sinu.php
4.73 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
<?php
/**
* Author : Julien Moquet
*
* Inspired by Proj4php from Mike Adair madairATdmsolutions.ca
* and Richard Greenwood rich@greenwoodma$p->com
* License: LGPL as per: http://www.gnu.org/copyleft/lesser.html
*/
/*******************************************************************************
NAME SINUSOIDAL
PURPOSE: Transforms input longitude and latitude to Easting and
Northing for the Sinusoidal projection. The
longitude and latitude must be in radians. The Easting
and Northing values will be returned in meters.
PROGRAMMER DATE
---------- ----
D. Steinwand, EROS May, 1991
This function was adapted from the Sinusoidal projection code (FORTRAN) in the
General Cartographic Transformation Package software which is available from
the U.S. Geological Survey National Mapping Division.
ALGORITHM REFERENCES
1. Snyder, John P., "Map Projections--A Working Manual", U.S. Geological
Survey Professional Paper 1395 (Supersedes USGS Bulletin 1532), United
State Government Printing Office, Washington D.C., 1987.
2. "Software Documentation for GCTP General Cartographic Transformation
Package", U.S. Geological Survey National Mapping Division, May 1982.
* ***************************************************************************** */
class Proj4phpProjSinu {
/* Initialize the Sinusoidal projection
------------------------------------ */
public function init() {
/* Place parameters in static storage for common use
------------------------------------------------- */
#$this->R = 6370997.0; //Radius of earth
if( !$this->sphere ) {
$this->en = Proj4php::$common->pj_enfn( $this->es );
} else {
$this->n = 1.;
$this->m = 0.;
$this->es = 0;
$this->C_y = sqrt( ($this->m + 1.) / $this->n );
$this->C_x = $this->C_y / ($this->m + 1.);
}
}
/* Sinusoidal forward equations--mapping lat,long to x,y
----------------------------------------------------- */
public function forward( $p ) {
#$x,y,delta_lon;
$lon = $p->x;
$lat = $p->y;
/* Forward equations
----------------- */
$lon = Proj4php::$common->adjust_lon( $lon - $this->long0 );
if( isset($this->sphere) ) {
if( !$this->m ) {
$lat = $this->n != 1. ? asin( $this->n * sin( $lat ) ) : $lat;
} else {
$k = $this->n * sin( $lat );
for( $i = Proj4php::$common->MAX_ITER; $i; --$i ) {
$V = ($this->m * $lat + sin( $lat ) - $k) / ($this->m + cos( $lat ));
$lat -= $V;
if( abs( $V ) < Proj4php::$common->EPSLN )
break;
}
}
$x = $this->a * $this->C_x * $lon * ($this->m + cos( $lat ));
$y = $this->a * $this->C_y * $lat;
} else {
$s = sin( $lat );
$c = cos( $lat );
$y = $this->a * Proj4php::$common->pj_mlfn( $lat, $s, $c, $this->en );
$x = $this->a * $lon * $c / sqrt( 1. - $this->es * $s * $s );
}
$p->x = $x;
$p->y = $y;
return $p;
}
/**
*
* @param type $p
* @return type
*/
public function inverse( $p ) {
#$lat;
#$temp;
#$lon;
/* Inverse equations
----------------- */
$p->x -= $this->x0;
$p->y -= $this->y0;
$lat = $p->y / $this->a;
if( isset($this->sphere) ) {
$p->y /= $this->C_y;
$lat = $this->m ? asin( ($this->m * $p->y + sin( $p->y )) / $this->n ) : ( $this->n != 1. ? asin( sin( $p->y ) / $this->n ) : $p->y );
$lon = $p->x / ($this->C_x * ($this->m + cos( $p->y )));
}
else {
$lat = Proj4php::$common->pj_inv_mlfn( $p->y / $this->a, $this->es, $this->en );
$s = abs( $lat );
if( $s < Proj4php::$common->HALF_PI ) {
$s = sin( $lat );
$temp = $this->long0 + $p->x * sqrt( 1. - $this->es * $s * $s ) / ($this->a * cos( $lat ));
//temp = $this->long0 + $p->x / ($this->a * cos($lat));
$lon = Proj4php::$common->adjust_lon( $temp );
} else if( ($s - Proj4php::$common->EPSLN) < Proj4php::$common->HALF_PI ) {
$lon = $this->long0;
}
}
$p->x = $lon;
$p->y = $lat;
return $p;
}
}
Proj4php::$proj['sinu'] = new Proj4phpProjSinu();