|
Download the Eye4Software GPS Toolkit fully functional 30 day trial version for free |
|
Download Eye4Software GPS Toolkit Manual |
|
Browse through the Eye4Software GPS Toolkit manual |
The stereographic projection, in geometry, is a particular mapping (function) that projects a sphere onto a plane. The projection is defined on the entire sphere, except at one point — the projection point. Where it is defined, the mapping is smooth and bijective. It is conformal, meaning that it preserves angles. It is neither isometric nor area-preserving: that is, it preserves neither distances nor the areas of figures.
To convert Oblique Stereographic coordinates, the following parameters have to be set:
The following code sample (VBScript) shows how to use the Oblique Stereographic Projection from the Eye4Software GPS Toolkit:
' demo_stereographic.vbs
'
' This demo translates lat/lon coordinates (WGS84) to RDNAP coordinates (Amersfoort) using
' stereographic projection
'
' This demo specifies a map grid based on the Stereographic projection, by setting all geodetic parameters.
'
' If you want to convert using one of the 4000 grids that are included in the component,
' you should have a look at the demo_gridsimple.vbs demo (recommended for users with less or no experience in geodesy).
Option Explicit
Dim objDatumSrc, objDatumDst, objGridSrc, objGridDst, objProjection, objConstants
Set objDatumSrc = CreateObject ( "Eye4Software.GpsDatumParameters" )
Set objDatumDst = CreateObject ( "Eye4Software.GpsDatumParameters" )
Set objGridSrc = CreateObject ( "Eye4Software.GpsGridParameters" )
Set objGridDst = CreateObject ( "Eye4Software.GpsGridParameters" )
Set objProjection = CreateObject ( "Eye4Software.GpsProjection" )
Set objConstants = CreateObject ( "Eye4Software.GpsConstants" )
WScript.Echo "Eye4Software GPS Toolkit " & objProjection.Version & " - Stereographic Projection Demo"
WScript.Echo
' // Start of parameters part //
' Set Source Datum: WGS84
objDatumSrc.Axis = 6378137.000
objDatumSrc.Flattening = 298.257223563
' Set Source GridL: Latitude/Longitude
objGridSrc.Projection = 0
objGridSrc.Datum = objDatumSrc
' Set destination datum: Amersfoort
objDatumDst.Axis = 6377397.155
objDatumDst.Flattening = 299.1528183
objDatumDst.TranslationX = 539.16
objDatumDst.TranslationY = 26.15
objDatumDst.TranslationZ = 465.89
objDatumDst.RotationX = -1.304
objDatumDst.RotationY = -0.103
objDatumDst.RotationZ = -1.145
objDatumDst.ScaleFactor = 4.0772
' Set destination grid: RDNAP
objGridDst.Projection = objConstants.GPS_PROJECTION_STEREOGRAPHIC
objGridDst.Datum = objDatumDst
objGridDst.FalseNorthing = 463000.00
objGridDst.FalseEasting = 155000.00
objGridDst.OriginLatitude = 52.156161
objGridDst.OriginLongitude = 5.387639
objGridDst.ScaleFactor = 0.999908
' Set Source coordinates
objProjection.Latitude = 51.900000
objProjection.Longitude = 4.400000
' // End of parameters part //
' Perform the transformation
WScript.Echo "Convert from Latitude / Longitude to RDNAP using stereographic projection"
WScript.Echo
WScript.Echo "Latitude = " & objProjection.Latitude
WScript.Echo "Longitude = " & objProjection.Longitude
WScript.Echo
objProjection.TransformGrid objGridSrc, objGridDst
' Return the result
WScript.Echo "Result: " & objProjection.LastError & " (" & objProjection.LastErrorDescription & ")"
WScript.Echo
If ( objProjection.LastError = 0 ) Then
WScript.Echo "Northing = " & objProjection.Northing
WScript.Echo "Easting = " & objProjection.Easting
End If
WScript.Echo "Ready."