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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21
votes
8answers
17k views

ArcCatalog complains that spatial references don't match between a feature dataset and a feature class that have the same coordinate system?

I have a feature dataset that is using the GCS_WGS_1984 as the geographic coordinate system. It includes a few feature classes. This feature dataset is itself in a file geodatabase that contains a ...
6
votes
1answer
9k views

Converting geographic coordinate system in R

I have points in geographic coordinate system and I wanted to convert them to swiss grid (CH1903+). Sample data: id lon lat 2 7.173500 45.86880 3 7.172540 45.86887 4 7.171636 45....
9
votes
3answers
14k views

Understanding Coordinate System Transformation in ArcMap?

For the Data Frame Properties on a map in ArcMap, what is the difference between selecting a new coordinate system and using a Transformation?
4
votes
3answers
11k views

Which CRS to use for Google Maps?

I am trying to map a Shapefile (download) onto a Google Map using the Javascript API. The Shapefile describes the boundaries of NYC School Districts. The file's projection was Lambert Conformal Conic,...
5
votes
2answers
22k views

Coordinate system and projection for georeferencing Google Maps image in ArcGIS Desktop?

I have saved Google Maps image (not Google Earth) of area at latlon(17.692437,83.218689) by some method in jpeg format. It is an exact snapshot of the Google Maps. Now I need to geo-reference it to ...
7
votes
1answer
274 views

Understanding difference between Coordinate System and Projection?

Can somebody please explain what is the difference between the Coordinate system (WGS 84 for example) and a Projection (Universal Transverse Mercator for example)? What is the difference between a ...
3
votes
1answer
251 views

Why not measure elevation from the center of the earth?

In trying to understand Geoid vs Ellipsoid height, I ran across this page. One of the claims is: Zero elevation as defined by Spain is not the same zero elevation defined by Canada Basically,...
2
votes
1answer
551 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: map.getBounds()....
26
votes
3answers
3k views

What was the rationale for the non-standard UTM zones near Norway?

UTM zones 30V, 31V, 32V, 31X, 33X, 35X, and 37X do not line up with the rest of the UTM zone grid. Why was this allowed? According to Wikipedia, UTM was developed by the U.S. Army Corps of ...
9
votes
2answers
8k views

How do I convert affine coordinates to lat/lng?

I am extremely new to GIS. I'm using gdal to read in a landuse/landcover map and I need to pick out the lat/lng of certain land cover types to index into a different dataset which is expressed only ...
6
votes
2answers
2k views

Describing a coordinate system in arcpy

I have a python script in ArcGIS 10.1 which takes in a few inputs from the user. One of the inputs is a coordinate system. I would like to test whether the coordinate system the user chose was ...
5
votes
2answers
1k views

How to properly open an ASTER data?

Yesterday i downloaded an Aster L1B image from USGS's website. If i load it in QGIS, it doesn't get displayed properly(location wise). Even after i've enabled "On the fly" option, it's not reading the ...
4
votes
2answers
3k views

ogr2ogr srs options: where is the well known definition determined?

In the ogr2ogr documentation it says that when using -a_srs srs_def: Srs_def can be a full WKT definition (hard to escape properly), or a well known definition (ie. EPSG:4326) or a file with a WKT ...
3
votes
1answer
2k views

How to assign CRS to RasterLayer in R

I have a layer with coord. ref. : NA. How can I assign coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0 to coord. ref. : NA? class : RasterLayer dimensions : 127,...
3
votes
1answer
681 views

Programmatically Select a CRS in QGIS 2.4 using Python

When you run the following Python code in the Python Console of QGIS 2.4, uri = "file:///C:/data.csv?type=csv&xField=lng&yField=lat&spatialIndex=no&subsetIndex=no&watchFile=no" ...
3
votes
1answer
159 views

Difference between datum and ellipsoid for geodetic coordinates?

Looking at the Wikipedia page for the North American Datum, it seems to imply that the datum is completely defined by the ellipsoid, which defines the major/semi-major axes, flattening, etc. For ...
2
votes
1answer
157 views

Coordinate system doesn't contain values in the range -180 to 180 and -90 to 90

I'm creating an android version of a PC program (I've contacted the company who owns the PC program, so it's legal). The program is in the core a GPS, but is used to navigate pre-defined routes for ...
13
votes
3answers
6k views

Official term for latitude longitude coordinate system?

May I know what is the correct specific term for latitude longitude coordinate system? With "Geographic Coordinate", it seems to be a general term for every other system?
10
votes
2answers
1k views

What happens to feature class when importing to feature dataset?

I am creating a model that needs to ensure that all input datasets end up in the same coordinate system (among other things). I was originally going to batch project all of the datasets whether they ...
8
votes
2answers
2k views

Is there a standard for the specification of .prj files?

We use shape files for data exchange. I've looked at the .prj files: different programs produce different prj files. Is there a standard how the parameters must be specified in a prj file? AFAIK the ...
7
votes
2answers
1k views

How to Georeference Photos With No Spatial Reference?

I have about 100-200 field ground shot photos I would like to overlay in ArcGIS 10 that have no spatial information which I need to somehow develop using a photogrammetric formula. The camera was ...
7
votes
3answers
1k views

Using PROJ.4 library to transform from local coordinate system coordinates to global coordinate system using ground control points?

I have a point cloud whose coordinates are with respect to a local coordinate system. I also have ground control points with GPS values. Can I convert these local coordinates to a global coordinate ...
6
votes
2answers
2k views

How To Use Tiled Map Services with Different Spatial References in ArcGIS API for JavaScript?

I have the following code fragment in an esri page to try and change basemaps, the following code works, unless the next basemap layer uses a different spatialreference. if (baseMap) _map....
5
votes
2answers
1k views

Quick way to determine if facing a given lat/lon pair with a heading

I'm looking for a fast way, preferably without trigonometric operations (just multiply, divide, add, sqrt and subtract) to determine if a point is visible. E.g. say I am facing 0 degrees N, I am at 51....
5
votes
2answers
2k views

Does anyone know the proj4 Coordinte Reference System command line for Rectangular Polyconic Gores?

I am a GIS beginner using QGIS 1.8.0 I am trying to transform a world map from the standard WGS84 Coordinate Projection System to a set of rectangular polyconic gores, with a gore count of 12. ...
5
votes
1answer
2k views

MGRS in OpenLayers

I am trying to view the Military Grid Reference System coordinates in Openlayers through the MousePosition control. Is there an easy way to accomplish this just through Javascript? I am looking at the ...
4
votes
0answers
249 views

What projection system is used in China which is aligned with WGS84 [closed]

I have some GPS tracks in Beijing. I want to project it and convert the lat long degree values in meters for calculation in euclidian space. I was wondering what is the most suitable coordinate and ...
4
votes
2answers
1k views

Using Spatial References with ArcPy after *.prj files no longer installed by ArcGIS 10.1 for Desktop?

I'm writing a python script that uses the CreateFeatureclass_management tool, without a template. One of the required parameters is a spatial reference. I used to be able to point to the system *.prj ...
4
votes
4answers
15k views

Getting shapefile in right projection using ArcGIS Desktop? [duplicate]

I have an older map that I didn't create. I'm just trying to get everything to line up on it, and having a hard time. The data frame is in NAD_1927_UTM_Zone_12N, as are the point shapefiles (derived ...
4
votes
1answer
237 views

Choosing Projection for Gulf coast region of USA?

What are the most appropriate datum and projection I could use for the Gulf coast region - spanning Louisiana, Mississippi, Alabama, and Florida? I have to analyze block group data along the coast.
4
votes
1answer
36 views

What is the level of error I should expect when using a NAD StatePlane CRS from an adjacent state?

I am adding Georgia data to my GIS database and, unlike the California data I've added, have decided to use my existing EPSG:3361 (South Carolina StatePlane) coordinate reference system for ...
4
votes
2answers
4k views

QPJ files on ESRI software

We have some GIS data, which was converted from AutoCAD dwg to TAB using mapinfo, then converted to shapefiles as that's what we are required to create. Editing the data fields was done in the shape ...
3
votes
1answer
149 views

Rhombus shaped pixels when viewing an image referenced in WGS84

Following the Question What is the projection of WGS84 in GIS software?, in the comments section of the answer http://gis.stackexchange.com/a/73578/5256, Jake very well explains that Because the ...
3
votes
1answer
732 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: ST_Transform(ST_GeomFromGML('&...
3
votes
1answer
118 views

After how much distance does the x,y coordinate system become noticeably distorted?

I'm working with maritime sensors that give information of moving objects it detects, in azimuth, range and elevation, and we convert it to x,y coordinates for our application to be able to process it....
2
votes
1answer
507 views

Query all Object within n kilometer Radius with Hibernate Spatial?

I use hibernate spatial attach a geolocation to a car. My card domain class looks like this: import com.vividsolutions.jts.geom.Point class Card { String name Point location } My program is ...
2
votes
1answer
660 views

Change coordinate system of a WMS service

I have a WMS service that is projected to UTM/SAD-69. My workspace is in WGS-84 with no projection. I want to change the coordinate system of my WMS service. Is it possible in ArcMap 10.0? The wms ...
2
votes
2answers
758 views

What does 1:10m mean related to map resolution?

On Natural Earth they offer maps at various resolutions. What does 1:10,000,000 mean? Does it translate to the number of points per square meter or mile?
2
votes
1answer
222 views

escape the cut of western/eastern hemispheres

I am very new to QGIS and GIS in general, so I am struggling with the following: when I do a map of Russia, I get the part next to Alaska being drawn far left from Europe, as it lies behind 180o... I ...
2
votes
1answer
212 views

Question about BNG coordinate systems

I'm historically a user of MapInfo Professional but have recently started using FME and have been talked into now testing out a copy of QGIS. The main problem I've come across is that the coordinate ...
2
votes
1answer
328 views

Why is shapefile not drawing in expected location after (or before) using Define Projection tool? [duplicate]

I have downloaded this zipped shapefile of bus routes from the City of Houston data portal. I then performed these steps in ArcGIS Desktop 9.3.1: Extracted the shapefile from the *.zip Added this ...
2
votes
5answers
3k views

Convert geographic coordinates to UTM zone 29N with Javascript

I have an issue converting lat longs to UTM with the ArcGIS javscript API. Lets say that I have a map, based on the UTM zone 29N, also known as WKID 32629. I have a known set of coordinates from a ...
2
votes
2answers
830 views

How to use the coordinate system in arcgis 10?

I have a favor to ask. I have a few layers. The layers have been made by a different company. So how do I combine them all together so that they have the same coordinate systems? If there are any ...
2
votes
3answers
5k views

Code to convert WGS84 coordinates to British National Grid Easting/Northings

I'm looking for some code, ideally C#, to convert a WGS84 coordinate to British National Grid Easting and Northings. Does anyone have this to hand? I tried converting the Javascript code here: http:...
1
vote
2answers
855 views

How to fix shape file projections

I have a project with several shape files. The files overlapping however. I have to go to unusable extents to even see the file on the same screen. I have tried using to project to as suggested here ...
1
vote
3answers
6k views

How to project Google Earth KML files in ArcGIS so that they display properly?

I am sure my question has been answered in the past but I would really appreciate it if someone could help me with this... I have downloaded a KML point file from Google earth and I imported it into ...
1
vote
2answers
14k views

How Can I change the projection of shapefile in Qgis?

I have a probleme with Qgis. I would like to change the projection of my shapefile, it's about caves in my country. The default projection is set to EPSG:3003, I want to change it to wgs84 EPSG:32632. ...
0
votes
1answer
938 views

How to calculate the UTM-Latitude-band?

I have to convert a coordinate from UTM to MGRS. I think I have the most of it covered, but I have some difficulties to calculate the correct Latitude-band. How can I decide which band the coordinate ...
0
votes
2answers
208 views

Calculate length of line across zones with at least m accuracy

I have created lines between multiple points that are across MGA 54 and 55S (EPSG 28355). I am trying to calculate the distance between points but different methods give different answers (~1km ...
8
votes
1answer
6k views

getExtent() in OpenLayers returns strange values

I'm trying to get the bounding box of the map area displayed by OpenLayers. I tried to use map.getExtent() because it should be exactly what I need, but the returned values are "strange": For ...