CN104567691A - Method for directly determining stand volume with mobile phone - Google Patents

Abstract

The invention discloses a method for directly determining the stand volume with a mobile phone, wherein the method comprises the following steps: determining the number and volume of trees in a forest stand per unit area by an angle gauge method; taking an ordinary mobile phone as a tool, setting angle gauge factors in mobile phone tree-measurement software; when certain angle gauge factor Fg is used, measuring around 360 degrees from sampling points, and observing heights of trunks above the ground, wherein the trunks are at places where the angle gauge notch is just tangent to the trunks above the breast height; the method for calculating the stand volume is as follows: the volume per hectare (M) is equal to the sum (in m) of heights of the trunks at all tangent places of each observed tree on the forest land above the ground multiplied by the angle gauge factor (referring to the Specification for the formula).

Description

A kind of mobile phone directly measures stand volume method

One, technical field

The present invention relates to the measuring method of stand volume in a kind of forest inventory investigation, particularly a kind of mobile phone directly measures the method for stand volume.

Two, technical background

In traditional forest resource monitoring, the measurement of stand volume is an insoluble problem always, usually adopts measurement method and ocular estimate to measure the volume of timber of standing forest.Measurement method can be divided into again full woods to survey and local actual measurement, and it determines that the method for stand volume can be divided into again mean sample tree method and number table method etc.But traditional technology has obvious shortcoming and defect:

1. in real work, full woods measurement method is time-consuming takes a lot of work, and only just adopts when special requirements such as the little cutting area of standing forest area and scientific experiments.

2. ocular estimate makes supplementary means estimation stand volume by assize instrument and assize number table, there is larger uncertainty.

So in National Forest resource examination process continuously, when adopting traditional measurement method and ocular estimate to measure stand volume, inevitably bring a lot of trouble and precision is not high, inefficiency.How stand volume is investigated in raising, reduces costs, raises the efficiency and become this area scientific and technical personnel problem anxious to be resolved.

Three, summary of the invention

Check in National Forest resource a lot of troubles that process inevitably brings continuously to overcome existing measurement stand volume method, improve accuracy of observation and work efficiency, the object of this invention is to provide a kind of method that mobile phone directly measures stand volume, it is when accuracy of observation improves, significantly reduce the workload of field operation, improve efficiency, overcome the shortcoming that prior art exists.

It is instrument that the present invention is achieved in that with regular handset, installs the software with assize function in mobile phone, and the subtended angle θ arranging this assize software is 1 ° 08 ' 45 ".Point centered by the position at mobile phone place, aims at the diameter of a cross-section of a tree trunk 1.3 meters above the ground of tree by this subtended angle, if the diameter of a cross-section of a tree trunk 1.3 meters above the ground of tree is cut mutually with subtended angle or tangent, be then designated as 1 strain.From this central point around survey 360 °, if when the number of cutting the tree of (or tangent) is mutually Z strain, can prove that per hectare basal area G is:

G＝Z(m ²/hm ²) (1)

Meanwhile, just the trunk at the tangent place of above trunk, apart from the height on ground, represents with h record subtended angle with the diameter of a cross-section of a tree trunk 1.3 meters above the ground.The method calculating stand volume is as follows: the per hectare volume of timber (M) equals all trunks of each strain observation wood on forest land apart from floor level sum (in units of m), that is:

$M=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{h}_i---\left(2\right)$

Wherein the proof of formula (1) is as follows:

When using the diameter of a cross-section of a tree trunk 1.3 meters above the ground of mobile phone for measuring tree, suppose that trunk diameter is d, the area of section of trunk is a, and the radius on sample ground is R, and the area on sample ground is A, and the subtended angle of mobile phone is θ, and θ=1 ° 08 ' 45 ".As shown in Figure 1, AB is the diameter d of trunk, and of is the radius R on sample ground.

Can obtain according to sine,

$\sin \frac{\mathrm{\θ}}{2}=\frac{\mathrm{fg}}{\mathrm{of}}=\frac{0.5\mathrm{AB}}{\mathrm{of}}=\frac{0.5d}{R}$

$\frac{d}{R}=2\sin \frac{\mathrm{\θ}}{2}\≈\frac{1}{50}$

Therefore, the area of section of trunk and the area ratio on sample ground are:

$\frac{a}{A}=\frac{\frac{\mathrm{\π}}{4}{d}^2}{\mathrm{\π}{R}^2}=\frac{1}{4}{\left(\frac{1}{50}\right)}^2=\frac{1}{10000}$

Illustrate that the enlarged areas when sample ground is 10000m ²time, in sample ground, to be that the trunk area of section of d is then corresponding expand as 1m to each strain diameter ².Therefore, when there being Z strain tree to cut (or tangent) mutually with the subtended angle of assize software in sample ground, then G=Z.

The proof of formula (2) is as follows: according to formula (1), and when the height at subtended angle and the tangent place of the above trunk of the diameter of a cross-section of a tree trunk 1.3 meters above the ground is h, 1hm is expanded as in the transversal section at the arbitrary position of the following trunk of this height ²time, its per hectare basal area is all 1m ².Therefore, it is highly hm that the volume of below h trunk can be regarded as, and transversal section is 1m ²expansion cylinder volume, this volume is hm ³/ hm ².On forest land, the h sum of each strain observation wood, is the volume of timber of standing forest per hectare.

Wherein trunk is as follows apart from the high computational mode on ground:

As Fig. 2, formula is as follows: have according to sine:

A/sin (a1)=B/sin θ=C/sin (180-a2)=2R (R is the external radius of a circle of triangle);

H/sin(a1-β)＝C/sin(β)

θ＝180-(180-a2+a1)

C＝(B/sinθ)*sin(180-a2)＝(B/sin(180-(180-a2+a1)))*sin(180-a2)

H＝([(B/sin(180-(180-a2+a)))*sin(180-a2)]/sin(β))*sin(a1-β)

Wherein, a1 is the angle of observation treetop, instrument height 1 place, and β is the angle at the instrument height 1 place observation tree end, and a2 is the angle of the treetop of instrument height 2 place observation.B is the difference of twice instrument height, generally gets B=instrument height 1-instrument height 2 > 1.0m.

This invention compared with prior art has the following advantages:

1. adopt regular handset to take pictures, light, flexible, period from practical measurement is short.

2. do not need the diameter of a cross-section of a tree trunk 1.3 meters above the ground measuring forest, reduce observation time.

3. measured data is by computer statistics, calculating, and interior industry workload is little, and efficiency is high.

Four, accompanying drawing explanation

Below in conjunction with drawings and Examples, the present invention is further described.

Fig. 1 is the diameter of a cross-section of a tree trunk 1.3 meters above the ground schematic diagram utilizing the assize of mobile phone subtended angle.

Fig. 2 is the schematic diagram of assize height.

Five, embodiment:

The method measuring stand volume based on mobile phone is different from existing method, has done significant improvement.Specifically: be instrument with regular handset, the software with assize function is installed in mobile phone, and the subtended angle θ arranging this assize software is 1 ° 08 ' 45 ".Utilize this subtended angle to aim at the diameter of a cross-section of a tree trunk 1.3 meters above the ground of tree, from sampling point around survey 360 °, observe that just the trunk at the tangent place of above trunk, apart from the height on ground, represents with h subtended angle with breastheight.The method calculating stand volume is as follows: the per hectare volume of timber (M) equals all trunks of each strain observation wood on forest land apart from floor level sum (in units of m), that is:

Embodiment is as follows:

1. assize software is installed in regular handset, this software function comprise subtended angle is set, assize is high.

2. with this regular handset for instrument, centered by certain sample ground, just the trunk at the tangent place of above trunk is apart from the height on ground with breastheight to observe subtended angle, and this height represents with h.

3. trunk is as follows apart from the metering system of floor level:

1. the position of the chosen distance trees 0.5-1.0 times height of tree is as observation station.

2. measure eye distance ground when oneself standing height (being generally height * 92%) and on one knee time eye distance ground the difference of height.Also special foot rest can be used to fix mobile phone to provide the instrument discrepancy in elevation between twice observation.

3. be inclined upwardly while keeping cell-phone camera grease head highness consistent with eye-level on one knee mobile phone, make camera aim at measured tree tip position, utilize alignment clamp crosshair on mobile phone screen, fine setting mobile phone swing, fine sight treetop portion, presses [record angle, treetop 1] button.

4. be inclined upwardly while maintenance cell-phone camera grease head highness of standing is consistent with eye-level mobile phone, make camera aim at position, measured tree top, utilize alignment clamp crosshair on mobile phone screen, fine setting mobile phone swing, fine sight treetop portion, presses [record angle, treetop 2] button.

5. downward-sloping mobile phone while maintenance cell-phone camera grease head highness of standing is consistent with eye-level, make camera aim at position at the bottom of measured tree, utilize alignment clamp crosshair on mobile phone screen, fine setting mobile phone swing, fine sight tree bottom, presses [record tree base angle 2] button.

6. press [the calculating height of tree] button and obtain the height of tree, horizontal range, angle, treetop 1, angle, treetop 2, the tree angle at base angle 2 record.

4., centered by this sampling point, from sampling point around survey 360 °, calculate the number of tree, be designated as n.

5. the per hectare volume of timber (M) equals the height sum (by m in units of) of trunk apart from ground of each strain observation wood on forest land, that is: $M=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{h}_i.$

Claims (2)

1. a mobile phone directly measures stand volume method, it is characterized in that: take regular handset as instrument, software with assize function is installed in mobile phone, point centered by the position at mobile phone place, and to arrange the horizontal subtended angle θ of this observation station be 1 ° 08 ' 45 ' ', screen differentiation line is set, at 0 ° within the scope of 360 °, use this subtended angle to break up line tangent with observation wooden somewhere trunk diameter, record calculates the height on distance ground, points of tangency place with h _irepresent, if the observation wood number observed is n.

2. observation procedure according to claim 1, calculates stand volume, and the per hectare volume of timber (M) equals the height sum (in units of m) of n strain observation wood, that is: