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Questions tagged [wgs84]

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

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634 views

Convert NAD27 to WGS84 with programming function like PHP

I am looking for a programming function that can convert NAD27 coordinates to WGS84. I know QGIS could do the conversion, but I need a function for my purposes.
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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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2answers
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Using pyproj and Mercator: x_0=0 and y_0=0?

I'm having a hard time figuring out how to project correctly from a Mercator projection to LAT/Lon. Basically, I have a netCDF file with the following variables: LON0 = 42.0 => reference longitude ...
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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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1answer
120 views

Why is my coordinate notation different?

I was working on a project in WGS84, and I was continually adding layers to it. As I was rendering in print composer and enabled grid-coordinates, I noticed that my coordinates were different. It's ...
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2answers
491 views

Transforming data from GCS Krasovsky to GCS WGS84?

I am having trouble transforming data from GCS_Krasovsky_1940 to GCS_WGS_1984 in ArcGIS 10.4.1. I'm using the Project tool, but the geographic transformation parameter is left empty and I would expect ...
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1answer
292 views

What are the corner coordinates of a global map in meters?

We all know that the corner coordinates of a global map in degrees are -180, 90; -180, -90; 180, 90; and 180, -90 (top left; bottom left; top right; bottom right). So what are the corresponding ...
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1answer
505 views

Resample SMOS dataset using cKDTree and Bilinear interpolation

I have three datasets now. One is SMOS level3 soil moisture dataset which is in EASE grid 2.0 ~25km cylindrical projection. (EPSG: 6933). TRMM precipitation dataset which is in 0.25 degree. SMAP soil ...
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1answer
804 views

Converting UTM coordinates to WGS 84

I know the coordinates below are in UTM 36N (due to the EPSG code), and I can convert them with several websites online to wgs 84 and see them in Google Maps. However, been helplessly looking the ...
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1answer
305 views

Creating a Line at a Length and Angle in WGS84 - Arcobjects

I need to draw a line at desired length(around 10-20 Km length) and a user entered angle. The map/data uses WGS84 coordinate system. So the measurement is geodesic. Here are the methods that I tried. ...
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2answers
885 views

projection from epsg:4326 to epsg:4258

I'm looking for projection functions to convert coordinates in 4326 to coordinates in 4258 and viceversa. Any suggestions?
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1answer
771 views

Convert Ordnance Survery (GB) Easting/Northing data to WGS84 lat/long

This is my first venture into GIS datasets. I've decided to start a little project which will eventually hook into the Google Maps api to overlay/plot/pin from data in my database. I've started ...
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1answer
477 views

Using lat/long NAD83 in XYtool in Arcgis

I have loaded a raster map that uses WGS 84. I want to locate stations/points on this map by using lat/long coordinated from an online map that uses NAD83. Can I just copy and paste the lat/long ...
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2answers
107 views

preparing GPS coordinates for processing in gis

I'm currently working on a masters in archaeology, using QGIS to examine some palaeolithic sites. I created a database with the site coordinates, which I collected from looking at bibliographies of ...
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1answer
218 views

Differences in the longitude and latitude between a LiDAR DSM and an optical image

I've downloaded the UK's LiDAR elevation data (see below) in laz format for a specific region (Tewkesbury) from: http://environment.data.gov.uk/ds/survey#/download From that, a DSM (Digital Surface ...
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1answer
3k views

How much error should occur when using WGS84 to ECEF coordinates?

The method is not recommended for distances larger than 4km. I am getting reasonable accuracy in terms of the east and north bearings, but for the up direction I am getting error upwards of 1km for ...
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1answer
248 views

Where to get world-map images for use in webglearth

I am using webglearth for a 3D earth globe. I already bought MapTiler, from the same makers. Now I am struggling with finding different world-map-images with the right projection. I need either WGS ...
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1answer
872 views

KD-Tree implementation with lat/lon coordinates

I have implemented a KD-Tree that stores coordinates (latitude, longitude). I have also implemented a Nearest Neighbor search algorithm using the Haversine distance. Will I get correct results (same ...
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2answers
774 views

Conversion from WGS84 to UTM NAD83

If all my data is in UTM NAD83 Zone 10 and I get new data in GCS WGS 1984 do I have to reproject the WGS data to UTM NAD83 Zone 10 for it to align correctly or can I just bring it into an mxd that is ...
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1answer
617 views

Converting a NAD27 Lambert Conformal Conic custom projection to WGS84 using QGIS

I am trying to convert some points from NAD27 Lambert Conformal Conic (custom projection) to WGS84 using QGIS 2.8.9. I am using the datum transformation parameters for El Salvador published here: http:...
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2answers
743 views

Coordinate System Mismatch in QGIS?

I understand that coordinate system mismatches between layers is a relatively common problem. Nevertheless, exploring other posts hasn't helped me understand my issue. In short, I have a DEM raster ...
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1answer
311 views

Reprojecting: trouble converting MapInfo data to shapefiles in QGIS

I was given a dataset generated in MapInfo. I need to use these files in QGIS, so I imported the .TAB files and saved them as ESRI shapefiles. I then realised the original dataset uses a custom "user ...
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1answer
860 views

Negative coordinates for WGS84 system are invisible - ArcGIS 10.2

I have a csv file with point coordinates in GCS_WGS_1984 geographic system. I've imported it to ArcMap as a XY file however negative values for West hemisphere are not visible (but ALL records are in ...
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1answer
424 views

Converting GeoTiff to UTM in QGIS is slow?

I am trying to convert a Geotiff from WGS84 to UTM17. In QGIS, there seems to be a super easy way to do this: First, I input my tiff by clicking add raster layer. This works successfully, as I can ...
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1answer
827 views

How to divide line into three equal parts?

I have a problem with line division. I'm writing a program in JS/C++ generating KML files. I was trying to divide a line using my own function (which is correct on cartesian space): var part1Lon ...
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1answer
3k views

Guessing unknown projection in Malaysia

I have a database of northings and eastings of boundary markers of land parcels that are in a form that I cannot pin on any format. I would like to perform some conversions on them so that they can be ...
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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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1answer
147 views

convert REGCAN95 coordinates to OpenStreetMap coordinates (WGS84-Form in lat/long)

I have some coordinates in datum REGCAN95, and I want to know how to convert them to something usable in OpenStreetMap. I have found that REGCAN95 uses the EPSG codes as follows: 4082 REGCAN95 for ...
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1answer
193 views

Given WGS84 bounding box, is there service that returns most accurate projection to use?

I'd like to find a service to convert lat/lon in WGS84 to an arbitrary coordinate system in metric that will be the most accurate for my bounding box. Does something like this exist? For instance, ...
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1answer
231 views

confused about distances on the wgs-84 ellipsoid

As far as I understand given a certain latitude the length of a degree of longitude is constant. So using any distance calculator (I use Mathematica here) this equals: (circumference of the earth) ...
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1answer
829 views

Create grid from raster with equal size squares

I have a raster of the globe with coordinate system WGS_84. I want to create a grid on that raster where every square has the same size. When I use the Create Fishnet tool the size of squares get ...
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2answers
1k views

Is WGS 84 datum, coordinate reference system, or both?

The background to this question is in Understanding difference between Coordinate System and Projection? There @mdsumner commented: WGS84 is not a cs, it's a datum. On a couple of places online I ...
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Polygons across international dateline [-180..+180 longitude]

I'm trying to generate polygons for satellite orbital swaths. So far I have a method to generate two lines which represent the edge of each swath in [lat,long]. Some of the swath's cross the ...
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1answer
160 views

Why does QGIS do an unintended datum shift to WGS84 in the map canvas

I'm a new QGIS user running 2.12 Lyon. I've encountered an issue with map canvas units and an unexpected and transparent datum transformation to WGS84. I need help figuring out if I've missed ...
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1answer
510 views

Finding the origin in .laz file with LAStools

I obtained a .laz file, which I used lasinfo and las2txt to view the records. Scale Factor X Y Z: 0.00100000000000 0.00100000000000 0.00100000000000 Offset X Y Z: 22717....
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1answer
2k views

Failed to export vector file from OGR?

I use to transform data points from UTM (WGS84) to WGS84 EPSG:4326. Basically from UTM to Geographic coordinate system both in (WGS84). I tried to do it again but an error message appears. ...
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1answer
64 views

which projection are best for large continents [closed]

which projections are best for large continents and mid-latitudes
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1answer
1k views

How to transform 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 ...
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3answers
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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 ...
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1answer
577 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, ...
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1answer
222 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 ...
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2answers
1k 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 GPS ...
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2answers
799 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) ...
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3answers
3k 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 ...
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1answer
397 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 ...
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3answers
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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 ...
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1answer
475 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 ...
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1answer
3k 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 ...
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1answer
5k 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 ...
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1answer
488 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 (GDA_94)...