CN101303409A - Method for positioning radar PPI image pixel and implementing circuit thereof - Google Patents

Abstract

The invention discloses a positioning method of radar PPI image pixel and a realization circuit, wherein, the method comprises the steps: after receiving the echo data E(Thetaj, Ri) of a polar coordinate address Thetaj, Ri, the address Thetaj Ri is conversed as a rectangular coordinate; the compensation data of DeltaXji-1, the increment along the X direction, and DeltaYji-1, the increment along the Y direction, are obtained from a compensation database so as to generate the rectangular coordinate address Xji Yji corresponding to Thetaj, Ri; the echo data E (Thetaj, Ri) of the address Thetaj, Ri is stored in a mapped memory as PPI image pixel of address Xji Yji. The method of the invention through the way of nonlinear compensation causes the mapped memory in the range of radar PPI images to be wholly renewed and covered in one radar antenna scanning cycle so as to thoroughly solve the technical problem of discontinuousness or abruption of radar PPI images.

Description

The method of pixels of radar PPI images location and realization circuit

Technical field

The present invention relates to a kind of radar PPI images treatment technology, when especially relating to a kind of display device that utilizes the raster scanning system and realizing that radar PPI images shows, the method for its pixels of radar PPI images location and realize circuit.

Background technology

Show (PlanPosition Indicator with the display device of grating sweep volume system such as the planimetric position of realization radars such as CRT, LCD, PDP at present, when PPI) image shows, all want elder generation the azimuth-range coordinate of the echo data of radar transmitted pulse, be positioned in a series of storage unit of a mapped memory according to its place.

Be applicable to the mapped memory of raster scanning system, its storage unit is come addressing with the X-Y coordinate.A pixel on the corresponding display screen of each storage unit.Like this, the image of i range unit in the radar return data, the location in mapped memory, available following formula calculates:

X _i＝R _i·Cosθ _j；

Y _i＝R _i·Sinθ _j；

Wherein, i is the range unit sequence number, i=0,1,2 ... or i _Max, i _MaxBe generally 1023, promptly with the maximum operating range R of radar _MaxBe radius, will be apart from being divided into 1024 unit, so R _iRepresent the current detecting location and the distance of radar; J is an orientation quantifying unit number, j=0,1,2 ... or j _Max), j _MaxBe generally 4095, promptly when radar antenna with 360 ° of whens rotation, be divided into 4096 scan position unit with 360 °, so orientation θ _jOrientation angles when the expression radar antenna is surveyed current location.

Then should be 2048 * 2048 pixel cells with the mapped memory of the corresponding radar PPI images of resolution of polar coordinates image.Yet, when radar is worked, antenna from 0 °～360 ° processes that rotate a circle, θ _jFrom θ ₀Scan θ ₄₀₉₅, R _iAt each orientation angles θ _jThe position is from R ₀Scan R ₁₀₂₃Though, have 4096 * 1024 pixels still can not cover all unit in PPI mapped memory zone.

Theoretically, want at antenna from the cycle of 0 °～360 ° scanning one circles, all pixel cells of PPI video memory all are updated once at least, then need the azimuth discrimination unit is increased at least: $2\mathrm{\πR}\·\sqrt{2}=2\×3.14\×1024\×1.44=9093$

In the formula Registration bias coefficient when converting rectangular coordinate to for polar coordinates, R _MaxBe the range unit number, general value is 1024.

As seen, even the workload that radar PPI images is generated doubles azimuth discrimination unit number θ _MaxReach 8192, also be difficult to thoroughly address the above problem.

Therefore, how to solve in the radar PPI images generative process because of mapped memory can not be covered comprehensively and cause radar PPI images to occur discontinuous or the division phenomenon, become one of technical barrier that current urgent need solves.

Summary of the invention

The objective of the invention is to propose the method for a kind of pixels of radar PPI images location and realize circuit, make the mapped memory in the radar PPI images scope all be updated covering by the nonlinear compensation mode, technical matters discontinuous or the division phenomenon occurs with thorough solution radar PPI images a radar antenna scan period.

For addressing the above problem, the present invention discloses the method for a kind of pixels of radar PPI images location, comprising:

In receiving polar coordinates address θ _jR _iEcho data E (θ _j, R _i) after, with address θ _jR _iDo the rectangular coordinate conversion and from compensation database, obtain directions X increment Delta X _Ji-1With Y direction increment Delta Y _Ji-1Offset data, calculated address θ _jR _iCorresponding rectangular coordinate address X _JiY _Ji

With address θ _jR _iEcho data E (θ _j, R _i) as address X _JiY _JiThe PPI image pixel deposit in the mapped memory.

More excellent, described compensation database adopts following method to obtain:

Improve the azimuthal resolution of PPI image update;

Calculate each pixel on adjacent two sweep traces, find out the pixel that is not scanned between adjacent two sweep traces;

Adjust the directions X increment Delta X of the pixel pixel on every side that is not scanned and the offset data of Y direction increment Delta Y, the local sweep trace path that changes makes wherein inswept pixel that this is not scanned of two sweep traces under the condition that does not increase every total pixel of sweep trace;

Each pixel on each bar sweep trace of order computation, and adjust and fill the pixel that wherein is not scanned, described compensation database produced.

More excellent, described rectangular coordinate address X _JiY _JiBe by when the radar antenna orientation angles be θ _jFrom R ₀When beginning to scan, place X to X, Y scan counter respectively _J0And Y _J0, and add up the respectively offset data of corresponding directions X increment Delta X and Y direction increment Delta Y of pixel X of every renewal, Y scan counter obtains.

In addition, the present invention also discloses the realization circuit of a kind of pixels of radar PPI images location, comprising:

Coordinate transformation circuit and compensation database are used for receiving polar coordinates address θ _jR _iEcho data E (θ _j, R _i) after, with address θ _jR _iDo the rectangular coordinate conversion and from compensation database, obtain directions X increment Delta X _Ji-1With Y direction increment Delta Y _Ji-1Offset data;

Address XY produces circuit, is used for calculated address θ _jR _iCorresponding rectangular coordinate address X _JiY _Ji

Mapped memory is used for address θ _jR _iEcho data E (θ _j, R _i) deposit address X in _JiY _JiStorage unit.

More excellent, described address XY produces circuit and comprises:

X scan counter and Y scan counter, be respectively applied for when the radar antenna orientation angles be θ _jFrom R ₀When beginning to scan, place initialization data X _J0And Y _J0, and the offset data of when pixel of every renewal, add up respectively corresponding directions X increment Delta X and Y direction increment Delta Y, the address X of directions X under the acquisition rectangular coordinate _JiAddress Y with the Y direction _Ji

More excellent, the realization circuit of pixels of radar PPI images of the present invention location also comprises:

Scanning broadening decision circuitry is used to judge whether radar launches a new direct impulse, thereby has begun a new range sweep;

Orientation broadening treatment circuit is used for not enough j in interior 360 ° of radar antenna one week _MaxThe detection scanning data be extended to and j _MaxThe PPI image that number equates upgrades scan-data.

Compared with prior art, the present invention has following beneficial effect:

The present invention has been owing to taked the compensation of suitable algorithm and data necessary to the XY address, when radar antenna at polar coordinates address θ _jR _iWith θ _jR _I+1Any twice continuous distance by radar scanning, there is not accessed storage unit in the mapped memory, thereby eliminated the elementary area that is not covered in the PPI mapped memory, thoroughly solved lonely line splitting of radar PPI images generation echo and discontinuous technical matters by echo scanning.

Description of drawings

Fig. 1 is the synoptic diagram that the present invention realizes principle;

Fig. 2 is the synoptic diagram of a preferred embodiment of the present invention;

Fig. 3 A and Fig. 3 B are respectively through the PPI image scanning pixel synoptic diagram before and after the address date compensation.

Embodiment

As shown in Figure 1.Pixels of radar PPI images positioning circuit of the present invention comprises: the coordinate transformation circuit and the compensation database that polar coordinates address θ R are converted to rectangular coordinate address XY; And the address XY that generates the mapped memory memory address XY be used to store the pixels of radar PPI images data produces circuit.

When radar is received polar coordinates address θ _jR _iEcho data E (θ _j, R _i) after, with θ _jR _iAs the address, from coordinate transformation circuit and compensation database, read corresponding directions X increment Delta X _Ji-1With Y direction increment Delta Y _Ji-1Offset data, be sent to address XY and produce circuit, calculated address θ _jR _iCorresponding rectangular coordinate address X _JiY _JiWith address θ _jR _iEcho data E (θ _j, R _i) as address X _JiY _JiThe PPI image pixel deposit in the mapped memory.

As previously mentioned, the scanner uni of radar pulse is by following coordinate in sequence to the renewal of PPI mapped memory:

θ _jR _o，θ _jR ₁，θ _jR ₂，...，θ _jR _max；

θ _j+1R _o，θ _j+1R ₁，θ _j+1R ₂，...，θ _j+1R _max；

θ _j+2R _o，θ _j+2R ₁，...，θ _j+2R _max；

θ _maxR _o，θ _maxR ₁，...，θ _maxR _max。

That is to say that radar antenna is with orientation angles θ _jBeginning is respectively from scanning distance R _oTo R _MaxAfter finishing a range sweep, from continuous next orientation angles θ _J+iDoing range sweep, is 360 ° one antenna scanning cycle until finishing, and begins the next antenna scanning cycle again.

Therefore, polar coordinates address θ _jR _iCorresponding rectangular coordinate address X _JiY _JiCan be represented by the formula:

X _Ji=X _Ji-1± Δ X _Ji-1,+or-depend on the residing octant of coordinate points;

Y _Ji=Y _Ji-1± Δ Y _Ji-1,+or-depend on the residing octant of coordinate points.

ΔX _ji-1＝INT(R _i·sinθ _j)+X _jo-X _ji-1；

ΔY _ji-1＝INT(R _i·Cosθ _j)+Y _jo-Y _ji-1。

Perhaps be expressed as:

X _Ji+1=X _Ji± Δ X _Ji,+or-depend on the residing octant of coordinate points;

Y _Ji+1=Y _Ji± Δ Y _Ji,+or-depend on the residing octant of coordinate points;

ΔX _ji＝INT(R _i+1·sinθ _j)+X _jo-X _ji；

ΔY _ji＝INT(R _i+1·Cosθ _j)+Y _jo-Y _ji。

In the formula: X _JiBe polar coordinates point θ _jR _iCorresponding X coordinate; Y _JiBe polar coordinates point θ _jR _iCorresponding Y coordinate; Δ X _JiBe polar coordinates point θ _jR _iTo θ _jR _I+1Between the directions X increment, value is 0 or 1; Δ Y _JiBe polar coordinates point θ _jR _iTo θ _jR _I+1Between Y direction increment, value is 0 or 1; X _Jo, Y _JoBe respectively radar antenna at orientation angles θ _jRange sweep starting point polar coordinates address θ _jR ₀Corresponding rectangular coordinate address.

Obviously, as long as memory and maintenance X _Ji, Y _Ji, add Δ X _JiWith Δ Y _Ji, just can calculate X apace _Ji+1And Y _Ji+1Coordinate.

In the present embodiment, X _Ji, Y _JiRealize by the parts of two X, Y scan counter respectively.Radar antenna is at orientation angles θ _jRange sweep when beginning, insert these range sweep starting point polar coordinates address θ respectively at X, Y scan counter _jR ₀Corresponding rectangular coordinate address X _JoAnd Y _JoPixel of later every renewal, X, Y scan counter respectively add corresponding Δ X _JiWith Δ Y _JiAnd keep, its output is exactly polar theta _jR _I+1Rectangular coordinate address X _Ji+1Y _Ji+1Wherein, Δ X _JiWith Δ Y _JiThen provide by compensation database.

Because compensation database off line in advance produces, thereby above-mentioned scheme will be asked Sin θ in the image update process _jWith Cos θ _jAnd and R _iThe computational short cut that multiplies each other is for reading Δ X _JiWith Δ Y _JiAnd add up in X, Y scan counter, computing velocity when having improved the PPI image update has greatly reduced difficulty simultaneously.

As shown in Figure 2, be a preferred embodiment of the present invention.It is limited and have truncated error or weighing error that this embodiment further solves the present invention's employed binary digit in calculating the process of offset data, causes in PPI image generative process, and mapped memory exists individual memory cell may not can to upgrade.

Compared to Figure 1, the pixels of radar PPI images positioning circuit of present embodiment further comprises: scanning broadening decision circuitry and orientation broadening treatment circuit.

The azimuthal resolution of image update is improved, such as bringing up to 8192; And be 8192 with the radar scan-line data that the emission detection pulse scans in 360 ° also broadening, image update coordinate coupling.

Order computation goes out each pixel in 1024 sweep traces of radar antenna scan position angle in 0～45 ° of scope in advance in this embodiment, and adjust and fill the pixel that wherein is not scanned, form the compensation database of antenna scanning orientation angles correspondence in 0～45 ° of scope; In other 7 octants during image update, only need according to an orientation sign indicating number high position to scan counter add/exchange Δ X, the Δ Y of down control or cooperation get final product, and be as shown in table 1.

Octant	Between azimuthal bin	θ j	X ji+1	Y ji+1
					0	0°≤θ j∠45°	θ j	X ji+ΔX ji+1	Y ji-ΔY ji+1
1	45°≤θ j∠90°	90°-θ j	X ji+ΔY ji+1	Y ji-ΔX ji+1
					2	90°≤θ j∠135°	θ j-90°	X ji+ΔY ji+1	Y ji+ΔX ji+1
3	135°≤θ j∠180°	180°-θ j	X ji+ΔX ji+1	Y ji+ΔY ji+1
					4	180°≤θ j∠225°	θ j-180°	X ji-ΔX ji+1	Y ji+ΔY ji+1
5	225°≤θ j∠270°	270°-θ j	X ji-ΔY ji+1	Y ji+ΔX ji+1
					6	270°≤θ j∠315°	θ j-270°	X ji-ΔY ji+1	Y ji-ΔX ji+1
7	315°≤θ j∠360°	360°-θ j	S ji-ΔX ji+1	Y ji-ΔX ji+1

XY coordinate transformation table in each octant of table 1

Therefore, as radar antenna orientation angles θ _jThe time, only need be according to orientation angles θ _jResiding octant according to the XY coordinate transformation of this octant correspondence, can obtain corresponding rectangular coordinate address fast.

Shown in Fig. 3 A and Fig. 3 B, be respectively through the PPI image scanning pixel synoptic diagram before and after the address date compensation.The dotted line joining is represented the storage unit of a storage PPI image pixel in the mapped memory.Therefore, before the XY address not being done the data compensation, have the pixel that is not scanned between two sweep traces, or there is the storage unit that is not updated in each radar antenna in the cycle; And adopt the present invention that the XY address is done no longer to have the pixel that is not scanned between any two continuous sweep traces after the data compensation, or each radar antenna is in the cycle, and storage unit all in the mapped memory all are updated.

To sum up, the present invention has been owing to taked the compensation of suitable algorithm and data necessary to the XY address, when radar antenna at polar coordinates address θ _jR _iWith θ _jR _I+1Any twice continuous distance by radar scanning, there is not accessed storage unit in the mapped memory, thereby eliminated the elementary area that is not covered in the PPI mapped memory, thoroughly solved lonely line splitting of radar PPI images generation echo and discontinuous technical matters by echo scanning.

Claims (6)

1, the method for a kind of pixels of radar PPI images location is characterized in that, comprising:

In receiving polar coordinates address θ _jR _iEcho data E (θ _j, R _i) after, with address θ _jR _iDo the rectangular coordinate conversion and from compensation database, obtain directions X increment Delta X _Ji-1With Y direction increment Delta Y _Ji-1Offset data, calculated address θ _jR _iCorresponding rectangular coordinate address X _JiY _Ji

With address θ _jR _iEcho data E (θ _j, R _i) as address X _JiY _JiThe PPI image pixel deposit in the mapped memory.

2, the method for pixels of radar PPI images according to claim 1 location is characterized in that described compensation database adopts following method to obtain:

Improve the azimuthal resolution of PPI image update;

Calculate each pixel on adjacent two sweep traces, find out the pixel that is not scanned between adjacent two sweep traces;

Adjust the directions X increment Delta X of the pixel pixel on every side that is not scanned and the offset data of Y direction increment Delta Y, the local sweep trace path that changes makes wherein inswept pixel that this is not scanned of two sweep traces under the condition that does not increase every total pixel of sweep trace;

Each pixel on each bar sweep trace of order computation, and adjust and fill the pixel that wherein is not scanned, described compensation database produced.

3, the method for pixels of radar PPI images according to claim 1 location is characterized in that described rectangular coordinate address X _JiY _JiBe by when the radar antenna orientation angles be θ _jFrom R ₀When beginning to scan, place X to X, Y scan counter respectively _J0And Y _J0, and add up the respectively offset data of corresponding directions X increment Delta X and Y direction increment Delta Y of pixel X of every renewal, Y scan counter obtains.

4, the realization circuit of a kind of pixels of radar PPI images location is characterized in that, comprising:

Compensation database;

Coordinate transformation circuit is used for receiving polar coordinates address θ _jR _iEcho data E (θ _j, R _i) after, with address θ _jR _iDo the rectangular coordinate conversion and from compensation database, obtain directions X increment Delta X _Ji-1With Y direction increment Delta Y _Ji-1Offset data;

Address XY produces circuit, is used for calculated address θ _jR _iCorresponding rectangular coordinate address X _JiY _Ji

Mapped memory is used for address θ _jR _iEcho data E (θ _j, R _i) deposit address X in _JiY _JiStorage unit.

5, the realization circuit of pixels of radar PPI images according to claim 4 location is characterized in that, described address XY produces circuit and comprises:

X scan counter and Y scan counter, be respectively applied for when the radar antenna orientation angles be θ _jFrom R ₀When beginning to scan, place initialization data X _J0And Y _J0, and the offset data of when pixel of every renewal, add up respectively corresponding directions X increment Delta X and Y direction increment Delta Y, the address X of directions X under the acquisition rectangular coordinate _JiAddress Y with the Y direction _Ji

6, the realization circuit of pixels of radar PPI images according to claim 4 location is characterized in that, also comprises:

Scanning broadening decision circuitry is used to judge whether radar launches a new direct impulse, thereby has begun a new range sweep;

Orientation broadening treatment circuit is used for not enough j in interior 360 ° of radar antenna one week _MaxThe detection scanning data be extended to and j _MaxThe PPI image that number equates upgrades scan-data.

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