A reference framework consisting of a set of points, lines, and/or surfaces, and a set of rules, used to define the positions of points in space in either two or three dimensions.

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1answer
25 views

QGIS Pre-set CRS/projections missing/unavailable

I am using QGIS 2.0.1 running off of a Ubuntu computer. I have been going through some basic tutorials (http://fossgeo.org/free-qgis-courses/) and have come up against a small and silly little ...
-1
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0answers
22 views

Learning GIS basics? [on hold]

I recently got to know about GIS. Can you tell me please what do I need to start learning GIS book references or any other reference. Also what do I need to have on my laptop for GIS (application or ...
1
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1answer
56 views

voronoi / thiessen different CRS

I have the following problem in QGIS: I try to create voronoi polygons based on a shapefile (points; standard WGS84). The newly created voronoi polygons layer seems to be ok for the WGS84 CRS. But ...
1
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0answers
19 views

Python error when using r.reclass on raster with no CRS

I have a set of GRID data (directory of .adf files) that I'm trying to reclassify in QGIS. I'm using the GRASS r.reclass function to try to reclassify the layers, but GRASS keeps failing and ...
0
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0answers
35 views

Why is the project tool in ArcGIS (ArcMap) for desktop throwing the “invalid geographic transformation” error?

I'm trying to reproject a point shapefile from ITRF92 to WGS84 UTM ZONE 14 NORTH. On the geographic transformation input field, I copied and pasted the following geographic transformations from the ...
1
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1answer
41 views

Coordinates are wrong

I thought that I solved my problem, but I am just facing another one. In the QGIS 2.13.2 version I have a google map and a shapefile. Now I want to print it with all the necessary items, but I have ...
8
votes
3answers
356 views

Does transforming to a new projection, then back, affect data accuracy?

I have a feature class (South Carolina counties, so a fairly large geographic area) in NAD83 SC State Plane. It needs to be transformed to a second projection (NAD83 UTM 17), then transformed back to ...
0
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0answers
29 views

Coordinate system for the State of California

I need to calculate, for the whole state of California, the hectares per type of crop. To do that, I have to project my layers. Because I need to work with all of the area of California, I think I ...
1
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0answers
12 views

Leica Cyclone 5.1 TLS Data referencing using Trimble DGPS

I am using a Leica HDS3000 Terrestrial Laser Scanner (TLS) and Cyclone version 5.1 to acquire and process point clouds. Within the manual for Cyclone 5.1, Leica mentions that a user can enter the ...
4
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2answers
4k views

How to convert 6 & 7 digit coordinates to degrees latitude & longitude

I'm a bit new to the whole GIS world, and though I am making great headway drawing polygons and such in Bing Maps, I am currently stuck. In our SQL spatial data, I came across MULTIPOLYGON data, where ...
1
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2answers
94 views

Why do my points end up in Africa? (should be Croatia)

I have the correct coordinates in a excel file, but when I import the file, the point always goes to the wrong place. (I need it in Croatia, and it puts the point in Africa) I've tried chaging CRS ...
1
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0answers
13 views

QGIS: Points in Polyon with two different CRS [duplicate]

I'm relatively new to QGIS. I've got a layer that shows the boundaries of the wards in the UK. In addition to this, I've got a csv file, which has long/lat plus an answer (binary). The problem is, ...
1
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1answer
15 views

Projected Coordinate System for South Australia

I am calculating areas of polygons and distances between points in a small park in South Australia (~ 139.4 longitude, -34.3 latitude). All of these points are currently in GCS WGS 1984, and the ...
1
vote
1answer
616 views

Geoprocessing tool not executing when Map's SpatialReference is Web Mercartor

I am facing a strange issue when trying to execute GP service when my map's spatial-reference is Web Mercator. I appreciate all help. I have a JavaScript API application. Initially I only had my map ...
4
votes
3answers
18 views

gdalwarp to geographic coordinate system

I'm getting the folllowing Error when trying to re-project a raster from NAD_1983_Albers to GCS_North_American_1983. I used the proj4 defenition from going to Properties in QGIS of the layer whose ...
1
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0answers
13 views

Export/print QGis: dismatching OSM data on an OSM-layer

On QGIS (2.10, winXP). is there any known problem by exporting or printing .osm-data (from JOSM) onto an Openstreetmap-Mapnik-layer? The imported waypoints always shift from the left less and less ...
2
votes
1answer
198 views

How to convert GDA eastings/northings to WGS84 lat/long in QGIS

I'm using QGIS to map weed locations and have a mixture of data from GPS, shape files of contours, OSM all in a project with CRS WGS84 (lat, long). I am trying to add in a shape file I have been given ...
4
votes
1answer
69 views

convert lat/lng to pixel and vice versa

This had been asked previously on Stack Overflow. I've tried different methods/formulas but results are not correct. 40.764296,-73.97302 should result into 930,3590 pixel on map image. I've Manhattan ...
1
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0answers
25 views

How to perform statistical test for two sets of points?

(I have asked this question originally on Cross Validated; however, no good answer and someone suggested me to ask the question here). We know that we can perform statistical test (e.g., t-test) for ...
1
vote
3answers
138 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 ...
3
votes
2answers
45 views

PostGIS raster - [x,y] from lat/lon

I have coordinates in [lat, lon]. How can I convert them to the rasters "pixel" position [x, y]? I know raster top-left corner, scale and skew.
1
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0answers
21 views

Updating mapnik stylesheet to render WGS84?

We have a production tile server loaded using osm2pgsql serving osm-bright, osm-carto and osm-mapquest style tiles and would like to be able to server those in WGS84 projection, as well. I've tried ...
3
votes
1answer
659 views

PostGIS: ST_Transform function conversion problem

I'm inserting map data from a GML file with srid EPSG:27700 into a PostGIS database table with srid EPSG:4326. I'm using the ST_Transform function as in this snippet: ...
2
votes
2answers
58 views

How to get an area Latlong geometry directly from google map?

I am new to field of GIS. I need to know that do we have an option of getting latlong of a building that we see in google earth or any Point of Interest areas. Something like i create & drag ...
5
votes
3answers
639 views

How to define layer's CRS and avoid the CRS dialog in PyQGIS?

There is an existing Shapefile, which I want to add. At the moment my code looks like: self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr") It works fine, but i want to define the crs ...
2
votes
1answer
54 views

How to display different layers with different CRS in one canvas in a standalone application?

I am a freshman of the pyqgis. Now I load the raster and vector data in the standalone application. The two data are same area, but in my canvas, they are at different places. I want to know how to ...
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 ...
2
votes
1answer
193 views

Locating British National Grid Eastings/Northings in ArcGIS Pro i.e. ArcMap Go To XY equivalent?

In ArcGIS Pro is there a way to search for Eastings and Northings for Britain, similar to the Go to XY in ArcMap?
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2answers
30 views

Projection for using ArcGIS as CAD [closed]

I want to use ArcGIS to map my apartment. How can I create a projection file (with which parameters)?
3
votes
2answers
46 views

How to re-project a shapefile to be compatible with another shapefile or raster?

I have a polygon shapefile and a raster. The shapefile and raster have different coordinate systems. Coordinate System for the shapefile: NAD_1983_UTM_Zone_19N WKID: 26919 Authority: EPSG ...
1
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0answers
28 views

In OpenLayers 3, transformExtent to EPSG:8155 produces error

I'm trying to get the extent of a map using OpenLayers 3, so that I can use it in a CQL filter to limit the area of the WMS request to the area currently shown in the map extent. To do this, I have to ...
5
votes
1answer
49 views

Shapefile projections not matching up in QGIS?

To start off with, I'm very new to QGIS. I'm attempting to place a shapefile with locations for 3 substations on a map of Peniche, Portugal. The locations for the substations are given in latitude and ...
1
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0answers
31 views

Choosing CRS to use for South Africa that will give map scale in meters in QGIS?

This has been a constant source of frustration for me. I can't seem to always get my map scale in meters in QGIS, even if I use a CRS that has map units of meters, e.g. Alberts Equal Area and others. ...
2
votes
2answers
358 views

Different definition of EPSG:3857 in GeoTools and QGIS

I want to do some checking if my point lies in any of the polygons defined in shapefile. So, I thought that I will determine CRS from shapefile (created in QGIS), and use it for transformation (where ...
2
votes
2answers
239 views

How to reproject from Clarke_1880_RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA?

I am unable to reproject Marseille shapefiles from Clarke 1880 RGS_Lambert_Conformal_Conic to ETRS_1989_LAEA. I know that Clarke is a geographic coordinate system and it has no datum. I have tried ...
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votes
1answer
34 views

How to check based on GPS coordinates if point is near a given path? [closed]

Path is just a straight line defined by coordinates of the beginning and end of it. My coordinates are simply longitude and latitude of three points: start of the path end of the path my point (for ...
6
votes
2answers
118 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) ...
1
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0answers
77 views

Determining accuracy of coordinates from handheld GPS?

I'm working on a project for class, and I'm mapping GPS on Google Earth with a KMZ file. I used a handheld GPS 24°6.691'N + 74°27.833'W. How accurate is my coordinates? I know I'm in decimal ...
1
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0answers
60 views

Strategies and methods that Datums and Coordinate Systems use to account for movement of the earth's surface

Are there datums and coordinate systems that address the issue of shifting coordinates through time? If so, what are some of the strategies and methods that the datums and coordinate systems use to ...
4
votes
2answers
3k views

Setting spatial reference to OSGB_1936_British_National_Grid in ArcGIS Desktop?

I have two datasets in ArcGIS Desktop. One is from the Ordnance Survey (UK National Mapping Agency) and, when I view the properties of the dataset it says that the Spatial Reference is ...
6
votes
2answers
55 views

Inferring lat/lon based on known location coordinates

I have a point dataset with a set of coordinates that is in an unknown projection. For some of these points I know the unprojected latitude and longitude. Based on these known data points, would it be ...
1
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0answers
31 views

Get distances between boundaries from an SpatialPolygon and raster pixels

I am trying to calculate the distance from several pixels of a raster to a boundary of some polygons in R as it is showed in the image. I have two problems: How to correctly define a boundary from ...
1
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0answers
53 views

Calculating areas in metric units on polygons that are stored in geographic coordinate reference system using ArcPy?

If one uses arcpy to calculate areas for a field in metric units on a polygon shapefile in a geographic coordinate system it will work, and give you plausible results. According to the documentation ...
0
votes
1answer
185 views

GeoTools, convert CRS for Google Maps

I'm trying to use GeoTools to convert coordinates from EPSG:3857 to various CRS, in order to display WMS layers on a Google Map. For example, I want to display a layer in the EPSG:4326 CRS. I have ...
1
vote
1answer
57 views

Choosing projection to make Arizona look “normal”?

I am having issues projecting my AZ state boundary from looking like this: to looking like this: I found that I could use the U.S. National Atlas Equal Area to get the shape I want, but when I ...
1
vote
1answer
45 views

Reprojection issue from WGS84 to UTM32

In QGIS I want to transform a point shapefile from WGS84 to UTM32 (EPSG:4647). The result moves the point from somewhere in Norway to a position off the coast of Congo, Africa. Can anyone explain ...
2
votes
0answers
22 views

Does ETRS89 and UTM use the same zone (longitude and latitude)?

I'm building an app for the european country Denmark exclusively and I need to retrieve some geospatial data from a (geo)server. I'm currently trying to determine wether UTM and ETRS89 uses the same ...
2
votes
1answer
240 views

How to access Leaflet EPSG:3857 coordinates?

I read everywhere that Leaflet is internally using a spherical web mercator (EPSG:3857), but whatever I try I get either Lat/Lon (EPSG:4326) or strange coordinates I dont understand: ...
2
votes
1answer
31 views

Mapping out 3D points with QGIS2threejs

I have some points I would like to map out in 3D. The points were gotten from a GPS module athat was attached to a Raspberry Pi. This is the settings I used before starting qgis2threejs: This was ...
1
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1answer
36 views

Repositioning DXF Imported into QGIS?

I have a polyline drawing from AutoCAD that I would like to reposition manually, if possible. During my efforts so far it has been turned into both a tab file and shape file. The main source of ...