[SOLVED] C android math 36 10

36 10
2016 10 Journal of Central South University of Forestry & Technology
Doi:10.14067/j.cnki.1673-923x.2016.10.014
Vol.36 No.10 Oct. 2016
http: //qks.csuft.edu.cn
Android APP
1221 2 (1. 100042;2. 100083)
:Android Android , (Blume-Leiss) APP 3.19; (Blume-Leiss) 3.70 APP 62%
:;Android;;
:S758.5 :A :1673-923X(2016)10-0078-05
Development and test of android smartphone tree height measurement APP
LI Ya-dong1,2, FENG Zhong-ke2, CAO Ming-lan1, ZHENG Fan2
(1.Beijing Polytechnic College, Beijing 100042,China; 2.Beijing Key Laboratory of Precision Forestry of Beijing Forestry University, Beijing 100083, China)
Abstract: With its strong advantages of openness and flexibility, Android mobile phone system becomes the necessary choice of mobile phone system application development. The article discusses technical points and the practice process of developing individual tree height measurement program based on Android mobile phone system sensor and through experiment, compares and analyzes measurement results and traditional Blume-Leiss height finder. Results show that Android tree height measurement APP has the average error of 3.19; Blume-Leiss height finder has the average error of 3.70. Average error precision of Android phone tree height measurement APP method increases by 62% than that of the latter.
Key words: forestry; android; sensor; measurements
[1] [2] [3-4] [5] [6-7]PDA [8]Android

[9] [10-11] Android APP APP
:2015-06-19
:(41371001)
: :;E-mail:[email protected] : . Android APP [J]. 2016,36(10):78-82.

36 79 1 Android
1.1 Android
[12] Android4.0 13
Android API( )
Z XZXY 1 X Y Z Z API
1
Fig.1 Standard 3D space coordinate system
1.2

(1) 2: H=h+l (1) D=cosl (2)
Fig.2
2
Tree height measurement principle diagram of flat area and uniform slope
h=tanD (3)
H=tancosl (4) :H h D l 90 90
(2)

(3)
A B C 2R
sin1 sin sin 2
HC (5)
sin(1 -) sin =a1+a2
C Bsin2 Bsin2 (6) sin sin(2 -1)
H Bsin2 sin(1 -) (7) sin(2 -1)sin
:a1 1 1 a2 2 B B= 1-2>1.0 m
3
Fig.3 Schematic diagram of tree height measurement

80 2
:Android APP 10
Android APP
}
}
publicclassMyViewextends View
implementsSensorEventListener {

publicvoidonSensorChanged(SensorEvent event)
// TODO Auto-generated method stub
// x = event.values[0]; x
// y = event.values[1]; y
// z = event.values[2]; z
if (event.sensor.getType() == Sensor.TYPE_
Android
2.1 APP
getSystemService() SENSOR_ SERVICE SensorManager View SurfaceView :
publicclass Main extends Activity { privateSurfaceViewsurfaceview; privateMyViewmyView;
private Camera camera; publicvoidonCreate(Bundle savedInstanceState)
{

{
ACCELEROMETER) {
// z
z = event.values[2];
// acos(zc/ 10) double r = Math.acos(z / 10);
//
double degree = (double) (r * 180 / Math.PI);
}
2.2.1 (1) 0.5 ~ 1.0
(2)
(3)
(4)
( X Y )
(5) ( X Y )
(6)
2.2.2 :
(1) 0.5 ~ 1.0
surfaceview = (SurfaceView) findViewById(R. id.preview);

// SensorManager m_sensorManager = this.getSystemService
(SENSOR_SERVICE) as SensorManager;

myView = newMyView(this, display.widthPixels, display.heightPixels);

}
SurfaceHolder.Callbackm_surfaceCalback = newSurfaceHolder.Callback() {
//
camera = Camera.open();
}
publicvoidsurfaceChanged(SurfaceHolder holder,
int format, int width, int height) {

// camera.startPreview();

}
2.2

36 81
( 4);
4
Fig.4 Observation method diagram of uniform slope
2.2.3 : (1) 0.5 ~ 1.0
(2)(
92%)
(3) ( X Y ) 1
(4) ( X Y ) 2
(5) ( X Y ) 2
(6) 1 2 2
3 3.1

NTS-352L ( 3 mm+210-6D 2) (Blume-Leiss) A808T APP( 5) (Blume-Leiss) A808T APP 10 (Blume-Leiss) A808T APP (8)
I=(|H-Ht|)/Ht (8) (8):I ;H ;Ht ;
Fig.5
3.2
30 10 (Blume-Leiss) A808T APP 1
2 n
n APP 3.19; (Blume-Leiss) 3.70 30 10 62%
4
Android APP
5
Android phone tree height measurement APP
Android APP interface

:Android APP 10 1 APP(Blume-Leiss)
Relative error comparison of android phone tree height measurement APP andBlume-Leiss height finder
APP APP /m /m /% /m /% /m /m /% /m /%
1 7.89 7.63 3.30 7.65 3.04 17 5.02 5.22 -3.98 4.88 2.79 2 7.75 7.95 -2.58 7.83 -1.03 18 7.31 7.61 -4.10 7.52 -2.87 3 7.36 7.66 -4.08 7.62 -3.53 19 10.65 11.03 -3.57 10.49 1.50 4 8.28 7.98 3.62 8.11 2.05 20 6.84 7.15 -4.53 6.75 1.32 5 7.70 7.98 -3.64 7.83 -1.69 21 13.76 13.46 2.18 13.25 3.71 6 10.74 11.18 -4.10 10.98 -2.23 22 11.76 11.56 1.70 12.03 -2.30 7 10.41 10.01 3.84 10.67 -2.50 23 7.09 6.93 2.26 7.40 -4.37 8 7.82 7.61 2.69 8.02 -2.56 24 10.61 10.11 4.71 10.38 2.17 9 15.54 15.95 -2.64 15.32 1.42 25 12.50 12.90 -3.20 11.89 4.88
10 14.02 13.62 2.85 13.78 1.71 26 12.50 11.90 4.80 12.09 3.28 11 8.25 8.55 -3.64 8.65 -4.85 27 7.22 6.92 4.16 7.35 -1.80 12 7.31 6.98 4.51 6.95 4.92 28 10.87 11.12 -2.30 11.41 -4.97 13 7.37 7.07 4.07 7.18 2.58 29 9.41 8.98 4.57 9.21 2.13 14 7.78 8.08 -3.86 8.05 -3.47 30 7.70 8.03 -4.29 8.07 -4.81 15 7.45 7.15 4.03 7.13 4.30 9.19 9.20 0.24 9.16 0.09 16 6.68 6.39 4.34 6.42 3.89
82
Table 1

(Blume-Leiss) A808T APP APP 3.19;(Blume- Leiss) 3.70 APP (Blume-Leiss) 62%
:
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