The coordinate system known as World Geodetic System 1984 (EPSG:4636)

learn more… | top users | synonyms

4
votes
1answer
15 views

WRF Spherical Earth to WGS 84

Weather Research Forcasting Model assumes a spherical earth model with a radius of 6370km. I'm looking to display the data onto the WGS-84 Ellipsoid model as that is the model my system uses for its ...
0
votes
0answers
35 views

Convert WGS84 coordinates to ECEF Cartasian (XYZ) coordinates using pyproj

I need to convert WGS84 to ECEF to map some points to a 3D sphere. I've trawled through the pyproj docs, but can't find specifics on the matter. Basically I want to input the WGS84 GPS lon/lat ...
2
votes
3answers
3k views

Transform from WGS84 to EPSG 3785 (google maps)

I am a Java Developer and I was given this coordinates from a database verbat_sistema_coordenadas verbatim_SRS datum verbat_longitud verbat_latitud UTM WGS84 ...
3
votes
1answer
34 views

Checking if two WGS84 lines intersect in JavaScript

I am trying to work out given two GeoJSON lines (WGS84), if they intersect (i.e. cross one another). Let me give some pseudocode to illustrate: // Providing Line 1 = lon1, lat1 and Line 2 = lon2, ...
1
vote
3answers
137 views

What is the Origin of WGS84 UTM 18N?

I was given an unprojected coordinate in the form of lat, lon and I am using pyproj to convert to projected coordinate as such: from pyproj import Proj # New Jersey lat = 40.704895 lon = -74.094994 ...
1
vote
1answer
54 views

projection (WGS84, UTM) issue

I have a question about projections. I have a hillshade raster with UTM 31N projection (I reprojected this from WGS 84). I also have a satellite image that I need to georeference. For georeferencing I ...
2
votes
0answers
35 views

Find gravity normal by ECEF or GPS coordinate of point

How to find gravity normal by ECEF or GPS coordinate of point? Is it the same as normal to elipsoid? Is this ordinary way to calculate normal to ellipse? I'm not quite sure which altitude is ...
6
votes
2answers
116 views

Is a Helmert transform necessary to convert between WGS84 and NAD83?

I've read things all over the internet which claim that NAD83 and WGS84 are effectively equivalent (with minor ellipsoid differences). However, if I do geodetic (WGS84) -> ECEF -> geodetic (NAD83) ...
2
votes
2answers
392 views

Making Fishnet that is specific size in square meters on ground?

I have a raster image in GCS WGS 1984. For sampling I want to take a grid of 500 m^2 in my area of interest and pick the centroid of this square. How do I make sure that the grid created with Fishnet ...
1
vote
3answers
61 views

Area units for output polygon in WGS 84 UTM Zone 32N using QGIS

I am calculating the area of my polygon and I have used WGS 84 UTM zone 32N to calculate the area (using geometry on the field calculator) of my polygon, and I obtained 745461 (without units). How ...
0
votes
1answer
758 views

Converting Lat/Lon to Pixel-XY on cropped map?

I have a GPX-Track containing LatLon coordinates based on WGS84. The track should be drawn on a cropped map, and for this, I need the pixel coordinates. The map tiles are from OSM I'm not quite sure ...
0
votes
0answers
28 views

Can I use a polygon envelope I get from JavaTopologySuite(.NET port) in an R-tree implementation? (wgs84 to spatial)

I'm using this implementation of https://github.com/enyim/RTree. I use the .NET port of JavaTopologySuite to create some polygons and then get their bounding rectangles. IPolygon p = ...
3
votes
1answer
2k views

How to convert (geodetic pose + cartesian offset) to geodetic position

I am in search of an algorithm to solve the first/direct geodetic problem precisely in 3D. The input is: a geodetic (not geocentric) position (WGS84, height is above the WGS84 reference ellipsoid) ...
1
vote
1answer
41 views

JTS polygon intersection calc on a geoid

I am using JTS to compute intersections between polygons with WGS84 lat/lon coordinates. I am not converting coordinates to anything 2D based, just reading in POLYGON(lat lon, lat lon) and doing ...
16
votes
3answers
11k views

How do you compute the earth's radius at a given geodetic latitude?

(I see there is an equation on wikipedia that does exactly what I am asking but there is no references. I have no way of confirming the validity of this equation!) I already understand the difference ...
2
votes
1answer
44 views

Relation between Geoidal separation and antenna altitude in GGA sentence?

I have searched about definitions and relations about geoidal separation and antenna altitude reported in GGA sentence. The more I read the more I am confused.So in a simple manner can anyone explain ...
5
votes
4answers
8k views

What is the projection of WGS84 in GIS software?

WGS84 is a reference ellipsoid that determines coordinates of every point on Earth using latitude, longitude and height about the its surface. This ellipsoid is often used as a base to make maps. ...
1
vote
2answers
181 views

Why do MGI and WGS 84 data not line up in ArcGIS for Desktop?

When i reproject raster from MGI 6 zone to the WGS84 it makes a mistake (it is moved for 380 m )See example below: I know that the problem is in MGI 6 projection (it is not accurate),but I do not ...
3
votes
2answers
593 views

How do I convert EPSG:26986 coordinate pairs to EPSG:4326 from the MassGIS web service, the Linux command-line, or PHP?

I'm a GIS newbie, normally a PHP web applications developer. I am trying to map all boundaries of the MA state representative districts. So I just need to convert polygon coordinates from the ...
0
votes
0answers
26 views

Triangulation of Cell Towers using MSQL Server Spatial

I need to triangulate a GSM Device by using known cell towers locations and GSM readings. All Data is in a MS SQL Server as Geometry Types. herewith an example of the data : here is also a SQL ...
-1
votes
1answer
30 views

Converting UTM55 to WGS84 in ArcMap? [closed]

I've got a raster in UTM55 over Australia and I would like to convert it to WGS84. Any idea how to do it ? The problem starts when ArcMap recognize it as 'Geo-Reference' only and not as UTM55, so I ...
2
votes
2answers
152 views

Projecting shapefile with unknown CRS to WGS84 using QGIS?

I've tried setting QGIS to on the fly, changing the layer settings, nothing. I'm at a lost cause. Although I am not a GIS professional. ...
0
votes
2answers
170 views

MODIS-Sphere to WGS84 coordinate system in ArcGIS [duplicate]

I want to overlay two global raster datasets on land use which use different coordinate systems (MODIS-Sphere & WGS84) using ArcGIS Desktop. There seems to be no direct transformation option from ...
1
vote
1answer
54 views

Converting x,y on mercator to WGS84 latitude and longitude

How do I convert a particular point on a Mercator map (points in a Mercator map svg) to WGS84 coordinates? Is it simply a direct translation of the x,y values, using a multiplier which matches the map ...
2
votes
3answers
173 views

Mis-aligned shapefiles in QGIS?

I'm a beginner at QGIS and I'm having trouble aligning my shapefiles. I have two datasets: one originally in WGS84 (lat/long) and another in Corrego Alegre/UTM zone 24S. I need to convert the second ...
3
votes
1answer
74 views

Is re-projection needed from SRID 4326 (WGS 84) to 4269 (NAD 83)SRID

I have US census data against state boundaries stored as SRID 4269, in an MSSQL DB. The input data used for calculations against that dataset is stored as SRID 4326. As far as I can infer from the ...
1
vote
1answer
28 views

How to calculate areas for data that covers the whole of Australia [duplicate]

I have a polygon shapefile showing mining areas across all of Australia. I want to calculate the area for each of the polygons however they have been provided in a Geographic Coordinate System ...
0
votes
1answer
100 views

Transforming from EPSG:2154 to EPSG:3857 using ProjNet4GeoApi/Proj.net, C#

I don't have much experience with GIS. Here's are my projections defintion: private Dictionary<CoordinateSystemStrings, string> CoordinateSystemStringDictionary = new ...
0
votes
1answer
183 views

Transforming coordinates from WGS84 to Gauss-Krüger 5

GPS coordinates in the format of WGS84 are quite common. I need to transform them into Gauss-Krüger coordinates but I have no idea how to do that. The only things I know are that it is not easy and I ...
1
vote
0answers
61 views

GeoTools: Lambert72 to WGS84

I am trying to convert coordinates (and polygons from com.vividsolutions.jts.geom) in Lambert72 (EPSG:31370) to WGS84 (or the other way around). I'm using the org.geotools.referencing CRS and ...
1
vote
1answer
1k views

Convert from ITM ref to GPS ref?

How can I convert from ITM ref (Israel new map) to GPS ref and from GPS ref to ITM ref? I need any C# sample code or formula for this. For example: 32.086156,34.769239 = 178364,665948 Or : ...
0
votes
1answer
30 views

What is most accurate Spatial reference system for calculate Area entire world [duplicate]

I want to know what Spatial reference system is most accurate to calculate area? I want to use it for entire world (-180,+180,-90,+90 area in WGS84 system) I have every thing ok I only need to ...
4
votes
1answer
220 views

On python, how to generate an array of coordinates between two points

Perhaps I'm looking to a solved question, but while searching I didn't find any solution. I need to build a matrix of lat, lon values, based on two points, and a sampling rate (distance between ...
10
votes
3answers
2k views

What causes the GPS offset/shift in China?

I've spent close to two full days trying to understand the nature of the infamous GPS shift in China. After sifting through the noise, two recurring symptoms are that: GPS coordinates (WGS-84) plot ...
1
vote
0answers
57 views

WGS84 Lon/Lat from pixel x/y in a georeference image

I'm quite a newbie in GIS. I need to compute (without using any existing lib/tool) the longitude & latitude (WGS84) corresponding to the a pixel, inside a (georeferenced) map image. I know: ...
19
votes
5answers
12k views

Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { ...
4
votes
2answers
898 views

Geographic Transformations in Alaska Between NAD83 and WGS84

I have done a ton of research on the most accurate transformation to use in mainland Alaska to convert between the NAD83 and WGS84 datums, but I just can't seem to find a definitive answer. ArcMap ...
3
votes
1answer
26 views

Equation or approximation of short distance path on Mercator

I use osm map in my project and I want to draw shortest line between two point like this: How do they draw this path? Give me please a clue )
2
votes
3answers
148 views

What is the altitude difference between WGS84 and NAD27 Zone II?

I have a point cloud in a piece of software and have exported the point in both WGS84 and NAD27 State Plane California Zone II (in US survey feet). The WGS data looks like this, with elevation in ...
2
votes
1answer
63 views

How to export a CSV with lat lon WKT from a layer which is not in WGS84?

I want to extract a csv with lat and lon coordinates so I select -- Geometry AS_WKT but when the csv is created I see this LINESTRING (277054.55782319931 198725.03588318737,277052.43701817648 ...
2
votes
1answer
361 views

Conflicting WGS84 coordinates between Trimble and Garmin GPS receivers

I am a contractor at a government facility in Nevada. We have our own in-house survey department who, for a number of reasons, still uses NAD27 State Plane Coordinates (Nevada Central Zone 2702) in ...
4
votes
2answers
6k views

How are EGM96 and WGS84 related to each other?

As far as I understand the EGM96 defines the Geoid, where as the WGS84 Standard defines the Ellipsoid. Is the ellipsoid defined in the WGS84 standard defined in a way to maximize the congruency with ...
3
votes
3answers
1k views

Proper gdaltransform syntax to transform a list of coordinates?

this is probably a very simple question, but I'm very new to GIS so I just need one last nudge. I've got a sense of the Linux utility gdaltransform and I am feeding it coordinate pairs in ...
0
votes
0answers
100 views

ArcGIS/ ArcPy - XY coordinates of feature class does not match calculated geometry XY

Tested on: different workstations, different Windows versions; ArcGIS Desktop 10.3, different license levels Background: I use the Google Maps DistanceMatrix to calculate drive times between two ...
4
votes
1answer
219 views

Should geometries be drawn using rhumb-line or great-circle paths?

I work with WGS-84 coordinates and, most of the time, my map display (luciadmap) is in Mercator projection. My client is surprised to see that, for a rectangular geometry: the line between the 2 ...
3
votes
1answer
146 views

Averaging Cartesian ECEF coordinates then converting to WGS84 without latitude drift

Preface: I'm unsure if GIS or math is the correct community for this question. I have a set of 9 WGS84 latitude/longitude (degree) pairs for which I need to find the weighted average of. To prevent ...
3
votes
1answer
188 views

How do I figure out the length of polyline features in a feature class with a WGS 1984 coordinate system?

I'm trying to figure out lengths of polyline features in a feature class with a WGS 1984 coordinate system. Here's code to list lengths: >>> import arcpy >>> inFc = ...
2
votes
0answers
78 views

Converting from flat earth to WGS84 with python

I'm looking to move from basic 2d Cartesian coordinate system into WGS84. I know my starting coordinates, however all intermediate points are x/y/z points. of an origin 0,0,0 . Mathlab has a ...
1
vote
1answer
158 views

Autocad DXF to Qgis and exporting to KML for viewing in Google Maps

/ Background: I have a DWG trace made in AutoCad using Gauss-Kruger coordinate system ( a CRS used in Slovenia ). I'm using AutoDesk Map 3D to transform the coordinate system to WGS84.PseudoMercator ...
2
votes
1answer
283 views

Converting Lambert Conformal Conic (LCC) to UTM

I have two numpy meshgrids (X, Y both 2D) in Lambert Conformal conic with the following information: I'd like to directly (or indirectly if not possible) project them to UTM. I have both pyproj and ...