Questions tagged [wgs84]

WGS 84 is a geodetic coordinate system, commonly referred to as EPSG:4326.

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Shapely polygons crossing the antimeridian

Sample data Consider the following WKT Polygon, crossing the international dateline (antimeridian): POLYGON((176 49,-65 49,-65 11,176 11,176 49)) And the following points: POINT(-140 32) # ...
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408 views

How to get square metric pixels for a GeoTiff, whose pixel spacing is given in degree?

I have received a GeoTiff file, whose pixel spacing is provided in degree (e.g. +1° to the right, -1° down). Of course, this means that the actual, metric pixel spacing changes in relation to the ...
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376 views

QGIS 3D Globe Plugin Elevation Map Projection

I'm trying to get a map setup using the QGIS 'Globe Plugin'. I've been trying to use the UK Environment Agency LIDAR data as an elevation map. After a bit of puzzling this out I've found that the ...
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problem creating and editing features at extent edges

I'm in the process of creating a polyline feature layer of tectonic plates. I'm working with WGS-84 reference system, which means the extent is +-180 in lon, and +-90 in lat. In order to create the ...
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2k views

OSGB36 to WGS84 reprojection 'error'

First off, I am a recent convert to QGIS and am greatly impressed with its ease of use and speed compared with the ESRI products with which I am more familiar - my congratulations and thanks to its ...
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32 views

WGS84 to MSL and opposite

I am using Cesium to create point in a map. The point will be then flyable with a drone. I have the following problem, 1) The user set a point altitude to 20 meters in a 2D flat map. 2) The point ...
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42 views

Unknown coordinate system from web API

I'm trying to figure out (and eventually convert to WGS) projection system of coordinates I get from one web API service. As an example - lat, long = 71804125, 180232666 is a point in Cracow, Poland. ...
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75 views

Raster reprojection in QGIS leads to different results

I have a base ASTER 30m raster map from which contours have been extracted / reprojected to UTM using different processes in QGIS 2.14: ASTER (WGS84) > save raster as using Project CRS (UTM) > ...
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520 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 ...
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284 views

Auto-Sanitizing illegal PostGIS WGS84 (lat, lon) coordinates

I have just stumbled upon what seems to be a very curious behaviour by PostGIS. The XYZ point -117.0, 32.0, 0 in WGS84 (SRID 4326) is legal: items=> SELECT st_y(st_geomfromtext('POINT Z (-117.0 ...
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2k views

Returning distances in meters from Near (Analysis) tool of ArcGIS for Desktop?

I'm trying to write a python program that returns the distance from each point in a set to the nearest road. Specifically, I was looking for any points within 10 meters of the roads. Both sets of ...
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416 views

Height of the geoid in ECEF coordinates

I know that the relationship of geoid height N and ellipsoid height h to orthometric height H is defined by H = h - N, but what if I have some position in Earth-Centered-Earth-Fixed (ECEF) coordinates?...
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Projecting a Raster from WGS84 to planar Equal Area to Calculate Area: How to Select the Cell Size?

I have a broad question on how to calculate the 'correct' cell size for a raster when analyzing an area not at the equator. My goal is to project a land cover raster provided in GCS WGS84 to an equal ...
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189 views

is ellipse inside ellipse in WGS84 ellipsoid

My question is quite clear: Assume that there is an ellipse, namely EL1. Parameters of the ellipsoid are (focus11 [latitude, longitude], focus12[latitude, longitude], radius1). And a second ellipse, ...
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358 views

Projection discrepancy with GDAL (1.9) and proj4

I boiled the problem down to that Python example: import sys try: from osgeo import gdal from osgeo import osr except: import gdal import osr if __name__ == '__main__': version_num = int(gdal....
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34 views

Changing Map Coordinate System Changes in ArcGIS Pro Changes Azimuth

I am trying to create a label that will overlay a line in ArcGIS Pro, the layer is coming from a PostGIS database. The underlying materialized view for the label/symbol overlay is something like this: ...
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179 views

How to calculate OSM WGS84 Lat and Lon to meters in C++?

Summary I am converting OSM coordinates into X and Y values with accurate distances in meters between all points using c++. The calculations/code I am using is resulting in an incorrect ratio/scale ...
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1answer
120 views

Calculating minimum distance in meters of two polygons (defined in lat/long coordinates)?

I'm new to GIS and I'm a bit lost in the terms and concepts, so I'm not sure I'm asking a valid question, but I need to calculate the minimum distance (in meters) of two polygons which are defined in ...
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1answer
504 views

Converting NAD83 (epsg:4269) to WGS84 (epsg:4326) using pyproj

I'm trying to convert US census data (NAD83) to WGS84. I know the difference between the two is quite minor, but trying to apply the transformation using pyproj does not do anything. e.g.: from ...
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40 views

How to use coordinates search bar in QGIS?

When using coordinates search bar in QGIS, it sends me to a completely different location. The GPS coordinates style is 37.381096, 14.561191 and the project is set to EPSG: 3857 with OpenLayers ...
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34 views

Avoiding grids when transforming between SRS using ogr2ogr?

I'm trying to use ogr2ogr to transform from NAD27 (EPSG:4267) to WGS84 with my custom "towgs84" Bursa-Wolf parameters. However, I think the ogr2ogr uses grids which are part of the GDAL installation ...
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83 views

QGIS map wraparound in WGS84

I am learning QGIS. I'm working with the 'Natural_Earth_quick_start' data set from the tutorials. The WGS84 projection gives me the view I want. However, this looks like a sheet of paper, and on the ...
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77 views

Improving reprojection accuracy

Main question: how can I improve the accuracy of my reprojection? I am combining my dataset to a previous one, and I have chosen a different CRS: the previous one is in WGS 84 (EPSG:4326) and mine is ...
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185 views

Projecting Lambert WGS 84 using QGIS?

I am currently preparing raster layers in QGIS to be fed into MaxEnt to run a species distribution model. I downloaded climatic variables in ascii format from I downloaded from Adaptwest (https://...
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247 views

QGIS layer stretched

I try to work out a way to assemble the layers I have got in my QGIS project so that no layer appears to be stretched. original coordinate systems: vector layer: WGS 84 UTM Zone 34N raster layer: ...
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202 views

Convertion of Geotiff from EU-DEM EPSG:3035 - ETRS89 / ETRS-LAEA to WGS84

I have downloaded elevation data from EU-DEM My background is in software engineering and my GIS skills are limited. How can I convert the aforementioned geotiff to WGS84 format geotiff with lon/lat ...
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37 views

Error in projection or just a graphical error?

I've got a worldwide SRTM grid in WGS84 and want to reproject it to UTM coordinates. If I do so in parts of the world are strange tiles of the map (especially in Eurasia), which are not part of the ...
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42 views

Converting raster from WGS_1984_plate_carree to WGS_1984 in ArcGIS Desktop?

I am a beginner using ArcGIS and I downloaded a TIFF which is in WGS_1984_plate_carree coordinate system. This image covers all the world and in this coordinate system the extent goes from -180 (left)...
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107 views

How to create a csv with lat long coordinates from a WGS84 layer with Grass

This question seems trivial but I'm having trouble doing this simple task. I'm working on a WGS84 location in Grass 6.4 and I'm trying to convert a raster layer in a csv with lat long coordinates ...
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307 views

Converting from Eastings and Northings on British Ordnance Survey to WSG84

I am a software developer currently working on a project that relies heavily upon knowing if our position is within a defined region - specified as a polygon using a set of points to define a linear ...
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226 views

Spatial reference conflict: WGS84 or clrk66

For a raster dataset, trying my.raster@crs or proj4string(my.raster) in R gives the PROJ.4 string "+proj=longlat +ellps=clrk66 +no_defs". I downloaded the raster from SEDAC here - the World link, ...
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What WGS84 epoch date is used by Google Maps

I have some Nad83 data that I want to overlay on Google Maps. This article by ngs.noaa.gov explains translating from nad83 to wgs84 better than anything I have read. If I were to use a tool like the ...
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218 views

gdalinfo corner coordinates off file

When running gdalinfo on an SRTM file, I get the corner coordinates. However, when I attempt to get the elevation at those coordinates using gdallocationinfo -wgs84 file.hgt {corner coordinates} I get ...
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240 views

Transforming azimuthal to wgs projection using Python?

I want to plot a circle around a given lat/long with a certain radius on the Earth. The shapefile of the earth has WGS84 coordinate system. First, I projected the circle to azimuthal equidistant map ...
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928 views

Convert locations from ECEF NED (local coordinate system) to WGS 84 (global coordinate system)

I track relative positions to known fixed reference location (Lat/Lon/Alt on WGS 84). Which means Location_0 is the above reference location, and Location_i is something like (X,Y,Z) relative by ...
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219 views

a localised 2D coordinate system from GPS coordinates

I spend a few days reading about coordinate systems, map projections, datums, etc. Since I am new to gis, I am not confident I am doing this right. Problem at hand: I have a GPS device that gives ...
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Intersection of 4D Trajectory with 4D Polyeder (3D + time)

I have worldwide small polygons (lat/lon WGS84) for different heights (z-coordinate) for several timestamps (m). I want to store them in a PostgreSQL/PostGIS database as 4D objects (2D polygons + ...
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159 views

from/to ellipsode to/from cartesian conversion

i am trying to convert from/to ellipsoidal coordinates (lat,lng,alt) to/from cartesian(x,y,z) i wrote the below code to do the conversion, but given the initial values of the gpsLat and gpsLng i ...
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1k 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 ...
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265 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: the ...
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216 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 ...
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158 views

Inputting Longitude and Latitude in CSV from Geotagged, Photo Coordinates (WGS 84)

I am trying to take Geotagged picture coordinates and put them into a CSV file to display in QGIS as point values. Using Picasa, I can see that the picture coordinates are in the correct locations on ...
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238 views

How to choose a projection for area measurement on building to continental scales?

I have many geographical objects described as polylines, polygons, multipolygons. All objects are in WGS84. Object could be: a building, stadium, park, street, highway, city, state, even country and ...
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WGS84 to OSGB, using VB script

I have adapted someone else's VB code to convert lat long to OSGB for UK locations. In essence my code converts a Google API location returned from a text search, into Eastings and Northings that can ...
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1k views

Determine lat/lon intersection on earth from point in space along 3d line

I have a known point in space with a lat,lon,alt. It has a camera with a line of sight and a angle of field of view. I can take the central point and calculate each corner vector of the field of view, ...
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219 views

convert headerless flat binary files to tif

I have set of headerless flat binary files (those are out put files of TIMESAT software). I want to convert those to .tif format. I did it using ENVI. but it does not overlap with the original input ...
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269 views

Node.js transformation from NAD83 to WGS84

I've used the excellent npm shapefile library to import Canadian electoral districts into MongoDB. Here's a sample file: http://ftp2.cits.rncan.gc.ca/pub/geott/electoral/2011/fed308.2011.zip Is ...
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69 views

My map is little bit off

I am pretty new in GIS things and i have been learning how to use QGIS. Most of the maps are fine, but yesterday I went to GIS center at my University and I got the maps of my country that I will be ...
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403 views

How to determine the Geoid model used by GPS receiver?

I have the following NMEA output by Holux M-241 GPS receiver: $GPGGA,144014.000,2227.0987,N,11410.1382,E,2,6,1.67,32.6,M,-1.3,M,0000,0000*7B I know that WGS84 height is higher than geoid height 1.3 ...
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565 views

GeoTools: SimpleFeatureCollection to KML error CoordinateReferenceSystem

I want to export a SimpleFeatureCollection (Read from a MySQL DB) to a KML file, here is my code used to read the infos into the console: private void featureCollectionToKML(SimpleFeatureCollection ...