediate frequency to every slave antenna is all correlated with, correlation filtering, mixing and band filtering are processed, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to Phase Processing device 7;

Step 5, carries out successively level detection, signal to noise ratio (S/N ratio) judgement and obtains target oblique distance r apart from ambiguity solution apart from the base band Doppler signal of 8 pairs of inputs of processor, and exporting to height and position processor 9.

Step 6, each road of 7 pairs of three roadbed band Doppler signals of Phase Processing device is all carried out phase-detection, is separated the processing of phase ambiguity, obtains the interference angle θ of target, and exports to height and position processor 9;

Step 7, height and position processor 9 is by oblique distance r, the velocity (V that inertial navigation system 10 provides of the interference angle θ of step 6 output, step 5 output _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft.

(7a), by target oblique distance r and interference angle θ, obtain target ordinate Y:

Y＝rcosθ； <1>

(7b), by target oblique distance r and interference angle θ, the interference equation of a circle that obtains target is:

X ²+Z ²＝(rsinθ) ²；<2>

(7c) by target oblique distance r and velocity (Vx, V _y, Vz), obtain target Doppler equation of a circle and be:

${(X-\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+{(Z-\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2={\left(r\sin \mathrm{\&beta;}\right)}^2,---<3>$

In formula

be the angle between oblique distance and aircraft speed, fd is Doppler frequency, and λ is emission wavelength;

(7d) will in the ordinate Y in step (7a), step (7b), interfere equation of a circle to combine and solve an equation with Doppler equation in step (7c), obtain the vertical coordinate Z of target and the horizontal ordinate X of target:

By formula <1> and formula <2> substitution formula <3>, and arrange:

$2\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}}X+2\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}}Z=\frac{{\left(V_{x}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(r\sin \right)}^2---<4>$

Order $A=\frac{{\left(V_{x}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(r\sin \mathrm{\&beta;}\right)}^2,$

After being arranged, formula <4> becomes:

$2\frac{V_{x}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+{V_y}^2+{y_z}^2}}X+2\frac{V_{z}r\cos \mathrm{\&beta;}}{\sqrt{{V_x}^2+{V_y}^2+{V_z}^2}}Z=A---<5>$

$X=\frac{A\sqrt{V_x^2+V_y^2+V_z^2}}{2V_{x}r\cos \mathrm{\&beta;}}-\frac{V_{z}Z}{2V_x};---\left(6\right)$

The horizontal ordinate X substitution formula <2> of target in formula <6> can be obtained:

${(\frac{A\sqrt{V_x^2+V_y^2+V_z^2}}{2V_{x}r\cos \mathrm{\&beta;}}-\frac{V_{z}Z}{2V_x})}^2+Z^2={\left(r\sin \mathrm{\&theta;}\right)}^2,---<7>$

Formula <7> is arranged and is obtained:

$(1+\frac{V_z^2}{4V_x^2})Z^2-{\mathrm{AV}}_z\&CenterDot;\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos }Z+\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(r\sin \mathrm{\&theta;}\right)}^2=0---<8>$

Order $a=1+\frac{V_z^2}{4V_x^2},b=-{\mathrm{AV}}_2\&CenterDot;\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos \mathrm{\&beta;}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(r\sin \mathrm{\&theta;}\right)}^2,$

Formula <8> is arranged and is obtained:

aZ ²+bZ+c＝0 <9>

Solution formula <9> can obtain the vertical coordinate Z of target:

$Z=(-b\&PlusMinus;\sqrt{b^2-4\mathrm{ac}})/\left(2a\right);---<10>$

By the vertical coordinate Z substitution formula <2> of formula <10> target, can obtain the horizontal ordinate X of target:

(7e) height H of aircraft is:

H＝Z。<12>。

Claims (5)

1. a high-resolution radio altimeter with positioning function, comprising: antenna, receiver, analog-digital conversion a/d, storer and signal processing unit, is characterized in that:

Antenna adopts three pairs, and the first slave antenna (1a) is as duplexer, and the second slave antenna (1b), the 3rd slave antenna (1c) be as receiving antenna, the corresponding receiver of every slave antenna;

Signal processing unit comprises: apart from treatment channel (6), apart from processor (8), Phase Processing passage (5), Phase Processing device (7) and height and position processor (9);

Described apart from treatment channel (6), for the echo signal of intermediate frequency that the second slave antenna (1b) is received, become base band Doppler continuous wave signal, and this base band Doppler continuous wave signal is exported to apart from processor (8);

Described apart from processor (8), for the signal of the treatment channel output of adjusting the distance, carry out successively level processing, signal to noise ratio (S/N ratio) judgement and apart from ambiguity solution, obtain the oblique distance r of target, and this oblique distance is exported to height and position processor (10);

Described Phase Processing passage (5), for by the echo signal of intermediate frequency of three width antenna receptions, becomes respectively three roadbed band Doppler continuous wave signals, and this three roadbeds band Doppler continuous wave signal is exported to Phase Processing device (7);

Described Phase Processing device (7), for the signal of Phase Processing passage output is carried out to phase-detection, Used for Unwrapping Phase Ambiguity successively, obtains the interference angle θ of target, and this interference angle is exported to height and position processor (9);

Described height and position processor (9), speed and attitude information that being used for the interference angle θ that Phase Processing device (7) is exported, the target oblique distance r exporting apart from processor (8) and inertial navigation system (10) provides carry out data processing, obtain the position coordinates (X of target, Y, Z) and aircraft height H.

2. the high-resolution radio altimeter with positioning function according to claim 1, it is characterized in that working apart from treatment channel (6) and Phase Processing passage (5) simultaneously, and structure is identical, include: correlator (51), correlation filter (52), base band quadrature I/Q frequency mixer (53) and bar band filter (54);

Described correlator (51), relevant for the echoed signal of input and the local code signal of code generator transmitting are carried out, and export to correlation filter (52);

Described correlation filter (52), becomes continuous wave signal for the pulse signal of correlator output is carried out to the filtering of intermediate frequency band, and exports to base band quadrature I/Q frequency mixer (53);

Described base band quadrature I/Q frequency mixer (52), for carrying out successively phase shift 90 by the intermediate-freuqncy signal of correlation filter input ^°, mixing, low-pass filtering and data pick-up process, make its baseband signal that becomes positive frequency, and export to bar band filter (54);

Described band filter (54), for the baseband signal of the positive frequency of input is carried out to band filtering, leaches the Doppler signal in selected Doppler's band, and suppresses the signal of other frequencies.

3. the high-resolution radio altimeter with positioning function according to claim 1, is characterized in that comprising apart from processor (8): level processor (84), signal to noise ratio (S/N ratio) judge module (85) and apart from processing unit (86);

Described level processor (84), obtains signal power and noise power for input signal being carried out to level processing, calculates the signal to noise ratio (S/N ratio) of signal, and this signal to noise ratio (S/N ratio) is exported to signal to noise ratio (S/N ratio) judge module (85);

Described signal to noise ratio (S/N ratio) judge module (85), for the signal to noise ratio (S/N ratio) of input is compared with setting signal-noise ratio threshold, and exports to comparative result apart from processing unit (86);

Described apart from processing unit (86), for input signal is processed, obtain the oblique distance of target and realize the search of target or tracking, input signal is carried out to the comparison of secondary thresholding, if be more all greater than for twice, set thresholding, think and capture target, input signal is carried out processing apart from ambiguity solution the oblique distance r that obtains target, and this oblique distance is fed back to apart from control gate (16), target is followed the tracks of; If thresholding relatively occurs being less than while setting thresholding situation, think and do not capture target, continue target to search for.

4. the high-resolution radio altimeter with positioning function according to claim 1, is characterized in that Phase Processing device comprises: phase detectors (74), phase detectors (75), phase detectors (76) and Used for Unwrapping Phase Ambiguity unit (77);

Described phase detectors (74), for the echoed signal of the first slave antenna (1a) and the echoed signal of the second slave antenna (1b) of input are carried out to phase bit comparison, obtain two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit (77);

Described phase detectors (75), for the echoed signal of the second slave antenna (1b) and the echoed signal of the 3rd slave antenna (1c) of input are carried out to phase bit comparison, obtain two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit (77);

Described phase detectors (76), for the echoed signal of the first slave antenna (1a) and the echoed signal of the 3rd slave antenna (1c) of input are carried out to phase bit comparison, obtain two phase differential between input signal, and this phase differential is exported to Used for Unwrapping Phase Ambiguity unit (77);

Described Used for Unwrapping Phase Ambiguity unit (77), processes for three phase differential of three phase detectors outputs are separated to phase ambiguity, obtains the interference angle θ of target.

5. utilization has a method for the high-resolution radio altimeter measuring position of positioning function, comprises the steps:

1) after signal modulation pulse producer (13) being produced, by the first slave antenna (1a), launch earthward;

2) echoed signal three secondary receiving antennas being received separately becomes intermediate-freuqncy signal after receiver is processed, and Jiang San road intermediate-freuqncy signal is given respectively analog-digital conversion a/d module and carried out digitized sampling, and Bing Jiang tri-tunnel sampled signals are given memory stores;

3) echo signal of intermediate frequency the second slave antenna (1b) in storer being received export to apart from treatment channel (6) be correlated with, correlation filtering, mixing and band filtering processes and becomes base band Doppler signal, and export to apart from processor (8);

4) echo signal of intermediate frequency that in storer, three slave antennas receive is exported to Phase Processing passage (5), echo signal of intermediate frequency to every slave antenna is all correlated with, correlation filtering, mixing and band filtering are processed, become three roadbed band Doppler signals, and this three roadbeds band Doppler signal is exported to Phase Processing device (7);

5) apart from processor (8), the base band Doppler signal of input carried out successively level detection, signal to noise ratio (S/N ratio) judgement and obtains target oblique distance r apart from ambiguity solution, and exporting to height and position processor (9);

6) Phase Processing device (7) all carries out the processing of phase-detection, solution phase ambiguity to each road of three roadbed band Doppler signals, obtains the interference angle θ of target, and exports to height and position processor (9);

7) height and position processor (9) is by interference angle θ, the oblique distance r of input, velocity (V that inertial navigation system provides _x, V _y, V _z) and attitude information carry out data processing, obtain the position coordinates (X, Y, Z) of target and the height H of aircraft:

Y=rcosθ

$Z=(-b\&PlusMinus;\sqrt{b^2-4\mathrm{ac}})/\left(2a\right)$

$X=\sqrt{{\left(r\sin \mathrm{\&theta;}\right)}^2-Z^2}$

H=Z

In formula: $a=1+\frac{V_z^2}{4V_x^2},b=-A{V}_z\&CenterDot;\frac{\sqrt{V_x^2+V_y^2+V_z^2}}{2V_x^{2}r\cos \mathrm{\&beta;}},c=\frac{A^2(V_x^2+V_y^2+V_z^2)}{{\left(2V_{x}r\cos \mathrm{\&beta;}\right)}^2}-{\left(r\sin \mathrm{\&theta;}\right)}^2,$

$A=\frac{{\left(V_{x}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{(Y-\frac{V_{y}r\cos \mathrm{\&beta;}}{\sqrt{V_x^2+V_y^2+V_z^2}})}^2+\frac{{\left(V_{z}r\cos \mathrm{\&beta;}\right)}^2}{V_x^2+V_y^2+V_z^2}+{\left(r\sin \mathrm{\&theta;}\right)}^2-{\left(r\sin \mathrm{\&beta;}\right)}^2,$

the angle between oblique distance and aircraft speed, f _dfor Doppler frequency, λ is emission wavelength.

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