CN104089607A - Normal case photography forest metrology method through common digital camera - Google Patents

Abstract

The invention discloses a normal case photography forest metrology method through a common digital camera. The method comprises the following steps: setting a sighting rod as a measurement reference object at a place which is farthest away from a shooting point on the sample plot edge under random topographic condition, and measuring two parameters, namely the diameter at breast height and the tree height of each sample tree in the sample plot by utilizing fixed focus horizontal normal case photography. According to the method, the defects that the data acquisition period is long, the efficiency is low and the precision is low in the traditional method for measuring the diameter at breast height and tree height of sample trees are overcome, the efficiency and precision are improved, and the period is shortened.

Description

A kind of ordinary digital camera normal case photography method for measuring forest

One, technical field

The present invention relates to a kind of ordinary digital camera normal case photography method for measuring forest, particularly under any topographic condition, utilize to focus level and photograph, line rod is being set realizes under auxiliary the measurement of the sample trees diameter of a cross-section of a tree trunk 1.3 meters above the ground, the height of tree in sample ground.

Two, technical background

The diameter of a cross-section of a tree trunk 1.3 meters above the ground and the height of tree are two important factors of enumeration in measuring forest, tree breast diameter survey adopts diameter of a cross-section of a tree trunk 1.3 meters above the ground chi hand dipping at present, belong to contact type measurement, impact due to landform, understory shrub, the diameter of a cross-section of a tree trunk 1.3 meters above the ground that measures every strain sample trees in sample ground wastes time and energy, need a people to measure, people's record, human cost is higher.The height of tree is measured and is adopted altimeter to measure, and exists treetop summit to be difficult to the problems such as accurately judgement, causes measuring error larger, and needs two people to coordinate, and measures efficiency lower.

Therefore, in forest inventory investigation process, adopt traditional instrument to measure standing forest and inevitably brought a lot of troubles and error.The present invention is under any topographic condition, utilization focuses level and photographs, line rod be set realizing under auxiliary the measurement of the sample trees diameter of a cross-section of a tree trunk 1.3 meters above the ground, the height of tree in sample ground, measurement speed is fast, only need a people to complete, after obtaining sample ground photo, can carry out interior industry interpretation, process and can obtain the sample ground sample trees diameter of a cross-section of a tree trunk 1.3 meters above the ground and the height of tree, and measured value can persistence.General Promotion the speed of data processing, intelligent degree.

Three, summary of the invention

In order to overcome classic method, measure the sample trees diameter of a cross-section of a tree trunk 1.3 meters above the ground, the height of tree exists data acquisition cycle long, efficiency is low, the shortcoming of low precision is raised the efficiency and precision, in the shortening cycle, the object of this invention is to provide a kind of ordinary digital camera normal case photography method for measuring forest.

The object of the present invention is achieved like this:

1. under any topographic condition, first in sample destination edge from shooting point diagonal farthest, 1 line rod is set as measuring reference object; Secondly guaranteeing under horizontal normal case photography condition, taking the digital photo in sample ground.

2. the digital photo analytic method in sample ground is as follows: first, it is (U that the image space coordinate of line rod bottom on the digital photo in sample ground is set ₀, V ₀), in focal distance f, under the line rod condition that highly h is known, utilize digital-to-analogue 1. $\left\{\begin{array}{c}{X}_0=\frac{h}{V_0}{U}_0\\ Y_0=\frac{h}{V_0}f\\ Z_0=h\end{array}\right.$ Calculate line rod bottom object coordinates (X ₀, Y ₀, Z ₀); Next, the image space coordinate that arbitrfary point is set on the digital photo in sample ground is (U _i, V _i), according to digital-to-analogue 2. $\left\{\begin{array}{c}{X}_i=X_0\frac{U_i}{U_0}=\frac{h}{V_0}{U}_i\\ Y_i=Y_0\frac{V_i}{V_0}=\frac{h}{V_0}\frac{U_i}{U_0}f\\ Z_i=\sqrt{{X_i}^2+{Y_i}^2}\frac{V_i}{\sqrt{f^2+U_i^2}}\end{array}\right.$ Calculate arbitrfary point object coordinates (X _i, Y _i, Z _i).

3. in sample ground, the diameter of a cross-section of a tree trunk 1.3 meters above the ground calculation method of every strain sample trees is as follows: according to the digital photo analytic method in sample ground described in step 2, calculate the object space X coordinate figure (X at point of contact, left and right, 1.3 meters of of every strain sample trees in sample ground _{i, 1.3 left sides}, X _{i, 1.3 right sides}) according to digital-to-analogue D _i=X _{i, 1.3 left sides}-X _{i, 1.3 right sides}resolve diameter of a cross-section of a tree trunk 1.3 meters above the ground D.

4. in sample ground, the height of tree calculation method of every strain sample trees is as follows: according to digital-to-analogue obtain the treetop summit Z of every strain sample trees in sample ground _ip, utilize digital-to-analogue H _i=Z _ip-Z _i0calculate the height of tree.

This invention has the following advantages compared with the conventional method:

1. utilize and focus horizontal normal case photography metering system, take the digital photo of sample trees in sample ground, can measure the sample trees diameter of a cross-section of a tree trunk 1.3 meters above the ground and height of tree value, greatly alleviate and measure operation intensity.

2. for current forest survey measuring equipment, fall behind, the problems such as inefficiency, utilize photogrammetric mode, realize portable, easy-to-use, the efficient measurement pattern of forest inventory investigation.

Four, accompanying drawing explanation

Fig. 1 is measuring principle figure of the present invention.

Five, embodiment:

(1) under any topographic condition, first select the sample ground of one 20 * 30, in sample destination edge, from shooting point diagonal farthest, 1 red white equidistant alternate line rod is set as measuring reference object;

(2) guaranteeing under horizontal normal case photography condition, using ordinary digital camera to take a digital photo in sample ground;

(3) using in Photoshop software pixel coordinate survey instrument to obtain the image space coordinate of line rod bottom on the digital photo in sample ground is (U ₀, V ₀), in focal distance f, under the line rod condition that highly h is known, utilize digital-to-analogue $\left\{\begin{array}{c}{X}_0=\frac{h}{V_0}{U}_0\\ Y_0=\frac{h}{V_0}f\\ Z_0=h\end{array}\right.$ Calculate line rod bottom object coordinates (X ₀y ₀, Z ₀);

(4) on the digital photo in sample ground, use Photoshop software in the pixel coordinate survey instrument image space coordinate that obtains arbitrfary point be (U _i, V _i), according to digital-to-analogue $\left\{\begin{array}{c}{X}_i=X_0\frac{U_i}{U_0}=\frac{h}{V_0}{U}_i\\ Y_i=Y_0\frac{V_i}{V_0}=\frac{h}{V_0}\frac{U_i}{U_0}f\\ Z_i=\sqrt{{X_i}^2+{Y_i}^2}\frac{V_i}{\sqrt{f^2+U_i^2}}\end{array}\right.$ Calculate arbitrfary point object coordinates (X _i, Y _i, Z _i);

(5), according to the digital photo analytic method in above-mentioned sample ground, calculate the object space X coordinate figure (X at point of contact, left and right, 1.3 meters of of every strain sample trees in sample ground _{i, 1.3 left sides}, X _{i, 1.3 right sides}) according to digital-to-analogue D _i=X _{i, 1.3 left sides}-X _{i, 1.3 right sides}resolve diameter of a cross-section of a tree trunk 1.3 meters above the ground D;

(6) utilize digital-to-analogue obtain the treetop summit Z of every strain sample trees in sample ground _ipwith standing tree leading thread central point Z _i0, recycling digital-to-analogue H _i=Z _ip-Z _i0calculate the height of tree.

Claims (4)

1. an ordinary digital camera normal case photography method for measuring forest, is characterized in that: under topographic condition arbitrarily, first in sample destination edge from shooting point diagonal farthest, 1 line rod is set as measuring reference object; Secondly guaranteeing under horizontal normal case photography condition, taking the digital photo in sample ground; Finally by the digital photo in sample ground is resolved to the diameter of a cross-section of a tree trunk 1.3 meters above the ground and the height of tree of obtaining every strain sample trees in sample ground.

2. according to claim 1 ordinary digital camera normal case photography method for measuring forest, it is characterized in that: wherein, the digital photo analytic method in sample ground is as follows: first, it is (U that the image space coordinate of line rod bottom on the digital photo in sample ground is set ₀, V ₀), in focal distance f, under the line rod condition that highly h is known, utilize digital-to-analogue 1. $\left\{\begin{array}{c}{X}_0=\frac{h}{V_0}{U}_0\\ Y_0=\frac{h}{V_0}f\\ Z_0=h\end{array}\right.$ Calculate line rod bottom object coordinates (X ₀, Y ₀, Z ₀); Next, the image space coordinate that arbitrfary point is set on the digital photo in sample ground is (U _i, V _i), according to digital-to-analogue 2. $\left\{\begin{array}{c}{X}_i=X_0\frac{U_i}{U_0}=\frac{h}{V_0}{U}_i\\ Y_i=Y_0\frac{V_i}{V_0}=\frac{h}{V_0}\frac{U_i}{U_0}f\\ Z_i=\sqrt{{X_i}^2+{Y_i}^2}\frac{V_i}{\sqrt{f^2+U_i^2}}\end{array}\right.$ Calculate arbitrfary point object coordinates (X _i, Y _i, Z _i).

3. according to claim 1 ordinary digital camera normal case photography method for measuring forest, it is characterized in that: wherein, in sample ground, the diameter of a cross-section of a tree trunk 1.3 meters above the ground calculation method of every strain sample trees is as follows: the digital photo analytic method in sample according to claim 2 ground, calculates the object space X coordinate figure (X at point of contact, left and right, 1.3 meters of of every strain sample trees in sample ground _{i, 1.3 left sides}, X _{i, 1.3 right sides}) according to digital-to-analogue D _i=X _{i, 1.3 left sides}-X _{i, 1.3 right sides}resolve diameter of a cross-section of a tree trunk 1.3 meters above the ground D.

4. according to claim 1 ordinary digital camera normal case photography method for measuring forest, it is characterized in that: wherein, in sample ground, the height of tree calculation method of every strain sample trees is as follows: according to digital-to-analogue obtain the treetop summit Z of every strain sample trees in sample ground _ip, utilize digital-to-analogue H _i=Z _ip-Z _i0calculate the height of tree.