CN1316722A - Method for topographic contour line conversion - Google Patents

Abstract

A topographic contour transform method for mobile communication includes such steps as determining the lattice point to be transformed, dividing the plane with the lattice point as its center into N regions, finding the neares point from the lattice point on the contour line in each region, obtaining its value, calcualting the distance from the nearsest point to the lattice point, and calculating the height of said lottice point.

Description

Method for topographic contour line conversion

The present invention relates to conversion method to the topographic contour of using on the geography.

Have the height that isocontour map is used to mark landform, utilize this map can represent the geographical height of present position intuitively, height for example above sea level or relative height etc.At moving communicating field, need utilize this level line to analyze as the foundation of setting up base station etc.

Usually the method that adopts is the digital height layer figure that earlier contour map is converted in the computing machine at present.And then utilize this digital height layer figure to analyze.In general, the data between the two adjacent height layers are stepped change, and are discrete.Isocontour vertical separation unit on the at present general map is bigger.And in fact, in mobile communication, be used for determining or judging that the Terrain Elevation value of signal attenuation degree institute foundation is less of number of base stations, in some cases, its accuracy requirement reaches below 1 meter.Therefore, be not meet application requirements in the mobile communication with regard to present digital height layer figure.

Therefore, the object of the present invention is to provide a kind of conversion method of topographic contour, it can utilize the bigger digital height layer figure of existing vertical separation unit, obtains vertical separation unit's digital height layer figure less, that meet the mobile communication application requirement.

Method for topographic contour line conversion provided by the invention comprises the following step:

(1) the definite grid point that will change;

(2) be the center with described grid point, the plane at grid point place all is separated into N zone, wherein, N is the natural number more than or equal to 4;

(3) seek from the nearest point of described grid point on the level line in each described zone, obtain the value of this point, and calculate the distance of described closest approach to described grid point;

(4) according to the value of each the described closest approach in each zone and from the distance of described grid point, calculate the height of described grid point, wherein, the height value of described closest approach is directly proportional with the distance of described grid point with it to the influence of the height value of described grid point.

By said method, can obtain more level and smooth equal pitch contour figure.

Describe the present invention in detail below in conjunction with accompanying drawing.

In the accompanying drawing:

Fig. 1 shows several width of cloth and has isocontour topomap;

Fig. 2 is used to explain method for topographic contour line conversion of the present invention;

Fig. 3 shows the flow process of method of the present invention.

Fig. 1 schematically shows the general topomap that has equal pitch contour.Level line of the curve representation of every sealing of Fig. 1, every level line is represented geographic height, and for example, the curve A among Fig. 1 is represented 100 meters of height, and curve B is represented 200 meters of height, and curve C is represented 300 meters of height, curve D is represented 400 meters of height.For general topomap, the interval unit of equal pitch contour is about about 100 meters.Such topomap generally can not satisfy the application requirements of analyzing number of base stations, base station distribution etc. in the mobile communication after converting digital height layer figure to.Therefore, need the littler topomap of contour interval unit.

Method of the present invention just is based on above-mentioned situation, utilizes the bigger equal pitch contour figure in existing interval, obtains less at interval equal pitch contour figure, to satisfy the requirement of mobile communication application.

The principle of method of the present invention institute foundation is: for any grid point in the topomap, its height value is the effect of altitude that is subjected to all directions, rule of thumb knowledge and actual landform knowledge, the height value of arbitrary grid point is subjected to the size of the influence on all directions and both distance dependents in the topomap.For example, on the hill-side a bit, its true altitude both had been subjected on the mountain top influence of a bit, also was subjected to influence more at the foot of the hill.When on the hill-side a bit from the mountain top when nearer, it is subjected to the influence of height value on mountain top just big, when on the hill-side a bit from the foot of the hill when nearer, it is subjected to the influence of height value at the foot of the hill just big.Therefore, based on this principle, the method of the height value of certain grid network point is in the calculating landform that the present invention proposes, utilize reference point height value nearest on these grid point all directions and this reference point to calculate apart from the distance of this grid point, that is, the height value of described reference point is directly proportional with the distance of described grid point with it to the influence of the height value of described grid point.

Explain method for topographic contour line conversion of the present invention below with reference to Fig. 2 and Fig. 3, its flowchart illustrations is at Fig. 4.

See also Fig. 2, Fig. 2 is that a width of cloth has isocontour topomap, and is relevant how with this topomap digitizing, so that the method that can allow computing machine handle all is known for the ordinary person in present technique field, therefore, here no longer describes in detail.

Among Fig. 2, curve X represents highly to be 100 meters level line, and curve Y represents highly to be another level line of 100 meters, and curve Z represents highly to be 200 meters level line.Level line in this topomap differential (being interval height) is 100 meters, therefore, does not meet the application requirements of mobile communication.Need carry out conversion process to it, to obtain the topomap differential than low height.Supposing the height (step S1) of O point (being also referred to as grid point) in the calculating chart, is the center with the O point, and topomap is divided into four zones: regional A, B, C and D (step S2).Then, in each zone, seek on the level line from the nearest point (step S3) of O point.The method of seeking point nearest on the level line has a lot, and for example, the distance of utilizing the O that has a few on COMPUTER CALCULATION all level lines in this zone to order is then by relatively obtaining nearest point; If precision prescribed is not high, also can mark several lines to this zone earlier from the O point, calculate the distance that all level line intersection points in these lines and this zone and O are ordered, then also by relatively obtaining nearest point.Adopt which kind of method to determine that closest approach can decide according to actual needs.

We observe the situation of seeking closest approach among the lower area A.

As shown in Figure 2, we adopt method of scoring to seek closest approach.Promptly in regional A, mark two straight line L1 and L2 again, the equal subregion A of straight line L1 and L2 from the O point.The intersection point of its cathetus L1 and level line X is L1A, L1B, with the intersection point of level line Z be L1C; The intersection point of straight line L2 and level line X is L2A, L2B, with the intersection point of level line Z be L2C.Can obtain by calculating, in these intersection points L1A, L1B, L1C, L2A, L2B and L2C, from O point nearest be L2A, therefore, getting L2A is that the height value that L2A is ordered is 100 meters from O point closest approach, its distance of ordering from O is D1.In each zone, carry out identical work then successively, obtain in each zone from the height value of the nearest point of O point and the distance of ordering from O.

After finishing above-mentioned work, can utilize the height value of closest approach in above-mentioned each zone and calculate the height value (step S4) that O is ordered from the distance that O is ordered.The principle of basis is: the height value of each closest approach is directly proportional with the distance of grid point with it to the influence of the height value of grid point.This proportional relation can embody by following formula: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{Ce}\·\mathrm{Ze}$ $\mathrm{Ce}=\frac{D_e}{\underset{o=1}{\overset{N}{\mathrm{\Σ}}}{D}_o}$ Formula (1)

Wherein, Z (i, j) be the height value of described grid point, i and j are the coordinate of this grid point, N is the number of regions of cutting apart, and Ce is the weighting coefficient of closest approach in e the zone, and Ze is the value of closest approach in e the zone, De is that closest approach is to the distance of described grid point in e the zone, and Do is the distance that closest approach arrives described grid point in o the zone.

In the formula (1), weighting coefficient Ce can also adopt following formula: $\mathrm{Ce}=\frac{{D_e}^2}{\underset{o=1}{\overset{N}{\mathrm{\Σ}}}{D_o}^2}$ Formula (2) $\mathrm{Ce}=\frac{{D_e}^y}{\underset{o=1}{\overset{N}{\mathrm{\Σ}}}{D_o}^y}$ Formula (3)

Wherein, y is a natural number $\mathrm{Ce}=\frac{\underset{o=1,o\≠e}{\overset{N}{\mathrm{\Π}}}{D_o}^y}{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}\underset{o=1,o\≠k}{\overset{N}{\mathrm{\Π}}}{D_o}^y}$ Formula (4)

Among the embodiment of Miao Shuing, topomap is divided into four zones in the above, in the practice, can precision as requested comes the quantity of regulation cut zone, generally speaking, the quantity of cut zone is at least 4, preferably 4 multiple.The region quantity of cutting apart is many more, and the precision that obtains is also high more.But correspondingly, operand is also big more.

In the above-described embodiments, in the step of seeking closest approach, in each zone, find out a closest approach, can certainly in each zone, find out a plurality of closest approaches, for example, among the regional A in Fig. 2, except the L1A point recently after, secondly near point is the L2A point, and this point also can be used as and calculates the reference point that O is ordered.When in each zone, finding out multiple spot, can adopt following formula to calculate the height value that O is ordered as reference point: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}(\underset{l=1}{\overset{M}{\mathrm{\Σ}}}{C}_{\mathrm{el}}\·Z_{\mathrm{el}})/M$ $C_{\mathrm{el}}=\frac{D_{\mathrm{el}}}{\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\underset{l=1}{\overset{M}{\mathrm{\Σ}}}{D}_{\mathrm{el}}}$ (formula 5)

Wherein, (i j) is the height value of described grid point to Z, and i and j are the coordinate of this grid point, and N is the number of regions of cutting apart, and M is the number of the reference point of getting in each zone; C _E1Be the weighting coefficient of the 1st reference point in e the zone, Z _E1Be the value of the 1st reference point in e the zone, D _E1Be in e the zone the 1st reference point to the distance of described grid point.

In the above-described embodiments, searching is carried out in whole regional extent from the nearest reference point of O point.In order to simplify computing, also can seek the point on the nearest level line of O point in the boundary line in zone, as reference point.The reference point of seeking also can be a plurality of.

After the height value that has calculated grid point, as shown in Figure 3, at step S5, determine whether have a few and all changed, if then EOC (step S6) if not, is then got back to step S1.

Described the conversion method of topographic contour of the present invention above in detail, those skilled in the art utilize various means can realize method of the present invention by top description.Method of the present invention can adopt software or hardware, and perhaps software and hardware mode realize.

Claims (8)

1, a kind of method for topographic contour line conversion comprises the following step:

(1) the definite grid point that will change;

(2) be the center with described grid point, the plane at grid point place all is separated into N zone, wherein, N is the natural number more than or equal to 4;

(3) seek from the nearest point of described grid point on the level line in each described zone, obtain the value of this point, and calculate the distance of described closest approach to described grid point;

(4) according to the value of each the described closest approach in each zone and from the distance of described grid point, calculate the height of described grid point, wherein, the height value of described closest approach is directly proportional with the distance of described grid point with it to the influence of the height value of described grid point.

2, the method for claim 1, it is characterized in that, in step (3), also seek on the level line in each described zone from the nearest a plurality of points of described grid point, obtain the value of these points, and calculate the distance of described a plurality of closest approach respectively to described grid point.

3, the method for claim 1 is characterized in that, in step (3), the point seeking on the boundary line in described zone on the nearest level line of described grid point obtains the value of this point, and calculates the distance of described closest approach to described grid point.

4, method as claimed in claim 3 is characterized in that, in step (3), a plurality of points seeking on the boundary line in described zone on the nearest level line of described grid point obtain the value of these points, and calculates the distance of described closest approach to described grid point.

As the described method of one of claim 1 to 4, it is characterized in that 5, the height value that calculates described grid point in step (4) adopts following formula: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{Ce}\·\mathrm{Ze}$ $\mathrm{Ce}=\frac{D_e}{\underset{o=1}{\overset{N}{\mathrm{\Σ}}}{D}_o}$

Wherein, Z (i, j) be the height value of described grid point, i and j are the coordinate of this grid point, N is the number of regions of cutting apart, and Ce is the weighting coefficient of closest approach in e the zone, and Ze is the value of closest approach in e the zone, De is that closest approach is to the distance of described grid point in e the zone, and Do is the distance that closest approach arrives described grid point in o the zone.

As the described method of one of claim 1 to 4, it is characterized in that 6, the height value that calculates described grid point in step (4) adopts following formula: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{Ce}\·\mathrm{Ze}$ $\mathrm{Ce}=\frac{{D_e}^2}{\underset{o=1}{\overset{N}{\mathrm{\Σ}}}{D_o}^2}$

Wherein, Z (i, j) be the height value of described grid point, i and j are the coordinate of this grid point, N is the number of regions of cutting apart, and Ce is the weighting coefficient of closest approach in e the zone, and Ze is the value of closest approach in e the zone, De is that closest approach is to the distance of described grid point in e the zone, and Do is the distance that closest approach arrives described grid point in o the zone.

As the described method of one of claim 1 to 4, it is characterized in that 7, the height value that calculates described grid point in step (4) adopts following formula: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\mathrm{Ce}\·\mathrm{Ze}$ $\mathrm{Ce}=\frac{\underset{o=1,o\≠e}{\overset{N}{\mathrm{\Π}}}{D_e}^y}{\underset{k=1}{\overset{N}{\mathrm{\Σ}}}\underset{o=1,o\≠k}{\overset{N}{\mathrm{\Π}}}{D_o}^y}$

Wherein, Z (i, j) be the height value of described grid point, i and j are the coordinate of this grid point, and N is the number of regions of cutting apart, and Ce is the weighting coefficient of closest approach in e the zone, Ze is the value of closest approach in e the zone, De is that closest approach is to the distance of described grid point in e the zone, and Do is that closest approach is to the distance of described grid point in o the zone, and y is a natural number.

As the described method of one of claim 1 to 4, it is characterized in that 8, the height value that calculates described grid point in step (4) adopts following formula: $Z(i,j)=\underset{e=1}{\overset{N}{\mathrm{\Σ}}}(\underset{l=1}{\overset{M}{\mathrm{\Σ}}}{C}_{\mathrm{el}}\·Z_{\mathrm{el}})/M$ $C_{\mathrm{el}}=\frac{D_{\mathrm{el}}}{\underset{e=1}{\overset{N}{\mathrm{\Σ}}}\underset{l=1}{\overset{M}{\mathrm{\Σ}}}{D}_{\mathrm{el}}}$

Wherein, (i j) is the height value of described grid point to Z, and i and j are the coordinate of this grid point, and N is the number of regions of cutting apart, and M is the number of the reference point of getting in each zone; C _E1Be the weighting coefficient of the 1st reference point in e the zone, Z _E1Be the value of the 1st reference point in e the zone, D _E1Be in e the zone the 1st reference point to the distance of described grid point.

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