By Paul Dixon
Has no other scripts.
/*
Geocaching OS Linker - 0.50 14/07/2005
Copyright (c) 2005, Paul Dixon <paul@elphin.com>
Released under the GPL http://www.gnu.org/copyleft/gpl.html
This is a Greasemonkey user script, see http://greasemonkey.mozdev.org/.
This provides cache information pages with links to OS Maps for UK
caches, and links to Google Maps and Google Earth for everyone. It
also changes the OS Get-a-Map popup to include an indicator arrow for
the cache position.
The parseGridRef function is an adaptation of code Neil Jones
wrote for his map substitution script.
*/
// ==UserScript==
// @name Geocaching Map Linker
// @namespace http://files.dixo.net
// @description Links cache pages to maps, e.g. Google Maps and UK Ordnance Survey
// @include http://www.geocaching.com/seek/cache_details.aspx*
// @include http://getamap.ordnancesurvey.co.uk/getamap/map.htm
// ==/UserScript==
//get position of a DOM element
//(from http://www.quirksmode.org/js/findpos.html)
window._findPosX=function(obj)
{
var curleft = 0;
if (obj.offsetParent)
{
while (obj.offsetParent)
{
curleft += obj.offsetLeft
obj = obj.offsetParent;
}
}
else if (obj.x)
curleft += obj.x;
return curleft;
}
window._findPosY=function(obj)
{
var curtop = 0;
if (obj.offsetParent)
{
while (obj.offsetParent)
{
curtop += obj.offsetTop
obj = obj.offsetParent;
}
}
else if (obj.y)
curtop += obj.y;
return curtop;
}
//get url to OS Get-a-Map
window._getOSMapUrl=function(gridref)
{
if (gridref.length > 0)
return 'http://getamap.ordnancesurvey.co.uk/getamap/frames.htm?mapAction=gaz&gazName=g&gazString='+gridref;
else
return 'http://getamap.ordnancesurvey.co.uk/getamap/frames.htm';
}
//display a OS Get-a-Map popup
window._popupOSMap=function(gridref)
{
//remember the grid ref
GM_setValue('gridref', gridref);
var wWidth = 740;
var wHeight = 520;
var wLeft = Math.round(0.5 * (screen.availWidth - wWidth));
var wTop = Math.round(0.5 * (screen.availHeight - wHeight)) - 20;
var url=window._getOSMapUrl(gridref);
var newWin = window.open(url,
'gam',
'left='+wLeft+',screenX='+wLeft+',top='+wTop+',screenY='+wTop+',width='+wWidth+',height='+wHeight+',status,scrolling=no');
newWin.focus();
}
window.getOSMapAnchor=function(gridref, text,title)
{
var url=window._getOSMapUrl(gridref);
return '<a target="_blank" title="'+title+'" href="'+url+'" onclick="window._popupOSMap(\''+gridref+'\');return false;">'+text+'</a>';
}
window.getGoogleEarthLinkUrl=function(latitude, longitude, name, desc)
{
//build the kml data
var kml=new String;
kml='<?xml version="1.0" encoding="UTF-8"?>';
kml=kml+'<kml xmlns="http://earth.google.com/kml/2.0">';
kml=kml+'<Placemark>';
kml=kml+'<name><![CDATA['+name+']]></name>';
desc=desc+'<br><a href="'+document.location+'">Cache Details</a>';
kml=kml+'<description><![CDATA['+desc+']]></description>';
kml=kml+'<styleUrl>#geocache</styleUrl>';
kml=kml+'<Style id="geocache"><IconStyle><Icon>';
kml=kml+'<href>root://icons/palette-2.png</href>';
kml=kml+'<x>160</x><y>192</y><w>32</w><h>32</h>';
kml=kml+'</Icon></IconStyle></Style>';
kml=kml+'<Point>';
kml=kml+'<coordinates>'+longitude+','+latitude+',0</coordinates>';
kml=kml+'</Point>';
kml=kml+'</Placemark>';
kml=kml+'</kml>';
//data:[<mediatype>][;base64],<data>
return "data:application/vnd.google-earth.kml+xml,"+encodeURIComponent(kml);
}
window.getGoogleEarthAnchor=function(latitude, longitude, name, desc, text, title)
{
var url=window.getGoogleEarthLinkUrl(latitude, longitude, name, desc);
return '<a href="'+url+'" title="'+title+'">'+text+'</a>';
}
window.getGoogleMapUrl=function(latitude, longitude, sat)
{
var url="http://maps.google.com/?q="+latitude+"%2C"+longitude;
if (sat)
{
url=url+"&spn=0.055120,0.055120&t=k";
}
return url
}
window.getGoogleMapAnchor=function(latitude, longitude, sat, text, title)
{
var url=window.getGoogleMapUrl(latitude, longitude, sat);
return '<a href="'+url+'" title="'+title+'">'+text+'</a>';
}
//this is called to enhance a geocaching.com cache listing page with OS Get-a-Map links
//and Google Maps links
window.enhanceGeocacheListing=function()
{
var isUK=false;
//<span id="UTMFormat">British Grid: TL 11855 26471<br /><font size=2><img src="../images/icons/compass/SW.gif" alt="SW" title="SW" border=0>SW 8.9mi from your home coordinates.<br /></font></span>
var UTMFormat = document.getElementById("UTMFormat");
if (UTMFormat)
{
var pattern = /British Grid: ([A-Z]{2}) (\d{5}) (\d{5})/;
var matches=UTMFormat.innerHTML.match(pattern);
if (matches)
{
isUK=true;
var gridref=matches[1]+matches[2]+matches[3];
//store grid reference - GreaseMonkey'd Get-a-Map picks this up
GM_setValue('gridref', gridref);
var maplink=window.getOSMapAnchor(gridref, matches[1]+' '+matches[2]+' '+matches[3],'Click for OS Map');
UTMFormat.innerHTML =
UTMFormat.innerHTML.replace(pattern,
'British Grid '+maplink);
}
}
//collect useful information about the cache
//<title>(GCH8TJ) In the shadow of the Tower by Cookiecachers</title>
var titlepattern = /^\(.*?\) (.*) by .*$/;
var matches=document.title.match(titlepattern);
var cachename=matches[1];
var spanShort=document.getElementById("ShortDescription");
var shortdesc="";
if (spanShort)
{
shortdesc=spanShort.innerHTML;
}
//<a id="linkJeeep" href="http://www.jeeep.com/details/coord/translate.cgi?datum=83&lat=51.9255&lon=-0.374733&detail=1"
var linkJeeep = document.getElementById("linkJeeep");
if (linkJeeep && UTMFormat)
{
//alert(linkJeeep.href);
var pattern = /lat=(-?[\d\.]+).*lon=(-?[\d\.]+)/;
var matches=linkJeeep.href.match(pattern);
if (matches)
{
var latitude=matches[1];
var longitude=matches[2];
var linkGMap=window.getGoogleMapAnchor(latitude, longitude, false, 'Google Map', 'Click for Google Map');
var linkGSat=window.getGoogleMapAnchor(latitude, longitude, true, '(inc Satellite)', 'Click for Google Map with Satellite Images (if available)');
var linkGEarth=window.getGoogleEarthAnchor(latitude, longitude, cachename, shortdesc, 'Google Earth', 'Click to open Google Earth waypoint');
UTMFormat.innerHTML=linkGMap+" "+linkGSat+" "+linkGEarth+"<br/>"+UTMFormat.innerHTML;
}
}
//lets see if we can hyperlink any other mentioned coordinates to a map
var spanLong=document.getElementById("LongDescription");
if (spanLong)
{
var longdesc=spanLong.innerHTML;
//match N52 03.270 W000 17.675
longdesc=longdesc.replace(/([ns])\s*(\d+)[ð\s]+(\d+\.\d+)\s+([we])\s*(\d+)[ð\s]+(\d+\.\d+)/ig,
function (match, lat1,lat2,lat3,long1,long2,long3)
{
var reformatted=match;
var wgs84=new GT_WGS84();
if (wgs84.parseString(match))
{
if (wgs84.isGreatBritain())
{
//link to OSGB map
var osgb=wgs84.getOSGB();
var gridref=osgb.getGridRef(5);
var anchor=window.getOSMapAnchor(gridref, '<span style="font-size:small;">[map]</span>','Click for OS Map');
reformatted=match+ " "+anchor;
}
else
{
//link to google maps
}
}
return reformatted;
}
);
spanLong.innerHTML=longdesc;
}
}
//this is called to enhance OS Get-a-Map - it overrides some of their
//JS functions with cheeky monkey versions
window.enhanceOSMap=function()
{
window.original_updateInfo=updateInfo;
updateInfo=window.super_updateInfo;
window.original_setRetImg=setRetImg;
setRetImg=window.super_setRetImg;
}
//Get-A-Map calls this to hide the map, we take opportunity to hide our
//indicator marker too...
window.super_setRetImg=function()
{
var result=window.original_setRetImg();
//hide our marker
var indicator=document.getElementById('monkeymagic');
if (indicator)
{
indicator.style.display='none';
}
return result;
}
//Get-A-Map calls this to update the display, so we do the magic to place an
//indicator marker onto the map
window.super_updateInfo=function(winWid, srcDat, coordStr, lastSearch, a, b, c, d, e)
{
//GM_log("winWid="+winWid+" srcDat="+srcDat+" coordStr="+coordStr+" lastSearch="+lastSearch+" a="+a+" b="+b+" c="+c+" d="+d+" e="+e);
//call original function
var result=window.original_updateInfo(winWid, srcDat, coordStr, lastSearch, a, b, c, d, e);
//get grid reference to plot
var gridref=GM_getValue('gridref', '');
if (gridref.length)
{
var osgb=new GT_OSGB();
osgb.parseGridRef(gridref);
//for TL1801127713
//gives 520737, 226196
//should be 518011, 227713
//out by 2726,-1517
//GM_log("gridref="+gridref);
//get the info original code pasted in
var mapInfo=document.getElementById('mapInfo')
var info=mapInfo.innerHTML;
//parse the scale
var metres_per_pixel=5;
var pattern = /Window width - (\d+) km/;
if (matches=info.match(pattern))
{
var w=parseInt(matches[1]);
metres_per_pixel=(w*1000)/400;
}
//GM_log("metres per pixel "+metres_per_pixel);
//point 0,0 on the image can be obtained from the OS script
//variables minX,maxY - frm this we can work out the offset
//in metres to the indicator point
var mx=osgb.eastings - window.minX;
var my=window.maxY - osgb.northings;
//GM_log("osgb.eastings="+osgb.eastings+" osgb.northings="+osgb.northings);
//GM_log("minX="+window.minX+" maxY="+window.maxY);
//GM_log("mx="+mx+" my="+my);
//and now it's just a simple conversion to pixels
var px=mx/metres_per_pixel;
var py=my/metres_per_pixel;
//get the map img and calculate the absolute position of our marker
var mapImg = document.images['imgMap'];
var imgx=window._findPosX(mapImg) + px;
var imgy=window._findPosY(mapImg) +py;
var indicator=document.getElementById('monkeymagic');
if (!indicator)
{
//create our indicator - a transparent image, absolutely positioned
indicator=document.createElement('img');
indicator.src='data:image/gif,GIF89a%0D%00%0D%00%80%00%00%FF%00%00%FF%FF%FF!%F9%04%01%00%00%01%00%2C%00%00%00%00%0D%00%0D%00%00%02%1A%84%8F%A9%18%CB%ED%40%98q%D2zq%3Cp%A7%CEp%99qY%99%25%99%94Y%00%00%3B';
indicator.id='monkeymagic';
indicator.style.position="absolute";
indicator.style.display='none';
//insert into document
mapInfo.parentNode.insertBefore(indicator, mapInfo);
}
//set the indicator position
indicator.style.top=imgy;
indicator.style.left=imgx;
indicator.style.display='';
}
return result;
}
/*****************************************************************************
*
* GeoTools script inlined here....
* Contact paul@elphin.com for most recent version of this script...
*
*****************************************************************************/
/*****************************************************************************
*
* GT_OSGB holds OSGB grid coordinates
*
*****************************************************************************/
function GT_OSGB()
{
this.northings=0;
this.eastings=0;
this.status="Undefined";
}
GT_OSGB.prefixes = new Array (
new Array("SV","SW","SX","SY","SZ","TV","TW"),
new Array("SQ","SR","SS","ST","SU","TQ","TR"),
new Array("SL","SM","SN","SO","SP","TL","TM"),
new Array("SF","SG","SH","SJ","SK","TF","TG"),
new Array("SA","SB","SC","SD","SE","TA","TB"),
new Array("NV","NW","NX","NY","NZ","OV","OW"),
new Array("NQ","NR","NS","NT","NU","OQ","OR"),
new Array("NL","NM","NN","NO","NP","OL","OM"),
new Array("NF","NG","NH","NJ","NK","OF","OG"),
new Array("NA","NB","NC","ND","NE","OA","OB"),
new Array("HV","HW","HX","HY","HZ","JV","JW"),
new Array("HQ","HR","HS","HT","HU","JQ","JR"),
new Array("HL","HM","HN","HO","HP","JL","JM"));
GT_OSGB.prototype.setGridCoordinates = function(eastings,northings)
{
this.northings=northings;
this.eastings=eastings;
this.status="OK";
}
GT_OSGB.prototype.setError = function(msg)
{
this.status=msg;
}
GT_OSGB.prototype._zeropad = function(num, len)
{
var str=new String(num);
while (str.length<len)
{
str='0'+str;
}
return str;
}
GT_OSGB.prototype.getGridRef = function(precision)
{
if (precision<0)
precision=0;
if (precision>5)
precision=5;
var e="";
var n="";
if (precision>0)
{
var y=Math.floor(this.northings/100000);
var x=Math.floor(this.eastings/100000);
var e=Math.round(this.eastings%100000);
var n=Math.round(this.northings%100000);
var div=(5-precision);
e=Math.round(e / Math.pow(10, div));
n=Math.round(n / Math.pow(10, div));
}
var prefix=GT_OSGB.prefixes[y][x];
return prefix+this._zeropad(e, precision)+this._zeropad(n, precision);
}
GT_OSGB.prototype.parseGridRef = function(landranger)
{
var ok=false;
this.northings=0;
this.eastings=0;
var precision;
for (precision=5; precision>=1; precision--)
{
var pattern = new RegExp("^([A-Z]{2})\\s*(\\d{"+precision+"})\\s*(\\d{"+precision+"})$", "i")
var gridRef = landranger.match(pattern);
if (gridRef)
{
var gridSheet = gridRef[1];
var gridEast=0;
var gridNorth=0;
//5x1 4x10 3x100 2x1000 1x10000
if (precision>0)
{
var mult=Math.pow(10, 5-precision);
gridEast=parseInt(gridRef[2],10) * mult;
gridNorth=parseInt(gridRef[3],10) * mult;
}
var x,y;
search: for(y=0; y<GT_OSGB.prefixes.length; y++)
{
for(x=0; x<GT_OSGB.prefixes[y].length; x++)
if (GT_OSGB.prefixes[y][x] == gridSheet) {
this.eastings = (x * 100000)+gridEast;
this.northings = (y * 100000)+gridNorth;
ok=true;
break search;
}
}
}
}
return ok;
}
GT_OSGB.prototype.getWGS84 = function()
{
var height = 0;
var lat1 = GT_Math.E_N_to_Lat (this.eastings,this.northings,6377563.396,6356256.910,400000,-100000,0.999601272,49.00000,-2.00000);
var lon1 = GT_Math.E_N_to_Long(this.eastings,this.northings,6377563.396,6356256.910,400000,-100000,0.999601272,49.00000,-2.00000);
var x1 = GT_Math.Lat_Long_H_to_X(lat1,lon1,height,6377563.396,6356256.910);
var y1 = GT_Math.Lat_Long_H_to_Y(lat1,lon1,height,6377563.396,6356256.910);
var z1 = GT_Math.Lat_H_to_Z (lat1, height,6377563.396,6356256.910);
var x2 = GT_Math.Helmert_X(x1,y1,z1,446.448 ,0.2470,0.8421,-20.4894);
var y2 = GT_Math.Helmert_Y(x1,y1,z1,-125.157,0.1502,0.8421,-20.4894);
var z2 = GT_Math.Helmert_Z(x1,y1,z1,542.060 ,0.1502,0.2470,-20.4894);
var latitude = GT_Math.XYZ_to_Lat(x2,y2,z2,6378137.000,6356752.313);
var longitude = GT_Math.XYZ_to_Long(x2,y2);
var wgs84=new GT_WGS84();
wgs84.setDegrees(latitude, longitude);
return wgs84;
}
/*****************************************************************************
*
* GT_WGS84 holds WGS84 latitude and longitude
*
*****************************************************************************/
function GT_WGS84()
{
this.latitude=0;
this.longitude=0;
}
GT_WGS84.prototype.setDegrees = function(latitude,longitude)
{
this.latitude=latitude;
this.longitude=longitude;
}
GT_WGS84.prototype.parseString = function(text)
{
var ok=false;
var str=new String(text);
//N 51ð 53.947 W 000ð 10.018
var pattern = /([ns])\s*(\d+)[ð\s]+(\d+\.\d+)\s+([we])\s*(\d+)[ð\s]+(\d+\.\d+)/i;
var matches=str.match(pattern);
if (matches)
{
ok=true;
var latsign=(matches[1]=='s' || matches[1]=='S')?-1:1;
var longsign=(matches[4]=='w' || matches[4]=='W')?-1:1;
var d1=parseFloat(matches[2]);
var m1=parseFloat(matches[3]);
var d2=parseFloat(matches[5]);
var m2=parseFloat(matches[6]);
this.latitude=latsign * (d1 + (m1/60.0));
this.longitude=longsign * (d2 + (m2/60.0));
}
return ok;
}
GT_WGS84.prototype.isGreatBritain = function()
{
return this.latitude > 49 &&
this.latitude < 62 &&
this.longitude > -9.5 &&
this.longitude < 2.3;
}
GT_WGS84.prototype.isIreland = function()
{
return this.latitude > 51.2 &&
this.latitude < 55.73 &&
this.longitude > -12.2 &&
this.longitude < -4.8;
}
GT_WGS84.prototype.getOSGB = function()
{
var osgb=new GT_OSGB();
if (this.isGreatBritain())
{
var height = 0;
var x1 = GT_Math.Lat_Long_H_to_X(this.latitude,this.longitude,height,6378137.00,6356752.313);
var y1 = GT_Math.Lat_Long_H_to_Y(this.latitude,this.longitude,height,6378137.00,6356752.313);
var z1 = GT_Math.Lat_H_to_Z (this.latitude, height,6378137.00,6356752.313);
var x2 = GT_Math.Helmert_X(x1,y1,z1,-446.448,-0.2470,-0.8421,20.4894);
var y2 = GT_Math.Helmert_Y(x1,y1,z1, 125.157,-0.1502,-0.8421,20.4894);
var z2 = GT_Math.Helmert_Z(x1,y1,z1,-542.060,-0.1502,-0.2470,20.4894);
var latitude2 = GT_Math.XYZ_to_Lat (x2,y2,z2,6377563.396,6356256.910);
var longitude2 = GT_Math.XYZ_to_Long(x2,y2);
var e = GT_Math.Lat_Long_to_East (latitude2,longitude2,6377563.396,6356256.910,400000,0.999601272,49.00000,-2.00000);
var n = GT_Math.Lat_Long_to_North(latitude2,longitude2,6377563.396,6356256.910,400000,-100000,0.999601272,49.00000,-2.00000);
osgb.setGridCoordinates(Math.round(e), Math.round(n));
}
else
{
osgb.setError("Coordinate not within Great Britain");
}
return osgb;
}
/*****************************************************************************
*
* GT_Math is a collection of static methods doing all the nasty sums
*
*****************************************************************************/
//GT_Math is just namespace for all the nasty maths functions
function GT_Math()
{
}
GT_Math.E_N_to_Lat = function(East, North, a, b, e0, n0, f0, PHI0, LAM0)
{
//Un-project Transverse Mercator eastings and northings back to latitude.
//Input: - _
//eastings (East) and northings (North) in meters; _
//ellipsoid axis dimensions (a & b) in meters; _
//eastings (e0) and northings (n0) of false origin in meters; _
//central meridian scale factor (f0) and _
//latitude (PHI0) and longitude (LAM0) of false origin in decimal degrees.
//'REQUIRES THE "Marc" AND "InitialLat" FUNCTIONS
//Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI0 = PHI0 * (Pi / 180);
var RadLAM0 = LAM0 * (Pi / 180);
//Compute af0, bf0, e squared (e2), n and Et
var af0 = a * f0;
var bf0 = b * f0;
var e2 = (Math.pow(af0,2) - Math.pow(bf0,2)) / Math.pow(af0,2);
var n = (af0 - bf0) / (af0 + bf0);
var Et = East - e0;
//Compute initial value for latitude (PHI) in radians
var PHId = GT_Math.InitialLat(North, n0, af0, RadPHI0, n, bf0);
//Compute nu, rho and eta2 using value for PHId
var nu = af0 / (Math.sqrt(1 - (e2 * ( Math.pow(Math.sin(PHId),2)))));
var rho = (nu * (1 - e2)) / (1 - (e2 * Math.pow(Math.sin(PHId),2)));
var eta2 = (nu / rho) - 1;
//Compute Latitude
var VII = (Math.tan(PHId)) / (2 * rho * nu);
var VIII = ((Math.tan(PHId)) / (24 * rho * Math.pow(nu,3))) * (5 + (3 * (Math.pow(Math.tan(PHId),2))) + eta2 - (9 * eta2 * (Math.pow(Math.tan(PHId),2))));
var IX = ((Math.tan(PHId)) / (720 * rho * Math.pow(nu,5))) * (61 + (90 * ((Math.tan(PHId)) ^ 2)) + (45 * (Math.pow(Math.tan(PHId),4))));
var E_N_to_Lat = (180 / Pi) * (PHId - (Math.pow(Et,2) * VII) + (Math.pow(Et,4) * VIII) - ((Et ^ 6) * IX));
return (E_N_to_Lat);
}
GT_Math.E_N_to_Long = function(East, North, a, b, e0, n0, f0, PHI0, LAM0)
{
//Un-project Transverse Mercator eastings and northings back to longitude.
//Input: - _
//eastings (East) and northings (North) in meters; _
//ellipsoid axis dimensions (a & b) in meters; _
//eastings (e0) and northings (n0) of false origin in meters; _
//central meridian scale factor (f0) and _
//latitude (PHI0) and longitude (LAM0) of false origin in decimal degrees.
//REQUIRES THE "Marc" AND "InitialLat" FUNCTIONS
//Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI0 = PHI0 * (Pi / 180);
var RadLAM0 = LAM0 * (Pi / 180);
//Compute af0, bf0, e squared (e2), n and Et
var af0 = a * f0;
var bf0 = b * f0;
var e2 = (Math.pow(af0,2) - Math.pow(bf0,2)) / Math.pow(af0,2);
var n = (af0 - bf0) / (af0 + bf0);
var Et = East - e0;
//Compute initial value for latitude (PHI) in radians
var PHId = GT_Math.InitialLat(North, n0, af0, RadPHI0, n, bf0);
//Compute nu, rho and eta2 using value for PHId
var nu = af0 / (Math.sqrt(1 - (e2 * (Math.pow(Math.sin(PHId),2)))));
var rho = (nu * (1 - e2)) / (1 - (e2 * Math.pow(Math.sin(PHId),2)));
var eta2 = (nu / rho) - 1;
//Compute Longitude
var X = (Math.pow(Math.cos(PHId),-1)) / nu;
var XI = ((Math.pow(Math.cos(PHId),-1)) / (6 * Math.pow(nu,3))) * ((nu / rho) + (2 * (Math.pow(Math.tan(PHId),2))));
var XII = ((Math.pow(Math.cos(PHId),-1)) / (120 * Math.pow(nu,5))) * (5 + (28 * (Math.pow(Math.tan(PHId),2))) + (24 * (Math.pow(Math.tan(PHId),4))));
var XIIA = ((Math.pow(Math.cos(PHId),-1)) / (5040 * Math.pow(nu,7))) * (61 + (662 * (Math.pow(Math.tan(PHId),2))) + (1320 * (Math.pow(Math.tan(PHId),4))) + (720 * (Math.pow(Math.tan(PHId),6))));
var E_N_to_Long = (180 / Pi) * (RadLAM0 + (Et * X) - (Math.pow(Et,3) * XI) + (Math.pow(Et,5) * XII) - (Math.pow(Et,7) * XIIA));
return E_N_to_Long;
}
GT_Math.InitialLat = function(North, n0, afo, PHI0, n, bfo)
{
//Compute initial value for Latitude (PHI) IN RADIANS.
//Input: - _
//northing of point (North) and northing of false origin (n0) in meters; _
//semi major axis multiplied by central meridian scale factor (af0) in meters; _
//latitude of false origin (PHI0) IN RADIANS; _
//n (computed from a, b and f0) and _
//ellipsoid semi major axis multiplied by central meridian scale factor (bf0) in meters.
//REQUIRES THE "Marc" FUNCTION
//THIS FUNCTION IS CALLED BY THE "E_N_to_Lat", "E_N_to_Long" and "E_N_to_C" FUNCTIONS
//THIS FUNCTION IS ALSO USED ON IT'S OWN IN THE "Projection and Transformation Calculations.xls" SPREADSHEET
//First PHI value (PHI1)
var PHI1 = ((North - n0) / afo) + PHI0;
//Calculate M
var M = GT_Math.Marc(bfo, n, PHI0, PHI1);
//Calculate new PHI value (PHI2)
var PHI2 = ((North - n0 - M) / afo) + PHI1;
//Iterate to get final value for InitialLat
while (Math.abs(North - n0 - M) > 0.00001)
{
PHI2 = ((North - n0 - M) / afo) + PHI1;
M = GT_Math.Marc(bfo, n, PHI0, PHI2);
PHI1 = PHI2;
}
return PHI2;
}
GT_Math.Lat_Long_H_to_X = function(PHI, LAM, H, a, b)
{
// Convert geodetic coords lat (PHI), long (LAM) and height (H) to cartesian X coordinate.
// Input: - _
// Latitude (PHI)& Longitude (LAM) both in decimal degrees; _
// Ellipsoidal height (H) and ellipsoid axis dimensions (a & b) all in meters.
// Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI = PHI * (Pi / 180);
var RadLAM = LAM * (Pi / 180);
// Compute eccentricity squared and nu
var e2 = (Math.pow(a,2) - Math.pow(b,2)) / Math.pow(a,2);
var V = a / (Math.sqrt(1 - (e2 * ( Math.pow(Math.sin(RadPHI),2)))));
// Compute X
return (V + H) * (Math.cos(RadPHI)) * (Math.cos(RadLAM));
}
GT_Math.Lat_Long_H_to_Y =function(PHI, LAM, H, a, b)
{
// Convert geodetic coords lat (PHI), long (LAM) and height (H) to cartesian Y coordinate.
// Input: - _
// Latitude (PHI)& Longitude (LAM) both in decimal degrees; _
// Ellipsoidal height (H) and ellipsoid axis dimensions (a & b) all in meters.
// Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI = PHI * (Pi / 180);
var RadLAM = LAM * (Pi / 180);
// Compute eccentricity squared and nu
var e2 = (Math.pow(a,2) - Math.pow(b,2)) / Math.pow(a,2);
var V = a / (Math.sqrt(1 - (e2 * ( Math.pow(Math.sin(RadPHI),2))) ));
// Compute Y
return (V + H) * (Math.cos(RadPHI)) * (Math.sin(RadLAM));
}
GT_Math.Lat_H_to_Z =function(PHI, H, a, b)
{
// Convert geodetic coord components latitude (PHI) and height (H) to cartesian Z coordinate.
// Input: - _
// Latitude (PHI) decimal degrees; _
// Ellipsoidal height (H) and ellipsoid axis dimensions (a & b) all in meters.
// Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI = PHI * (Pi / 180);
// Compute eccentricity squared and nu
var e2 = (Math.pow(a,2) - Math.pow(b,2)) / Math.pow(a,2);
var V = a / (Math.sqrt(1 - (e2 * ( Math.pow(Math.sin(RadPHI),2)) )));
// Compute X
return ((V * (1 - e2)) + H) * (Math.sin(RadPHI));
}
GT_Math.Helmert_X =function(X,Y,Z,DX,Y_Rot,Z_Rot,s)
{
// (X, Y, Z, DX, Y_Rot, Z_Rot, s)
// Computed Helmert transformed X coordinate.
// Input: - _
// cartesian XYZ coords (X,Y,Z), X translation (DX) all in meters ; _
// Y and Z rotations in seconds of arc (Y_Rot, Z_Rot) and scale in ppm (s).
// Convert rotations to radians and ppm scale to a factor
var Pi = 3.14159265358979;
var sfactor = s * 0.000001;
var RadY_Rot = (Y_Rot / 3600) * (Pi / 180);
var RadZ_Rot = (Z_Rot / 3600) * (Pi / 180);
//Compute transformed X coord
return (X + (X * sfactor) - (Y * RadZ_Rot) + (Z * RadY_Rot) + DX);
}
GT_Math.Helmert_Y =function(X,Y,Z,DY,X_Rot,Z_Rot,s)
{
// (X, Y, Z, DY, X_Rot, Z_Rot, s)
// Computed Helmert transformed Y coordinate.
// Input: - _
// cartesian XYZ coords (X,Y,Z), Y translation (DY) all in meters ; _
// X and Z rotations in seconds of arc (X_Rot, Z_Rot) and scale in ppm (s).
// Convert rotations to radians and ppm scale to a factor
var Pi = 3.14159265358979;
var sfactor = s * 0.000001;
var RadX_Rot = (X_Rot / 3600) * (Pi / 180);
var RadZ_Rot = (Z_Rot / 3600) * (Pi / 180);
// Compute transformed Y coord
return (X * RadZ_Rot) + Y + (Y * sfactor) - (Z * RadX_Rot) + DY;
}
GT_Math.Helmert_Z =function(X, Y, Z, DZ, X_Rot, Y_Rot, s)
{
// (X, Y, Z, DZ, X_Rot, Y_Rot, s)
// Computed Helmert transformed Z coordinate.
// Input: - _
// cartesian XYZ coords (X,Y,Z), Z translation (DZ) all in meters ; _
// X and Y rotations in seconds of arc (X_Rot, Y_Rot) and scale in ppm (s).
//
// Convert rotations to radians and ppm scale to a factor
var Pi = 3.14159265358979;
var sfactor = s * 0.000001;
var RadX_Rot = (X_Rot / 3600) * (Pi / 180);
var RadY_Rot = (Y_Rot / 3600) * (Pi / 180);
// Compute transformed Z coord
return (-1 * X * RadY_Rot) + (Y * RadX_Rot) + Z + (Z * sfactor) + DZ;
}
GT_Math.XYZ_to_Lat =function(X, Y, Z, a, b)
{
// Convert XYZ to Latitude (PHI) in Dec Degrees.
// Input: - _
// XYZ cartesian coords (X,Y,Z) and ellipsoid axis dimensions (a & b), all in meters.
// THIS FUNCTION REQUIRES THE "Iterate_XYZ_to_Lat" FUNCTION
// THIS FUNCTION IS CALLED BY THE "XYZ_to_H" FUNCTION
var RootXYSqr = Math.sqrt(Math.pow(X,2) + Math.pow(Y,2));
var e2 = (Math.pow(a,2) - Math.pow(b,2)) / Math.pow(a,2);
var PHI1 = Math.atan2(Z , (RootXYSqr * (1 - e2)) );
var PHI = GT_Math.Iterate_XYZ_to_Lat(a, e2, PHI1, Z, RootXYSqr);
var Pi = 3.14159265358979;
return PHI * (180 / Pi);
}
GT_Math.Iterate_XYZ_to_Lat =function(a, e2, PHI1, Z, RootXYSqr)
{
// Iteratively computes Latitude (PHI).
// Input: - _
// ellipsoid semi major axis (a) in meters; _
// eta squared (e2); _
// estimated value for latitude (PHI1) in radians; _
// cartesian Z coordinate (Z) in meters; _
// RootXYSqr computed from X & Y in meters.
// THIS FUNCTION IS CALLED BY THE "XYZ_to_PHI" FUNCTION
// THIS FUNCTION IS ALSO USED ON IT'S OWN IN THE _
// "Projection and Transformation Calculations.xls" SPREADSHEET
var V = a / (Math.sqrt(1 - (e2 * Math.pow(Math.sin(PHI1),2))));
var PHI2 = Math.atan2((Z + (e2 * V * (Math.sin(PHI1)))) , RootXYSqr);
while (Math.abs(PHI1 - PHI2) > 0.000000001) {
PHI1 = PHI2;
V = a / (Math.sqrt(1 - (e2 * Math.pow(Math.sin(PHI1),2))));
PHI2 = Math.atan2((Z + (e2 * V * (Math.sin(PHI1)))) , RootXYSqr);
}
return PHI2;
}
GT_Math.XYZ_to_Long =function (X, Y)
{
// Convert XYZ to Longitude (LAM) in Dec Degrees.
// Input: - _
// X and Y cartesian coords in meters.
var Pi = 3.14159265358979;
return Math.atan2(Y , X) * (180 / Pi);
}
GT_Math.Marc =function (bf0, n, PHI0, PHI)
{
//Compute meridional arc.
//Input: - _
// ellipsoid semi major axis multiplied by central meridian scale factor (bf0) in meters; _
// n (computed from a, b and f0); _
// lat of false origin (PHI0) and initial or final latitude of point (PHI) IN RADIANS.
//THIS FUNCTION IS CALLED BY THE - _
// "Lat_Long_to_North" and "InitialLat" FUNCTIONS
// THIS FUNCTION IS ALSO USED ON IT'S OWN IN THE "Projection and Transformation Calculations.xls" SPREADSHEET
return bf0 * (((1 + n + ((5 / 4) * Math.pow(n,2)) + ((5 / 4) * Math.pow(n,3))) * (PHI - PHI0)) - (((3 * n) + (3 * Math.pow(n,2)) + ((21 / 8) * Math.pow(n,3))) * (Math.sin(PHI - PHI0)) * (Math.cos(PHI + PHI0))) + ((((15 / 8
) * Math.pow(n,2)) + ((15 / 8) * Math.pow(n,3))) * (Math.sin(2 * (PHI - PHI0))) * (Math.cos(2 * (PHI + PHI0)))) - (((35 / 24) * Math.pow(n,3)) * (Math.sin(3 * (PHI - PHI0))) * (Math.cos(3 * (PHI + PHI0)))));
}
GT_Math.Lat_Long_to_East =function (PHI, LAM, a, b, e0, f0, PHI0, LAM0)
{
//Project Latitude and longitude to Transverse Mercator eastings.
//Input: - _
// Latitude (PHI) and Longitude (LAM) in decimal degrees; _
// ellipsoid axis dimensions (a & b) in meters; _
// eastings of false origin (e0) in meters; _
// central meridian scale factor (f0); _
// latitude (PHI0) and longitude (LAM0) of false origin in decimal degrees.
// Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI = PHI * (Pi / 180);
var RadLAM = LAM * (Pi / 180);
var RadPHI0 = PHI0 * (Pi / 180);
var RadLAM0 = LAM0 * (Pi / 180);
var af0 = a * f0;
var bf0 = b * f0;
var e2 = (Math.pow(af0,2) - Math.pow(bf0,2)) / Math.pow(af0,2);
var n = (af0 - bf0) / (af0 + bf0);
var nu = af0 / (Math.sqrt(1 - (e2 * Math.pow(Math.sin(RadPHI),2) )));
var rho = (nu * (1 - e2)) / (1 - (e2 * Math.pow(Math.sin(RadPHI),2) ));
var eta2 = (nu / rho) - 1;
var p = RadLAM - RadLAM0;
var IV = nu * (Math.cos(RadPHI));
var V = (nu / 6) * ( Math.pow(Math.cos(RadPHI),3)) * ((nu / rho) - (Math.pow(Math.tan(RadPHI),2)));
var VI = (nu / 120) * (Math.pow(Math.cos(RadPHI),5)) * (5 - (18 * (Math.pow(Math.tan(RadPHI),2))) + (Math.pow(Math.tan(RadPHI),4)) + (14 * eta2) - (58 * (Math.pow(Math.tan(RadPHI),2)) * eta2));
return e0 + (p * IV) + (Math.pow(p,3) * V) + (Math.pow(p,5) * VI);
}
GT_Math.Lat_Long_to_North =function (PHI, LAM, a, b, e0, n0, f0, PHI0, LAM0)
{
// Project Latitude and longitude to Transverse Mercator northings
// Input: - _
// Latitude (PHI) and Longitude (LAM) in decimal degrees; _
// ellipsoid axis dimensions (a & b) in meters; _
// eastings (e0) and northings (n0) of false origin in meters; _
// central meridian scale factor (f0); _
// latitude (PHI0) and longitude (LAM0) of false origin in decimal degrees.
// REQUIRES THE "Marc" FUNCTION
// Convert angle measures to radians
var Pi = 3.14159265358979;
var RadPHI = PHI * (Pi / 180);
var RadLAM = LAM * (Pi / 180);
var RadPHI0 = PHI0 * (Pi / 180);
var RadLAM0 = LAM0 * (Pi / 180);
var af0 = a * f0;
var bf0 = b * f0;
var e2 = (Math.pow(af0,2) - Math.pow(bf0,2)) / Math.pow(af0,2);
var n = (af0 - bf0) / (af0 + bf0);
var nu = af0 / (Math.sqrt(1 - (e2 * Math.pow(Math.sin(RadPHI),2))));
var rho = (nu * (1 - e2)) / (1 - (e2 * Math.pow(Math.sin(RadPHI),2)));
var eta2 = (nu / rho) - 1;
var p = RadLAM - RadLAM0;
var M = GT_Math.Marc(bf0, n, RadPHI0, RadPHI);
var I = M + n0;
var II = (nu / 2) * (Math.sin(RadPHI)) * (Math.cos(RadPHI));
var III = ((nu / 24) * (Math.sin(RadPHI)) * (Math.pow(Math.cos(RadPHI),3))) * (5 - (Math.pow(Math.tan(RadPHI),2)) + (9 * eta2));
var IIIA = ((nu / 720) * (Math.sin(RadPHI)) * (Math.pow(Math.cos(RadPHI),5))) * (61 - (58 * (Math.pow(Math.tan(RadPHI),2))) + (Math.pow(Math.tan(RadPHI),4)));
return I + (Math.pow(p,2) * II) + (Math.pow(p,4) * III) + (Math.pow(p,6) * IIIA);
}
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