JPH0972957A - Altitude calculation system by three-dimensional radar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of an altitude data of the same airplane acquired by a plurality of three-dimensional radars. SOLUTION: A radar measured altitude processing part 121A of a three- dimensional altitude processing section 12A sets a radar measured altitude utilizing a radar data 301 and a weighted value corresponding to the reliability of quality in distance information is set from the distance information and the type of the radar to be applied to a sub track and the results are stored into a track data storing section 2A. The sub track thus obtained gives information on an altitude provided with a quality of data set from variations in the updated frequency of the radar data 301. A system measured altitude processing section 122A reads out the stored information from the track data storing section 2A and selects a plurality of sub tracks by adding a selection by the weighted value, besides the conventional selections made from the quality of the sub track, the type of the radar and the sub track as reference respectively. Thus, a weighted average processing having the weighted value as weight is applied to the sub tracks selected to calculate a system measured altitude at a high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aircraft altitude calculation method using a three-dimensional radar, and in particular, it utilizes a plurality of altitude data for the same aircraft acquired by a plurality of three-dimensional radars and is used to represent the altitude of the aircraft. It relates to an aircraft altitude calculation method using a three-dimensional radar that accurately determines the system measurement altitude as a value.

[0002]

2. Description of the Related Art Based on a plurality of altitude data obtained from radar data on the same aircraft captured by a plurality of three-dimensional radars, a system measured altitude as a representative value of these altitude data is calculated and used for target position evaluation. It

FIG. 2 is a block diagram showing the configuration of a conventional aircraft altitude calculation method using a three-dimensional radar. The configuration of the conventional example shown in FIG. 2 includes a track tracking device 1 that performs a process related to track tracking of an aircraft, and a track data storage unit 2 that writes and reads process data of the track tracking device 1.
In addition, a plurality of three-dimensional radars 101, 102, ..., 10N and two aircrafts A201 and B202 are shown together.

The track tracking device 1 tracks a track while evaluating the position of a target aircraft and displays the track in a predetermined format, and a plurality of three-dimensional radars 101, 102 ,.
A three-dimensional altitude processing unit 12 that calculates a representative altitude of a target aircraft based on the radar data 301 acquired in 10N.

The three-dimensional altitude processing unit 12 is a radar measurement altitude processing unit 121 for setting and processing sub-tracks, which are time-series data as altitude information in consideration of data quality for the same target captured by a plurality of three-dimensional radars, The radar measurement altitude processing unit 121 includes a system measurement altitude processing unit 122 that calculates a system measurement altitude as a measurement altitude representing the altitude acquired by a plurality of three-dimensional radars based on the sub-track information set and processed.

Next, the operation of the conventional aircraft altitude calculation method using the three-dimensional radar shown in FIG. 2 will be described. Aircraft A2
The radar data 301 obtained by the radars 101 and 102 for 01 and B202 are supplied to the track tracking processing unit 11 and the three-dimensional altitude processing unit 12 of the track tracking device 1.
The track tracking processing unit 11 sets and displays a target aircraft track based on the radar data 301 and the system measurement altitude provided from the three-dimensional altitude processing unit 12.

The radar measurement altitude processing unit 121 of the three-dimensional altitude processing unit 12 determines the radar measurement altitude setting circuit 1211 for determining the radar measurement altitude of the captured aircraft based on the radar data 301 and the error dispersion of the radar measurement altitude. An error variance estimation value setting circuit 1212 for setting an estimation value and a sub-track quality state setting circuit 1213 for setting the quality state of the sub-track as altitude information to which the quality based on the update frequency of the acquired data is added are provided.

The radar measurement altitude setting circuit 1211 of the radar measurement altitude processing unit 121 obtains the radar measurement altitude for the same aircraft based on the altitude data obtained in time series of the radar data 301. Error variance estimation value setting circuit 1212
Is for both the present error calculated by a linear expression that sets the system altitude error set in advance for each three-dimensional radar based on the system type and a plurality of previous errors,
An error variance estimation value is set by multiplying both by a predetermined ratio determined by taking into account the performance different for each radar and averaging them. The error variance estimation value thus estimated is supplied to the sub track quality state setting circuit 1213.

The sub track quality state setting circuit 1213 determines whether the radar measurement altitude for each aircraft read from the track data storage unit 2 is updated based on new data, that is, the number of hits of radar data acquisition. A quality standard that indicates the reliability of radar measurement altitude data is set in advance, and time-series data for a specified measurement time of radar measurement altitude that includes quality information classified based on this quality standard is used as a sub-track. The error variance estimation value described above is added to the track data storage unit 2 together with the respective quality states set by the quality standard.

The system measurement altitude processing unit 122 includes a sub track quality state base selection circuit 1221 for selecting a sub track whose sub track quality state exceeds a predetermined level and a radar type base selection circuit for selecting a sub track according to a radar type. 12
22 and a reference sub-track base selection circuit 1223 that performs selection based on the reference sub-track set comprehensively for the sub-track
And a system measurement altitude calculation circuit 1224 for calculating the system measurement altitude.

The sub track quality state base selection circuit 1221 is
The sub track quality state for each captured aircraft set by the radar measurement altitude processing unit 121 is read from the track data storage unit 2, and the sub track whose sub track quality state exceeds a predetermined selection level is selected. The radar type base selection circuit 1222 selects a sub-track that exceeds the selection level set based on the quality of the sub-track that the radar type brings.

The reference sub-track base selection circuit 1223 selects a sub-track that exceeds the comprehensive reference sub-track selection level set including the quality state and the radar type as a candidate for selecting the representative sub-track. All selected sub-tracks that exceed the above-mentioned reference sub-track selection level are candidates as candidates. The system measurement altitude calculation circuit 1224 targets all the sub-tracks selected by the reference sub-track base selection circuit 1223, and performs an averaging process using the error variance estimation values given to these sub-tracks as weighted values to obtain a system. Calculate the measured altitude.

[0013]

In the above-described conventional aircraft altitude calculation method using the three-dimensional radar, the selection criterion for selecting the sub-track as the source of the system measurement altitude calculation from a plurality of candidate sub-tracks is as follows. Selection criteria based on the distance between the aircraft and each 3D radar are not included. Next, conventional selection criteria will be shown. Conventional selection criteria (1) Sub-track quality: The frequency of updating new period data is used as an evaluation index for quality assessment. (2) Radar type: It is an index of selection based on performance specifications that differ depending on the radar type.

In the first place, the radar measurement altitude accuracy is a function of the distance between the radar and the aircraft, and this conventional selection criterion for selecting the sub-track directly expresses the radar measurement altitude accuracy set for the sub-track. It is easy for the sub-tracks selected by these two selection criteria, not the selection scale, to contain low-accuracy ones, and avoid decreasing the calculated system measurement accuracy. There was a problem that I could not do it.

Further, in the conventional calculation of the system measurement altitude, the estimated value of the error variance obtained from the measurement error as a function of the distance of the radar of the transmission source corresponds to the weighting value for correction in the calculation of the system measurement altitude. It is given to the sub wake as something to do.

As described above, the error variance estimated value is obtained by averaging the values calculated from the linear equations preset for each three-dimensional radar by multiplying the previous values by the coefficient of a specific ratio. As it is, it represents the past state before the present time.

However, although the accuracy of the 3D radar measurement altitude depends more directly on the distance between the current 3D radar and the aircraft than on the past, a value expressing the past condition is used. Since it is used as a weighting value in the radar measurement altitude calculation in the calculation formula, there is a problem that the accuracy of the radar measurement altitude is unavoidably lowered.

An object of the present invention is to solve the above-mentioned problems, improve the evaluation index of the sub track quality of the conventional selection criterion in the system measurement altitude calculation, eliminate the selection of the sub track with low accuracy, and To provide an aircraft altitude calculation method using a three-dimensional radar with significantly improved calculation accuracy by improving the error variance estimation value, which is a weighted value depending on the radar type in the calculation of system measurement altitude, according to the current state. It is in.

[0019]

The present invention has the following means constitution in order to achieve the above-mentioned object. That is, the altitude calculation method using the three-dimensional radar of the present invention evaluates the frequency of updating radar data for each of a plurality of radar measured altitudes set based on radar data of the same target aircraft captured by a plurality of three-dimensional radars. Altitude by 3D radar that sets a plurality of sub-tracks that give the radar measurement altitude the magnitude of quality reliability as an index and selects a representative sub-track from these sub-tracks and outputs it as the system measurement altitude Calculation method, multiple 3
Each three-dimensional radar contributes to the measurement value of different distance information R acquired for the same target aircraft, and sets variable elements of n (n is a natural number) items common to each three-dimensional radar N-th order expression of the distance information R expressing the variation included in the information R P ₀ + P ₁ · R + R ₂ · R ² + ... +
The reciprocal of P _n · R ⁿ (P ₀ , P ₁ , P ₂ , ..., P _n is a constant set based on the type of each three-dimensional radar) is used to indicate the quality of the radar measurement altitude. Weighting value setting means set as a weighting value, and the weighting value is given to the sub-track for each of the plurality of three-dimensional radars set based on the altitude data of the radar data obtained in time series, and the quality state is set. And a sub-track quality state setting means for selecting the sub-track candidate for selecting the sub-track for calculating the system measurement altitude, the sub-track quality state, the type of the three-dimensional radar, and the sub-track as a reference. In addition to the selection condition based on the above, the one whose weight value assigned to the sub-track by the sub-track quality state setting means exceeds a predetermined reference value is selected as the sub-track to be used for the calculation of the system measurement altitude. Sub-track selection means including selection conditions to be selected, and a system for calculating the system altitude by weighted averaging the measured altitudes of the sub-tracks selected by the sub-track selection means with the weighted value as a weight. It has a structure provided with a measurement altitude calculating means.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention having the above structure will be described below. A radar system that deploys a plurality of three-dimensional radars to capture a target aircraft is operated as a radar system that quickly and accurately captures a plurality of targets. The altitude information of the target aircraft obtained by such a radar system uses the update frequency of the radar data as the evaluation scale for the radar measured altitude calculated based on the altitude data obtained independently in time series. Targeting sub-tracks with data reliability (data quality) information, the sub-tracks are given a predetermined weight to set the sub-track quality status, and further selected based on various selection criteria to select multiple altitudes. It is used as a system measurement altitude that represents information.

In the conventional three-dimensional radar altitude calculation method, the weights to be given to the sub-tracks are as follows:
The sub track setting condition itself does not include the condition related to distance information, and the weighting given to the sub track is also processed by simple one-dimensional processing proportional to the previous data and this data. The distance information included in the data is not reflected at all. Since the size and certainty of distance information have a great influence on the calculation of radar measurement altitude, it is inevitable that the calculation altitude of the conventional calculation method includes low quality.

According to the present invention, as the weight to be given to the sub-track, a weighting value is set which expresses the level of the sub-track quality reliability based on the latest distance information and the characteristics of each three-dimensional radar. When calculating the system measured altitude, the weighting average of multiple sub-tracks that are candidates for the above-mentioned weighting value is added to the conventional selection criteria to calculate the system measured altitude, thus ensuring the system measured altitude with significantly improved accuracy. Is possible.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention. In this embodiment, a track tracking device 1A that performs a process for tracking a target aircraft track, and a track tracking device 1A.
The track data storage unit 2A that stores the track data necessary for calculating the system measurement altitude of the tracking aircraft processed in step 2 for each target aircraft, and multiple radars 101, 102, ..., 10N, as well as aircraft A201, aircraft B202, and radar data 301 are also shown. And show it.

Further, the track tracking device 1A is provided with a track tracking processing section 11A for performing track tracking processing of a target aircraft and displaying a tracking track, and a three-dimensional altitude processing section 12A for calculating a system measurement altitude. Furthermore, the three-dimensional altitude processing unit 12
A is a radar measurement altitude processing unit that sets track data necessary for calculating system measurement altitude based on radar data.
121A and a system measurement altitude processing unit 122A that obtains a system measurement altitude based on the track data set by the radar measurement altitude processing unit 121A.

The radar measurement altitude processing unit 121A includes a radar measurement altitude setting circuit 1211, a weighting value setting circuit 1214 shown by a broken line which constitutes weighting value setting means, and a radar measurement altitude setting circuit 1211 together with a sub track quality state setting means. And a sub track quality state setting circuit 1215 shown by a broken line.

Further, the system measurement altitude processing section 122A is shown by a sub-track quality state base selection circuit 1221 constituting a sub-track selection means, a radar type base selection circuit 1222, a reference sub-track base selection circuit 1223, and a broken line. A weighting value base selection circuit 1225 and a system measurement altitude calculation circuit 1226 shown by a broken line which constitutes system measurement altitude calculation means are provided. In the configuration of the embodiment shown in FIG. 1, the portion indicated by the broken line is the portion directly related to the present invention, and the other portions have the same contents as the same reference numerals in FIG. Omit it.

FIG. 3 is a block diagram showing the structure of the aircraft altitude calculating apparatus using the three-dimensional radar shown in FIGS. 1 and 2 in comparison. The operation of the embodiment shown in FIG. 1 will be described below with reference to FIG. Radar measurement of 3D altitude processing unit 12A Radar measurement altitude setting circuit 1211 of altitude processing unit 121A
Calculates the altitude of the target aircraft based on the radar data 301 and uses it as the radar measurement altitude for the track data storage unit 2.
Remember in A. The weighting value setting circuit 1214 obtains the reciprocal of the n-th order formula of the power of the radar R included in the radar data 301 as a weighting value according to the following formula 1.

[0028]

[Equation 1] Weighting value = 1 / (P ₀ + P ₁ · R + P ₂ · R ² +
...... + P _n · R ⁿ )

The denominator of Equation 1 is a variation of n items common to each of the three-dimensional radars that contributes to the measured values of different distance information R obtained by each of the plurality of three-dimensional radars targeting the same target aircraft. It is an n-th order expression of R that expresses the magnitude of fluctuation included in the distance information R by setting an element, and the constants P ₀ , P ₁ , P ₂ , ..., P _n have positive and negative polarities. And varies depending on the type of 3D radar.

That is, the denominator of Expression 1 expresses the magnitude of the range of variation of the distance information for each type of three-dimensional radar, and the weighting value shown as the reciprocal of this corresponds to the quality reliability of the obtained distance information R. It becomes the selection weighting value to be given. The conventional weighting value is obtained by averaging the values calculated by the error variance estimation value setting circuit 1212 shown in FIG. 2 from the linear equation preset for each three-dimensional radar with the previous value at a specific ratio. As described above, is used as the error variance estimated value as the weighted value in the system measurement altitude calculation.

The sub-track quality state setting circuit 1215 sets the quality state, which is determined as the data quality reliability determination scale in the sub-track setting, to the sub-track by determining the size of the update frequency of new data for each three-dimensional radar, Data storage unit 2
Remember in A. From the radar measurement altitude processing unit 121A, the radar measurement altitude, the weight value replacing the conventional error variance estimation value, and the sub-track quality state are sent to and stored in the track data storage unit 2A as shown in FIG.

The sub track quality state base selection circuit 1221 of the system measurement altitude processing section 122A performs selection based on the sub track quality state. The radar type base selection circuit 1222 reads the sub track quality state from the track data storage unit 2A,
Make a selection based on the radar type. The reference sub-track base selection circuit 1223 performs selection based on the reference sub-track. The weighting value base selection circuit 1225 selects m pieces whose weighting values given by the weighting value setting circuit 1214 are equal to or more than a predetermined reference value to the selection output of the reference sub track base selection circuit 1223, and selects these from the system measurement altitude. It is stored in the track data storage unit 2A as a sub track used for calculation. The system measurement altitude calculation circuit 1226 reads the radar measurement altitude and the weight value from the track data storage unit 2A, and assigns the weight value assigned to each of the m sub-tracks selected by the weight value base selection circuit 1225. The weighted average processing shown in the following Equation 2 as a weight is performed to calculate the system measured altitude.

[0033]

[Equation 2] System measurement altitude = (H ₁ × m ₁ + H ₂ × m ₂
+ …… + H _m × m _m ) / (m ₁ + m ₂ + …… + m _m ) However, H ₁ , H ₂ ,… H _m : Radar measurement altitudes m ₁ , m ₂ ,… m _{m of} sub-track : Weight value

Thus, by calculating the system measurement altitude using the weighting value for altitude correction which reflects the influence of the distance data acquired by the radar, it is possible to calculate the system measurement altitude with extremely high accuracy.

[0035]

As described above, according to the present invention, the sub-track selection is weighted by the weighting value considering the influence of the distance information acquired for each three-dimensional radar, and the selection is added. Makes it possible to use sub-tracks with extremely high accuracy for calculating system-measured altitudes, which makes it possible to calculate highly-accurate system-measured altitudes considering distance information using the weighting values assigned to sub-tracks. Has the effect of being able to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an aircraft altitude calculation method using a three-dimensional radar according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional aircraft altitude calculation method using a three-dimensional radar.

FIG. 3 is a block diagram showing, in contrast, a configuration of an aircraft altitude calculation method by the three-dimensional radar in FIGS. 1 and 2.

[Explanation of symbols]

 1 Track tracking device 1A Track tracking device 2 Track data storage unit 2A Track data storage unit 11 Track tracking processing unit 11A Track tracking processing unit 12 3D altitude processing unit 12A 3D altitude processing unit 121 Radar measurement altitude processing unit 121A Radar measurement altitude Processing unit 122 System measurement altitude processing unit 122A System measurement altitude processing unit 1211 Radar measurement altitude setting circuit 1212 Error variance estimation value setting circuit 1213 Sub track quality status setting circuit 1214 Weight value setting circuit 1215 Sub track quality status selection circuit 1221 Sub track quality State base selection circuit 1222 Radar type base selection circuit 1223 Reference sub track base selection circuit 1224 System measurement altitude calculation circuit 1225 Weighted value base selection circuit 1226 System measurement altitude calculation circuit

Claims (1)

[Claims] 1. The radar measurement altitude is quality-reliable using the frequency of radar data update for each of a plurality of radar measurement altitudes set based on radar data of the same target aircraft captured by a plurality of three-dimensional radars. A three-dimensional radar altitude calculation method in which a plurality of sub-tracks are set and the representative sub-track is selected from these sub-tracks and output as the system measured altitude. Each three-dimensional radar contributes to the measurement value of different distance information R acquired for the same target aircraft, and sets variable elements of n (n is a natural number) items common to each three-dimensional radar The n-th order expression P ₀ of the distance information R expressing the variation included in the information R
+ P ₁ · R + R ₂ · R ² + …… + P _n · R ⁿ (P ₀ , P ₁ , P ₂ ,
, P _n is a reciprocal of a constant set based on the type of each three-dimensional radar) as a weighting value setting means for setting as a weighting value indicating the quality reliability of the radar measurement altitude, and a time series of radar data. Sub-track quality status setting means for assigning the weighted value to the sub-tracks for each of the plurality of three-dimensional radars set on the basis of the altitude data obtained in 1. and calculating the system measured altitude In addition to the selection condition based on the quality condition of the sub-track, the type of the three-dimensional radar and the reference sub-track, the sub-track quality condition setting means Includes a selection condition that selects a sub-track whose weighting value to be given to the sub-track exceeds a predetermined standard value as a sub-track to be used for system measurement altitude calculation The sub-track selection means and the system-measured altitude calculation means for calculating the system altitude by weighted averaging the measured altitudes of the sub-tracks selected by the sub-track selection means with the weighted value as a weight. An altitude calculation method using a three-dimensional radar.