| 1 |
kusanagi |
1.1 |
//
|
| 2 |
|
|
// cSite.cpp
|
| 3 |
|
|
//
|
| 4 |
|
|
// Copyright (c) 2003 Michael F. Henry
|
| 5 |
|
|
//
|
| 6 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 7 |
|
|
#include "stdafx.h"
|
| 8 |
|
|
#include "cSite.h"
|
| 9 |
|
|
#include "globals.h"
|
| 10 |
|
|
|
| 11 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 12 |
|
|
// Construction/Destruction
|
| 13 |
|
|
cSite::cSite(const cCoordGeo &geo) : m_geo(geo)
|
| 14 |
|
|
{}
|
| 15 |
|
|
|
| 16 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 17 |
|
|
// c'tor accepting:
|
| 18 |
|
|
// Latitude in degress (negative south)
|
| 19 |
|
|
// Longitude in degress (negative west)
|
| 20 |
|
|
// Altitude in km
|
| 21 |
|
|
cSite::cSite(double degLat, double degLon, double kmAlt) :
|
| 22 |
|
|
m_geo(deg2rad(degLat), deg2rad(degLon), kmAlt)
|
| 23 |
|
|
{}
|
| 24 |
|
|
|
| 25 |
|
|
cSite::~cSite()
|
| 26 |
|
|
{}
|
| 27 |
|
|
|
| 28 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 29 |
|
|
// setGeo()
|
| 30 |
|
|
// Set a new geographic position
|
| 31 |
|
|
void cSite::setGeo(const cCoordGeo &geo)
|
| 32 |
|
|
{
|
| 33 |
|
|
m_geo = geo;
|
| 34 |
|
|
}
|
| 35 |
|
|
|
| 36 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 37 |
|
|
// getPosition()
|
| 38 |
|
|
// Return the ECI coordinate of the site at the given time.
|
| 39 |
|
|
cEci cSite::getPosition(const cJulian &date) const
|
| 40 |
|
|
{
|
| 41 |
|
|
return cEci(m_geo, date);
|
| 42 |
|
|
}
|
| 43 |
|
|
|
| 44 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 45 |
|
|
// getLookAngle()
|
| 46 |
|
|
// Return the topocentric (azimuth, elevation, etc.) coordinates for a target
|
| 47 |
|
|
// object described by the input ECI coordinates.
|
| 48 |
|
|
cCoordTopo cSite::getLookAngle(const cEci &eci) const
|
| 49 |
|
|
{
|
| 50 |
|
|
// Calculate the ECI coordinates for this cSite object at the time
|
| 51 |
|
|
// of interest.
|
| 52 |
|
|
cJulian date = eci.getDate();
|
| 53 |
|
|
cEci eciSite(m_geo, date);
|
| 54 |
|
|
|
| 55 |
|
|
// The Site ECI units are km-based; ensure target ECI units are same
|
| 56 |
|
|
assert(eci.UnitsAreKm());
|
| 57 |
|
|
|
| 58 |
|
|
cVector vecRgRate(eci.getVel().m_x - eciSite.getVel().m_x,
|
| 59 |
|
|
eci.getVel().m_y - eciSite.getVel().m_y,
|
| 60 |
|
|
eci.getVel().m_z - eciSite.getVel().m_z);
|
| 61 |
|
|
|
| 62 |
|
|
double x = eci.getPos().m_x - eciSite.getPos().m_x;
|
| 63 |
|
|
double y = eci.getPos().m_y - eciSite.getPos().m_y;
|
| 64 |
|
|
double z = eci.getPos().m_z - eciSite.getPos().m_z;
|
| 65 |
|
|
double w = sqrt(sqr(x) + sqr(y) + sqr(z));
|
| 66 |
|
|
|
| 67 |
|
|
cVector vecRange(x, y, z, w);
|
| 68 |
|
|
|
| 69 |
|
|
// The site's Local Mean Sidereal Time at the time of interest.
|
| 70 |
|
|
double theta = date.toLMST(getLon());
|
| 71 |
|
|
|
| 72 |
|
|
double sin_lat = sin(getLat());
|
| 73 |
|
|
double cos_lat = cos(getLat());
|
| 74 |
|
|
double sin_theta = sin(theta);
|
| 75 |
|
|
double cos_theta = cos(theta);
|
| 76 |
|
|
|
| 77 |
|
|
double top_s = sin_lat * cos_theta * vecRange.m_x +
|
| 78 |
|
|
sin_lat * sin_theta * vecRange.m_y -
|
| 79 |
|
|
cos_lat * vecRange.m_z;
|
| 80 |
|
|
double top_e = -sin_theta * vecRange.m_x +
|
| 81 |
|
|
cos_theta * vecRange.m_y;
|
| 82 |
|
|
double top_z = cos_lat * cos_theta * vecRange.m_x +
|
| 83 |
|
|
cos_lat * sin_theta * vecRange.m_y +
|
| 84 |
|
|
sin_lat * vecRange.m_z;
|
| 85 |
|
|
double az = atan(-top_e / top_s);
|
| 86 |
|
|
|
| 87 |
|
|
if (top_s > 0.0)
|
| 88 |
|
|
az += PI;
|
| 89 |
|
|
|
| 90 |
|
|
if (az < 0.0)
|
| 91 |
|
|
az += 2.0*PI;
|
| 92 |
|
|
|
| 93 |
|
|
double el = asin(top_z / vecRange.m_w);
|
| 94 |
|
|
double rate = (vecRange.m_x * vecRgRate.m_x +
|
| 95 |
|
|
vecRange.m_y * vecRgRate.m_y +
|
| 96 |
|
|
vecRange.m_z * vecRgRate.m_z) / vecRange.m_w;
|
| 97 |
|
|
|
| 98 |
|
|
cCoordTopo topo(az, // azimuth, radians
|
| 99 |
|
|
el, // elevation, radians
|
| 100 |
|
|
vecRange.m_w, // range, km
|
| 101 |
|
|
rate); // rate, km / sec
|
| 102 |
|
|
|
| 103 |
|
|
#ifdef WANT_ATMOSPHERIC_CORRECTION
|
| 104 |
|
|
// Elevation correction for atmospheric refraction.
|
| 105 |
|
|
// Reference: Astronomical Algorithms by Jean Meeus, pp. 101-104
|
| 106 |
|
|
// Note: Correction is meaningless when apparent elevation is below horizon
|
| 107 |
|
|
topo.m_El += deg2rad((1.02 /
|
| 108 |
|
|
tan(deg2rad(rad2deg(el) + 10.3 /
|
| 109 |
|
|
(rad2deg(el) + 5.11)))) / 60.0);
|
| 110 |
|
|
if (topo.m_El < 0.0)
|
| 111 |
|
|
topo.m_El = el; // Reset to true elevation
|
| 112 |
|
|
|
| 113 |
|
|
if (topo.m_El > (PI / 2))
|
| 114 |
|
|
topo.m_El = (PI / 2);
|
| 115 |
|
|
#endif
|
| 116 |
|
|
|
| 117 |
|
|
return topo;
|
| 118 |
|
|
}
|
| 119 |
|
|
|
| 120 |
|
|
//////////////////////////////////////////////////////////////////////////////
|
| 121 |
|
|
// toString()
|
| 122 |
|
|
//
|
| 123 |
|
|
string cSite::toString() const
|
| 124 |
|
|
{
|
| 125 |
|
|
const int TEMP_SIZE = 128;
|
| 126 |
|
|
char sz[TEMP_SIZE];
|
| 127 |
|
|
|
| 128 |
|
|
bool LatNorth = true;
|
| 129 |
|
|
bool LonEast = true;
|
| 130 |
|
|
|
| 131 |
|
|
if (m_geo.m_Lat < 0.0)
|
| 132 |
|
|
{
|
| 133 |
|
|
LatNorth = false;
|
| 134 |
|
|
}
|
| 135 |
|
|
|
| 136 |
|
|
if (m_geo.m_Lon < 0.0)
|
| 137 |
|
|
{
|
| 138 |
|
|
LonEast = false;
|
| 139 |
|
|
}
|
| 140 |
|
|
|
| 141 |
|
|
snprintf(sz, TEMP_SIZE,
|
| 142 |
|
|
"%06.3f%c, ",
|
| 143 |
|
|
fabs(rad2deg(m_geo.m_Lat)),
|
| 144 |
|
|
(LatNorth ? 'N' : 'S'));
|
| 145 |
|
|
|
| 146 |
|
|
string strLoc = sz;
|
| 147 |
|
|
|
| 148 |
|
|
snprintf(sz, TEMP_SIZE,
|
| 149 |
|
|
"%07.3f%c, ",
|
| 150 |
|
|
fabs(rad2deg(m_geo.m_Lon)),
|
| 151 |
|
|
(LonEast ? 'E' : 'W'));
|
| 152 |
|
|
strLoc += sz;
|
| 153 |
|
|
|
| 154 |
|
|
snprintf(sz, TEMP_SIZE,
|
| 155 |
|
|
"%.1fm\n",
|
| 156 |
|
|
(m_geo.m_Alt * 1000.0));
|
| 157 |
|
|
strLoc += sz;
|
| 158 |
|
|
|
| 159 |
|
|
return strLoc;
|
| 160 |
|
|
}
|
| 161 |
|
|
|
Parent Directory
| 
Revision Log