CN104102771B - Automatic drawing method for land-sea ecotone meteorological isolines - Google Patents

Abstract

The invention discloses an automatic drawing method for land-sea ecotone meteorological isolines. The automatic drawing method includes steps of 1) reading data from multi-dimensional marine meteorological data, acquiring land-sea boundary data, and isolating marine regional data by overlay analysis; 2) setting a threshold value of judging a noisy point, judging each pixel, and if a pixel is the noisy point, correcting the pixel to acquire an effective numerical range of the marine region; 3) dividing the whole region according to the effective numerical range of the marine region; 4) respectively constructing interval tables of the marine region and other regions, and setting intervals with uneven densities on each region; 5) combining the intervals of the marine region and other regions; and 6) reading batch data through MATLAB (matrix laboratory ), and applying the intervals to MATLAB isolines drawing instructions to achieve the automatic drawing. By the automatic drawing method, the isolines effectively highlight changes of marine regional factors, show meteorological factors of a land region at the same time and can be applied to the fields, such as drawing a thematic map of the land-sea ecotone meteorology.

Description

A kind of sea land ecotone meteorological contour line automatic drafting method

Technical field

The present invention relates to the technical field of maritime meteorology isoplethes drawing.More particularly, to a kind of sea land ecotone is meteorological equivalent Line automatic drafting method.

Background technology

Isopleth is the smoothed curve that in map subject, the equal each point of numerical value is linked to be, and it is in the hydrology, geology, ocean, big The numerous areas such as gas have very important purposes, isobaric chart in such as field of pressure, the earth survey and draw in contour map, Ore body isogram in matter etc..The method comparative maturity of isoplethes drawing and filling at present, but in maritime meteorology neck Domain has problems.Maritime meteorology packet contains land and sea area, and element numerical value changes gently on ocean, and on land It is changed significantly.Isopleth can be made to concentrate on land area using traditional contour interval method to set up, then lack in sea area Few distinguishable isopleth, and its region that exactly maritime meteorology worker pays close attention to.Therefore, how to automatically configure ocean Meteorological contour line is spaced, thus improving the information content drawing key element, prominent interest region, is a problem demanding prompt solution.

For unequal-interval isopleth, there are two kinds of spaced methods at present：One is drafting personnel according to concrete data Arrange manually；Two is the interval setting based on area statistics.Manual setting method be using the complete isopleth of Software on Drawing after, according to effect Fruit constantly adjustment interval, until out satisfied result.This method often can obtain good effect, but draws Cumbersome, takes time and effort.The method of area statistics to some extent solves the problem of artificial drafting, it is possible to achieve business Change batch processing, but when being applied to this kind of special data of maritime meteorology, the isopleth effect drawn out cannot meet specialty will Ask.The isobaric interval of such as air typically requires and is set to special value, such as 2.5 hundred handkerchiefs or 400 handkerchiefs, and area statistics Method only divides according to homalographic principle it is impossible to solve this kind of specific demand.

For problem above, the present invention proposes a kind of sea land ecotone meteorological contour line automatic drafting method, first will be former Beginning key element does overlay analysis with extra large land boundary data, extracts sea area, then carries out spot denoising and be calculated ocean province Domain number range, selects suitable spacing value in conjunction with mapping table, merges ocean and land area and obtains unequal-interval interval, Afterwards interval is applied to the instruction of MATLAB isoplethes drawing to realize automatically drawing.Extra large land ecotone gas can be realized based on the method As the automatic drafting of isopleth, and sea area information can be projected.

Content of the invention

The purpose of the present invention is the problem for overcoming prior art to exist, and provides a kind of sea land ecotone meteorological contour line certainly Dynamic method for drafting.

A kind of sea land ecotone meteorological contour line automatic drafting method comprises the steps：

1) read out, from multilayer multivariable maritime meteorology raw data file, the layer data treating drawing isoline, then Obtain the extra large land boundary data consistent with this data form, using extra large land boundary data, overlay analysis are done to initial data, separate Go out ocean province numeric field data；

2) set and judge the threshold value of noise, each pixel in ergodic data, if currently the numerical value of pixel be around connected The variance of eight pixels deduct overall variance and be more than given threshold value then it is assumed that this pixel is noise, this pixel is carried out Correction, obtains sea area Effective Numerical scope with this；

3) division of Zone Full is obtained according to the Effective Numerical scope of sea area；

4) build the spacing sheet in sea area and other regions respectively, regional different density is arranged according to spacing sheet Interval；

5) merge the interval in sea area and other regions；

6) utilize MATLAB batch to read data, and by step 5) merge after interval be applied to MATLAB isoplethes drawing Instruction, realizes automatically drawing.

Described step 1) include：Read out from the multivariable maritime meteorology raw data file of multilayer and wait to draw One layer data of isopleth, this layer data is to be made up of the two-dimentional regular grid of n row m row, then obtains consistent with this data form N row m row extra large land boundary data, extra large land demarcates packet containing two-value data corresponding thereto, and each pixel quotes phase Same geographical position, in extra large land boundary two-value data, 0 represents other, and 1 represents ocean, using extra large land boundary data to initial data Do overlay analysis, isolate sea area data.

Described step 2) include：Set a threshold value judging noise, each pixel in ergodic data, if current picture Numerical value f (i, j) of unit and the variances sigma of eight pixels being around connected²Deduct overall varianceMore than given threshold value, then recognize It is noise for this pixel, the method can be represented with below equation：

In formula：g_lPut the numerical value of surrounding adjoint point for f (i, j)；

When confirming that certain pixel is noise, replace initial value with the result that below equation calculates,

In formula：F ' (i, j) is the new brightness of pixel；P is the probability that this pixel is noise,

Sea area data after above correction can obtain sea area Effective Numerical scope.

Described step 3) include：Obtain overall number range, then remove the result of calculation of sea area, it is obtained with this The number range in his region；Other subfield value scopes can be divided into two by sea area number range QO=[minO, maxO] Individual part, upper bound QL₁=(minL₁, maxL₁] and lower bound QL₂=[minL₂, maxL₂), they are scopes QA=of Zone Full One division of [minA, maxA]；

QA=QL₁∪QO∪QL₂(3)

QL in formula₁, QO and QL₂It is all empty for occuring simultaneously two-by-two；

If other numerical value are all greater than sea area, QL₁For empty set, if other numerical value are all less than sea area, QL₂For empty set.

Described step 4) include：For the number range of the sea area obtained and other regions, build spacing sheet and set Put the interval of regional different density, spacing sheet area field is divided into interest region and other regions, the interval of zones of different Setting principle is different, and interest region interval is less, and corresponding isopleth is also closeer, other interregional every relatively large, drafting Isopleth is also sparse；Because the different setting different interval of number range, described number range is paid close attention in same class region It is the interval belonging to range differences, the number range difference of sea area is maxO-minO.

Described step 5) include：By step 4) mapping of spacing sheet that builds, obtain following interval setting, ocean province Domain number range interval QIO=[minO, intervalO, maxO], other subfield value upper range limit QIL1=(minL₁, intervalL₁, maxL₁] and lower bound QIL2=[minL₂, intervalL₂, maxL₂), merge sea area and other regions Interval, obtains the interval QIA of overall region,

QIA=QIL₁∪QIO∪QIL₂(4)

QIL in formula₁, QIO and QIL₂It is all empty for occuring simultaneously two-by-two.

Described step 6) include：Read data using MATLAB batch, Calling MATLAB isoplethes drawing instructs Contour or contourf, the interval QIA after merging is applied to this instruction, realizes automatic batch and draws.

The present invention compared with prior art has an advantageous effect in that：The present invention pass through arrange unequal-interval interval it is ensured that There is a more dense isopleth sea area, can show the numerical value change of sea area so that in sea area originally by emphasis More sparse distribution of contours obtains more science, abundant；And in secondary important land area, the more intensive isopleth of script Relatively tend to sparse, to reduce the confusion degree of this region isopleth；It is whole that sea area and land area isopleth are embodied Body information is more complete, is provided that more meaningful reference value.

Brief description：

Fig. 1 is extra large land ecotone meteorological contour line automatic drafting method；

Fig. 2 is top air pressure numeric distribution；

Fig. 3 is ocean surface air pressure numeric distribution；

Fig. 4 is isoplethes drawing achievement.

Specific embodiment：

As shown in figure 1, extra large land ecotone meteorological contour line automatic drafting method comprises the steps：

1) read out, from multilayer multivariable maritime meteorology raw data file, the layer data treating drawing isoline, then Obtain the extra large land boundary data consistent with this data form, using extra large land boundary data, overlay analysis are done to initial data, separate Go out ocean province numeric field data；

2) set and judge the threshold value of noise, each pixel in ergodic data, if currently the numerical value of pixel be around connected The variance of eight pixels deduct overall variance and be more than given threshold value then it is assumed that this pixel is noise, this pixel is carried out Correction, obtains sea area Effective Numerical scope with this；

3) division of Zone Full is obtained according to the Effective Numerical scope of sea area；

4) build the spacing sheet in sea area and other regions respectively, regional different density is arranged according to spacing sheet Interval；

5) merge the interval in sea area and other regions；

6) utilize MATLAB batch to read data, and by step 5) merge after interval be applied to MATLAB isoplethes drawing Instruction, realizes automatically drawing.

Described step 1) include：Read out from the multivariable maritime meteorology raw data file of multilayer and wait to draw One layer data of isopleth, this layer data is to be made up of the two-dimentional regular grid of n row m row, then obtains consistent with this data form N row m row extra large land boundary data, extra large land demarcates packet containing two-value data corresponding thereto, and each pixel quotes phase Same geographical position, in extra large land boundary two-value data, 0 represents other, and 1 represents ocean, using extra large land boundary data to initial data Do overlay analysis, isolate sea area data.

Described step 2) include：Set a threshold value judging noise, each pixel in ergodic data, if current picture Numerical value f (i, j) of unit and the variances sigma of eight pixels being around connected²Deduct overall varianceMore than given threshold value, then recognize It is noise for this pixel, the method can be represented with below equation：

In formula：g_lPut the numerical value of surrounding adjoint point for f (i, j)；

When confirming that certain pixel is noise, replace initial value with the result that below equation calculates,

In formula：F ' (i, j) is the new brightness of pixel；P is the probability that this pixel is noise,

Sea area data after above correction can obtain sea area Effective Numerical scope.

Described step 3) include：Obtain overall number range, then remove the result of calculation of sea area, it is obtained with this The number range in his region；Other subfield value scopes can be divided into two by sea area number range QO=[minO, maxO] Individual part, upper bound QL₁=(minL₁, maxL₁] and lower bound QL₂=[minL₂, maxL₂), they are scopes QA=of Zone Full One division of [minA, maxA]；

QA=QL₁∪QO∪QL₂(3)

QL in formula₁, QO and QL₂It is all empty for occuring simultaneously two-by-two；

If other numerical value are all greater than sea area, QL₁For empty set, if other numerical value are all less than sea area, QL₂For empty set.

Described step 4) include：For the number range of the sea area obtained and other regions, build spacing sheet and set Put the interval of regional different density, spacing sheet area field is divided into interest region and other regions, the interval of zones of different Setting principle is different, and interest region interval is less, and corresponding isopleth is also closeer, other interregional every relatively large, drafting Isopleth is also sparse；Because the different setting different interval of number range, described number range is paid close attention in same class region It is the interval belonging to range differences, the number range difference of sea area is maxO-minO.

Described step 5) include：By step 4) mapping of spacing sheet that builds, obtain following interval setting, ocean province Domain number range interval QIO=[minO, intervalO, maxO], other subfield value upper range limit QIL1=(minL₁, intervalL₁, maxL₁] and lower bound QIL2=[minL₂, intervalL₂, maxL₂), merge sea area and other regions Interval, obtains the interval QIA of overall region,

QIA=QIL₁∪QIO∪QIL₂(4)

QIL in formula₁, QIO and QIL₂It is all empty for occuring simultaneously two-by-two.

Described step 6) include：Read data using MATLAB batch, Calling MATLAB isoplethes drawing instructs Contour or contourf, the interval QIA after merging is applied to this instruction, realizes automatic batch and draws.

Embodiment：

(1) using extra large land boundary data, overlay analysis are done to isopleth initial data, isolate the data of pelagic division

As a example when 23 days 12: 0 May in 2013, secondary Indian Ocean shows air pressure numerical forecasting product.Longitude range 30 ° of E～125 ° E, 20 ° of S～30 ° N of latitude scope, resolution ratio is 476*251.The overlay analysis of data of being demarcated by extra large land, point Separate out ocean and land partial data.Fig. 2 is the statistical chart of land area surface pressure numerical forecasting product data, to this data Analysis understand, the atmospheric pressure value scope of land area is 600-1100 hundred handkerchief, it is distributed toothing, interval even from 850-1020 Continuous have several peak values, progressively successively decreases to both sides.Fig. 3 is the statistical chart of sea area surface pressure numerical forecasting product data, sea The atmospheric pressure value in oceanic province domain concentrates on 1000-1020 interval, and rest interval only has a small amount of noise.

(2) adopt eight adjoint point methods to remove the noise of sea area data, obtain effective number range

Set and judge the threshold value of noise as 1, each pixel in ergodic data, if numerical value f (i, j) of current pixel and week Enclose the variances sigma of connected eight pixel²Deduct overall varianceMore than given threshold value then it is assumed that this pixel is noise.Warp Sea area data after correction can obtain sea area Effective Numerical scope.

(3) division of Zone Full is obtained according to the Effective Numerical scope of sea area

Being calculated overall number range is 600-1100 hundred handkerchief, and sea area scope is 1000-1020 hundred handkerchief, is obtained with this One to Zone Full is divided into [600,1000] ∪ (1000,1020) ∪ [1020,1100].

(4) spacing sheet of sea area and other regions, setting interval is built respectively using expertise

Specific according to the distribution of Indian Ocean surface pressure, devise mapping spacing sheet, as shown in table 2.

Table 1

(5) merge the interval in sea area and other regions

By the mapping of this spacing sheet, following interval setting can be obtained, sea area number range is spaced QIO= [1000,4,1020], land area number range upper bound QIL1=(1020,40,1100] and lower bound QIL2=[600,100, 1000), and merge after overall region interval QIA=[600,100,1000) ∪ [1000,4,1020] ∪ (1020,40, 1100].

(6) utilize MATLAB batch to read data, and by 5) merge after interval be applied to MATLAB isoplethes drawing and refer to Order, realizes automatically drawing

Calling MATLAB isoplethes drawing instructs contour, the interval QIA after merging is applied to this instruction, realizes certainly Dynamic batch is drawn.The result of isoplethes drawing is as shown in Figure 4.The automatic setting being spaced by unequal-interval, this figure is in ocean province There is more dense isopleth in domain, and it can show the air pressure change of sea area so that the information of isopleth is abundanter；And In secondary important land area, the method isopleth is relatively sparse, and the confusion degree to reduce isopleth is provided that more meaningful Reference value.

The present embodiment is using extra large land boundary data processing interest region, and combines between mapping table Auto-matching land and ocean Every value, effectively project the change of sea area key element, can be applicable to the fields such as the making of maritime meteorology thematic map.

Claims (7)

1. a kind of sea land ecotone meteorological contour line automatic drafting method is it is characterised in that comprise the steps：

1) read out, from multilayer multivariable maritime meteorology raw data file, the layer data treating drawing isoline, then obtain The extra large land boundary data consistent with this data form, does overlay analysis using extra large land boundary data, separates and go to sea to initial data Oceanic province numeric field data；

2) set the threshold value judging noise, each pixel in ergodic data, if the numerical value of current pixel and eight being around connected The variance of individual pixel deducts overall variance and is more than given threshold value then it is assumed that this pixel is noise, and this pixel is corrected, Sea area Effective Numerical scope is obtained with this；

3) division of Zone Full is obtained according to the Effective Numerical scope of sea area；

4) build the spacing sheet in sea area and other regions respectively, arranged between regional different density according to spacing sheet Every；

5) merge the interval in sea area and other regions；

6) utilize MATLAB batch to read data, and by step 5) merge after interval be applied to MATLAB isoplethes drawing and refer to Order, realizes automatically drawing.

2. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 1) include：Treat drawing isoline one layer is read out from the multivariable maritime meteorology raw data file of multilayer Data, this layer data is to be made up of the two-dimentional regular grid of n row m row, then obtains the sea of the n row m row consistent with this data form Land boundary data, extra large land demarcates packet containing two-value data corresponding thereto, and each pixel quotes identical geographical position, In extra large land boundary two-value data, 0 represents other, and 1 represents ocean, does overlay analysis using extra large land boundary data to initial data, point Separate out sea area data.

3. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 2) include：One threshold value judging noise of setting, each pixel in ergodic data, if the numerical value f of current pixel (i, J) variances sigma with eight pixels being around connected²Deduct overall varianceMore than given threshold value then it is assumed that this pixel is to make an uproar Point, the method can be represented with below equation：

$\frac{1}{8}{\mathrm{\Σ}}_{l=1}^8{\[g_l-f(i,j)\]}^2-\stackrel{\‾}{{\mathrm{\σ}}^2}>\mathrm{\ϵ}---\left(1\right)$

In formula：L is the numbering of eight adjoint point pixels around f (i, j) point, g_lPut the numerical value of surrounding adjoint point for f (i, j)；

When confirming that certain pixel is noise, replace initial value with the result that below equation calculates,

$f^{\′}(i,j)=(1-P)f(i,j)+P\[\frac{1}{8}{\mathrm{\Σ}}_{l=1}^8{g}_l\]---\left(2\right)$

In formula：F ' (i, j) is the new brightness of pixel；P is the probability that this pixel is noise,

Sea area data after above correction can obtain sea area Effective Numerical scope.

4. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 3) include：Obtain overall number range, then remove the result of calculation of sea area, the numerical value in other regions is obtained with this Scope；Other subfield value scopes can be divided into two parts, the upper bound by sea area number range QO=[minO, maxO] QL₁=(maxO, maxL₁] and lower bound QL₂=[minL₂, minO), they are scopes QA=[minA, maxA] of Zone Full One division；

QA=QL₁∪QO∪QL₂(3)

QL in formula₁, QO and QL₂It is all empty for occuring simultaneously two-by-two；

If other numerical value are all greater than sea area, QL₁For empty set, if other numerical value are all less than sea area, QL₂For Empty set.

5. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 4) include：For the number range of the sea area obtained and other regions, build spacing sheet setting regional not With the interval of density, spacing sheet area field is divided into interest region and other regions, and the interval setting principle of zones of different is different, Interest region interval is less, and corresponding isopleth is also closeer, other interregional every relatively large, the isopleth of drafting is also diluter Dredge；Because the different setting different interval of number range, described number range is concerned with belonging to range differences in same class region Interval, sea area number range difference be maxO-minO.

6. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 5) include：By step 4) mapping of spacing sheet that builds, obtain following interval setting, between the number range of sea area Every QIO=[minO, intervalO, maxO], other subfield value upper range limit QIL1=(minL₁,intervalL₁, maxL₁] and lower bound QIL2=[minL₂,intervalL₂,maxL₂), merge the interval in sea area and other regions, obtain whole The interval QIA of body region,

QIA=QIL₁∪QIO∪QIL₂(4)

QIL in formula₁, QIO and QIL₂It is all empty for occuring simultaneously two-by-two.

7. a kind of sea according to claim 1 land ecotone meteorological contour line automatic drafting method is it is characterised in that described Step 6) include：Using MATLAB batch read data, Calling MATLAB isoplethes drawing instruction contour or Contourf, the interval QIA after merging is applied to this instruction, realizes automatic batch and draws.