Questions tagged [wgs84]

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

Filter by
Sorted by
Tagged with
6
votes
2answers
1k views

Why does WGS84 refer to so many different things?

Sounds like a stupid question, but I've been struggling with this. Here's a diagram of the structure for EPSG 4326 - the geographic CRS known as WGS 84. Here we have WGS 84 (a CRS), World ...
3
votes
1answer
414 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 ...
2
votes
2answers
657 views

Georeferencer QGIS not working?

I am trying to georeference a .png file. After inserting all the data I get the following error "Transform Failed: Failed to compute GCP transform: Transform is not solvable." What can be the ...
4
votes
1answer
378 views

Converting long, lat to tile of NASA GIBS - WGS 84 / Lat-lon / Geographic (EPSG:4326)?

I'm following GIBS API for Developers and I need to convert long, lat of POI to col and row of tile for given zoom. For example to get right tile in endpoint like: https://gibs.earthdata.nasa.gov/...
1
vote
1answer
153 views

Geographic Transformation in Alaska Between NAD83 (NSRS 2007) and WGS84

This is a related question to this one asked ~3 years ago: Geographic Transformations in Alaska Between NAD83 and WGS84 We are currently on ArcGIS Desktop 10.4.1 What is the best geographic ...
1
vote
1answer
118 views

Calculating imprecision introduced by using WGS 84 coordinates as x,y in raster?

I have several coordinates provided in WGS 84 which I need to rasterize. For that purpose I simply interpret the lat,lon coordinates as x,y coordinates and I apply some scaling. So e.g. anything in ...
2
votes
1answer
1k views

Why does Pyproj fail converting lon lat alt to ECEF?

I'm trying to convert a WGS84 lon, lat and alt to ECEF and Pyproj is giving me really weird results. My code is simply: lon, lat, alt = 49.74761271, -113.2179781, 0 ecef = pyproj.Proj(proj='geocent', ...
1
vote
0answers
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 ...
1
vote
0answers
1k views

WGS84 with elevation z [closed]

I need to define a data structure which for convenience reasons for users using my software should be related to WGS84 - if possible. So that it makes it easy for users to use my software, convert ...
2
votes
3answers
1k views

Performing QGIS Datum Transformation from WGS 1984 to NAD 1983?

Is there a way to transform a shapefile's datum from WGS 1984 to NAD 1983 in QGIS 2.18.0? In the picture I have attached, the green dots are points that were collected in the field using a Trimble ...
1
vote
1answer
135 views

Calculating distance between coordinates from point to a box?

I have two different WGS84 coordinates, A and B. A is just a (lat,lon,z) point and B is a (lat,lon,z) point inside the center of a box with the dimension height, width, depth (in meters). I need to ...
3
votes
1answer
209 views

Converting from Sweref99tm to WGS84

I have a lot of coordinates I want to convert from Sweref99tm to WGS84 for display on google maps. I'm using gdal installed on my laptop: $ echo "6782384 599140" | gdaltransform -s_srs EPSG:3006 -...
1
vote
2answers
6k views

Converting WGS84 to ECEF in Python?

I am trying to convert some coordinates geodetic coordinates (WGS84) to ECEF. I've tried my own implementation in Python and using pyproj and am getting difference results. Could someone please help ...
3
votes
2answers
533 views

When is data created in datums other than WGS84?

I'm trying to understand why we need datums other than WGS84. Since GPS coordinates are relative to the WGS84 ellipsoid what is the advantage of having other datums like for example NAD83. I ...
3
votes
1answer
2k views

Transforming UTM layer to WGS using QGIS?

I am trying transform a UTM layer to a WGS. I have already: Saved it as a new layer changing the SRC Tried the tool "define current projection" I am using QGIS 2.14 and the original layers are in ...
2
votes
1answer
425 views

How can I improve alignment between google maps and overlays coming from a different coordinate system?

After some work, I managed to extract some PNGs out of a GIS we have at work. This GIS has some polygons in which addresses are surrounded by them. I managed to create an extractor in Python and to ...
4
votes
0answers
798 views

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) # ...
1
vote
0answers
244 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 ...
1
vote
0answers
931 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 ...
2
votes
0answers
299 views

Plotting latitude and longitude coordinates (from Bing Maps) in ArcGIS [duplicate]

I have an excel spreadsheet containing latitude and longitude values for a set of businesses. I want to plot the businesses in ArcMap. I was told the latitude and longitude values were obtained from ...
1
vote
1answer
978 views

How to convert a huge database of ED50 coordinates into WGS84?

As the title says I have a huge database containing (among other data) a pair of coordinates using ED50 standard for each record. I'm tasked to update the whole thing and convert all the ED50 entries ...
1
vote
0answers
221 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 ...
1
vote
2answers
307 views

Fix leaflet script in order to change coordinate projection

I have a leaflet script which using ziped shapefiles to add it on the map. The shapefiles are in epsg projection 31700 (dealul piscului 1970) and the position on the openstreet map is not correct, so ...
4
votes
2answers
1k views

Geotools: unexpected difference between CRS.decode(“EPSG:4326”) and DefaultGeographicCRS.WGS84

I wanted to use geotools (15.3) to reproject data from EPSG:4326 to a local projection. To see if everything works as expected I printed the length of two test linestrings. The expected result is ...
2
votes
1answer
134 views

Reprojecting points in NAD 1983 to LLA (WGS84)?

I've read documentation about using NAD_1983_To_WGS_1984_1 for the entire North American continent or NAD_1983_To_WGS_1984_5 for the 48 contiguous United States but what I'm confused is how can I use ...
2
votes
1answer
69 views

multiple glitches in rendered rasterfile after reprojecting in QGIS

I reprojected a natural earth raster file (Natural Earth II with Shaded Relief, Water, and Drainages, CRS WGS84) with a costum CRS (azimuthal orthografic) using Raster->Projections->Warp in QGIS. ...
4
votes
1answer
196 views

QGIS project crashes when project CRS is changed and all layers are activated

My QGIS project has four vector layers, three of them are from the NaturalEarth dataset (countries, regions and ocean layer). The other two are shapefiles for plant locations and plant names. Whenever ...
2
votes
1answer
347 views

How does a Spatial Reference System change the underlying geoid without having to update coordinates?

Reading Wikipedia on WGS84 I see this, Currently, WGS 84 uses the EGM96 (Earth Gravitational Model 1996) geoid, revised in 2004. This geoid defines the nominal sea level surface by means of a ...
7
votes
4answers
811 views

How does a Spatial Reference System like WGS84 have an elipsoid and a geoid?

I found out that WGS84 is an ellipsoid with a "geoid component", but I'm unsure exactly how that can be. This is from PostGIS in Action, Second Edition (pg. 64), but it seemed a bit vague. ...
2
votes
0answers
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) > ...
2
votes
2answers
411 views

How to change Datum to WGS 84?

I have a shapefile with following projection information: PROJCS["kl2",GEOGCS["kl3",DATUM["D_Everest_1830",SPHEROID["Everest_1830",6377299.36,300.8017]],PRIMEM["Greenwich",0.0],UNIT["Degree",0....
2
votes
2answers
374 views

Converting PLUTO coordinate reference system in QGIS?

I am using New York's PLUTO lot data in QGIS for a project. Right now, the shp file automatically imports with a custom CRS, allowing it to visually line up with a separate layer of subway entrances ...
0
votes
1answer
311 views

Leaflet JS: Tiles misaligned using WMS resource

in Leaflet JS I instantiated a WMS tile layer object, given a base URL of the WMS service. The wms service projection system is EPSG:32633 (WGS 84 / UTM zone 33N) and I had to use proj4js to project ...
6
votes
3answers
4k views

Which is the most accurate method of measuring distance?

I aim to analyse the accuracy of the various methods of geodesic calculations (distance between two points on Earth)based on the three assumed models of Earth - flat, spherical & ellipsoidal. I ...
1
vote
2answers
163 views

Using a geotagged jpg in the WGS coordinate system

I am working on software for mapping purposes and ran into a projection issue that is beyond my knowledge of GIS. The software utilizes longitude latitude for all visual mapping in order to maintain ...
1
vote
1answer
472 views

WGS84 to OSGB36 relative accuracy

I have dGPS positions collected using a Leica 1200 system (base station and rover) recorded at the same site on multiple occasions over two years (being used to georeference terrestrial laser scanner ...
5
votes
2answers
2k views

How does QGIS calculate distances when the data is not projected (WGS84)?

I am playing a bit around with Qgis 2.14.6 to understand how it deals with distance measurement. I took a line-shapefile that I saved in 3 different coordinate systems (4326, 32642 and a national one ...
3
votes
1answer
2k views

Transformation Parameters from ETRS89 (2004) to WGS84

I have XYZ coordinates of a point measured in year 2004 in ETRS89 coordinate system and I need to transform it to geodetic coordinates in WGS84. Since ETRS89 changes yearly, so do the transformation ...
3
votes
1answer
720 views

R: Return the UTM zone that a WGS84 point belongs to

I'm looking for an R function that might work similarly to this website that will tell you what UTM zone your WGS84 point belongs to. http://www.rcn.montana.edu/resources/converter.aspx
3
votes
3answers
1k views

Convert from EPSG:27700 to latitude and longitude

I'm trying to transform EPSG:27700 coordinates to latitude and longitude. From my research I understand that WGS 84 (EPSG:4326) is the SRS that resembles latitude and longitude. I'm using Proj4j to ...
3
votes
1answer
136 views

Issue converting projected coordinates to wgs1984 in Postgis

I'm trying to convert a local PCS (city of Buenos Aires) to wgs1984. Since the PCS is not included in Postgis, I added it to spatial_ref_sys using spatialreference.org (I compared the arguments with a ...
0
votes
2answers
620 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.
3
votes
0answers
377 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 ...
4
votes
2answers
1k views

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 ...
1
vote
0answers
86 views

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 + ...
4
votes
1answer
119 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 ...
1
vote
2answers
460 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 ...
0
votes
1answer
281 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 ...
2
votes
1answer
481 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 ...
2
votes
1answer
790 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 ...