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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90 views

ArcGIS Conversion Error While Converting ED50 Datum to WGS84 Datum

With ArcGIS for Desktop, I tried a datum conversion of Transverse Mercator ED50 Datum to Transverse Mercator WGS84 Datum. Normally, the difference between two projections is approximately 180 meters ...
2
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1answer
44 views

When to reproject LAS data?

I've downloaded a few LAS files from the NOAA: http://www.csc.noaa.gov/digitalcoast/data/coastallidar I used lasinfo to get the coordinate system of the LAS files and it returned: ...
3
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2answers
107 views

Creating raster pinned to cartesian coordinates using ArcGIS for Desktop?

I'm looking to create a raster such that the edges of the raster are aligned perfectly with the cartesian coordinates of the underlying projection. I am using a custom Lambert conformal conic ...
0
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1answer
559 views

Coordinate conversion - Lat Long to State Plane, ArcServer-Silverlight

I am trying to project a Lat/Long value I get from a table to a x/y value that I can use to plot a graphic. I have seen one way to do this may be to use something like this: feature.Geometry = ...
3
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2answers
2k 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 ...
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0answers
49 views

I'm new to GPS, and I had a quick question about clarity.

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 ...
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2answers
60 views

Any difference between EPSG:3003 and EPSG:102091?

I am working on QGIS 2.2.0. The PRS I am working on is Monte Mario / Italy zone 1 (EPSG:3003), with the following parameters: PROJCS["Monte Mario / Italy zone 1", GEOGCS["Monte Mario", ...
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1answer
59 views

Geoserver: gs:Reproject in SLD fails

I want to reproject data via sld: <?xml version="1.0" encoding="ISO-8859-1"?> <StyledLayerDescriptor version="1.0.0" xsi:schemaLocation="http://www.opengis.net/sld ...
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2answers
525 views

How to display WGS 1984 Web Mercator (Auxiliary Sphere) services in Google Earth?

The basemap services provided by Esri (on ArcGIS Online, Data and Maps for Sever, and the Data Appliance for ArcGIS) use the WGS 1984 Web Mercator (Auxiliary Sphere) spatial reference (WKIDs 102100 or ...
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1answer
30 views

Project one layer in qgis using projection CRS of another layer

I am using QGIS 1.6 and have imported a set of latitude, longitude points from a csv file as a layer. I also have another layer from a shape file. When I go to layer->properties for the second layer I ...
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3answers
3k views

Writing world file when exporting TIFF using ArcPy Mapping?

According to documentation, the options are: Syntax ExportToTIFF (map_document, out_tiff, {data_frame}, {df_export_width}, {df_export_height}, {resolution}, {world_file}, {color_mode}, ...
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2answers
25 views

“CRS selector” dialog after running a script

I add an empty vector layer using the following script. layer = QgsVectorLayer('LineString', 'MyLayer' , 'memory') QgsMapLayerRegistry.instance().addMapLayers([layer]) After I run the script, ...
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0answers
30 views

How can I define coordinate system of feature class when overlaying with coordinate zone shapes in python?

I have generated bounding boxes for CAD drawings that do not have defined coordinate system files. I know that each drawing could be in one of 6 different systems that do not overlap. My idea was to ...
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1answer
143 views

Error getting spatial reference as string in arcpy

I am trying to get the string associated with a spatial reference to print into an xml using arcpy and xml.cElementTree. Using the snippet: ... spatial_ref = arcpy.GetParameterAsText(3) ... Prj = ...
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1answer
52 views

Shifting a CAD file from ATS77 MTM 5 to NAD83 CSRS UTM 20

Looking to make the coordinate system shift in ArcMAP (for Nova Scotia) between ATS77 MTM 5 and NAD83 CSRS...NTv2 file?
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2answers
114 views

Changing layer extent to decimal degrees?

Using ArcMap or ArcGIS 10 ... In the photo below, you can see my extent is in meters while my projected coordinate system is in decimal degrees. How can I convert my layer extent to decimal degrees? ...
2
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2answers
321 views

Free .exe for coordinate transformation lat-long - UTM

I need to find a simple program for Windows which transforms lat-long to UTM. I know that there a websites to do this, but this is for use with the emergency services. The forestry commision use gps ...
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3answers
52 views

Defining custom projection using baseline survey coordinates

I have CAD data that I need to incorporate into a GIS analysis. The CAD data does not have a defined projection, but the drawings include a table of survey baseline points. I need to know if I can ...
3
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1answer
68 views

Help with “projected XY to screen xy” conversion algorithm?

I'm trying to convert coordinates from any given coordinate system (be they the coordinates of a graph figure or a map, meaning they can span across both negative and positive values across any of the ...
1
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1answer
23 views

QGIS Custom CRS has some glitches

I am georectifying scanned versions of Survey of India maps, which are in Everest spheroid and india_nepal datum. The exact parameters are: +proj=longlat +a=6377301.243 +b=6356100.2284 ...
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2answers
72 views

Coordinate System Google Maps API

I am making an application in java using GMaps4JSF where the person will enter the address on the map I'll take this coordinate and consult on my postgis base regions in which region this point is ...
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1answer
212 views

Calculate distance between two coordinates to use in variogram calculations in ordinary kriging

I need to calculate distance between two stations in a map in order to calculate empirical variogram in ordinary kriging to interpolate temperature data. Calculating distance in kriging using ...
2
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2answers
81 views

which map projection should be used for global map with geography and human demographics

I am working on a project to try to identify the most threatened populations (on a global scale) of having a limited access to freshwater. I want to compare those most at risk currently and then add ...
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0answers
27 views

I am getting NULL values when I use “point sampling tool”?

I am trying to extract values from a raster using a point shapefile, but I am getting NULL values. I think that NULL values are obtained because the Coordinate Reference System (CRS) are not the same ...
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3answers
381 views

Why some coordinate systems define x-axis as northings and some as easting?

The definition of north and east are pretty straight forward to grasp but only becomes difficult when used interchangably with x-y coordinates which have varying definitions for the direction of the ...
3
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2answers
768 views

What kind of coordinate system is this?

I have a csv with a list of the world sea ports and their coordinates. The coordinates are in this format: 5234N 00226W How can i convert this to decimal Latitude / Longitude ? Data source
2
votes
2answers
45 views

How to replicate ArcGIS coordinate transformation with ogr2ogr?

I need to be able to replicate with ogr2ogr a coordinate transformation that was executed in ArcGIS for Desktop. Both ArcGIS and ogr2ogr are based on EPSG standard definition. There's not only one ...
1
vote
1answer
58 views

Unique Natural Area Code (NAC) for a building

NAC is a geocode system for identifying an object anywhere on the Earth. I am going to assign a unique NAC address for each building in Detroit. But different NAC addressed can be assigned to each ...
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0answers
27 views

Comparing datums with GDAL/OGR

I have a bit of code in Java that takes in a SpatialReference object and checks that it is one of the acceptable datums (WGS84, NAD83, NAD83 HARN, NAD27), but because of the lack of standardization in ...
0
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1answer
63 views

How to choose a coordinate reference system

I have a jpeg image of a reserve's layout and would like to use it to plot animals movements on i.e. GPS points. I have no idea which coordinate reference system to choose during the "georeferencing" ...
0
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1answer
50 views

Clipping Rasters from Mosaic Dataset in their Original Coordinate System

I am building a large mosaic dataset that contains several hundred rasters, which are spread across three UTM zones. My goal is to be build a tool in ArcMap (most likely within model builder) that ...
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2answers
83 views

User defined Coordinate Reference System (CRS) in QGIS is not located where expected?

I have received a shapefile with a user defined projection (i.e., +proj=krovak +lat_0=-32.923433 +lon_0=116.47485 +alpha=111.423433 +k=1.00004 +x_0=44328.529781 +y_0=1345943.211845 +ellps=GRS80 ...
9
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3answers
5k views

How does ArcGIS compute the distance between two points with a non-equidistant projection?

This is a follow-up question to my previous one, Can you suggest some well-written introductory texts about coordinate system projections? Let's assume I'm working with the CH1903 map projection, ...
1
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1answer
78 views

Spatial Join in QGIS 2.2

I am trying to spatially join point layers of some 12,000 women interviewed in Egypt to Egypt's polygon layers (administrative districts boundaries) using QGIS 2.2 and need some advice. I am a QGIS ...
24
votes
3answers
19k views

What is the difference between WGS84 and EPSG4326?

What is the difference between WGS 84 and EPSG 4326? It seems like for a given dataset it might be both WGS 84 and EPSG 4326.
1
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1answer
50 views

Can I define a transformation between 2D and 3D in Geotools?

I'm using Geotools, and I need to convert coordinates between 2D and 3D coordinate reference systems. I recognize that there's no universally-correct way to do this: 2D -> 3D means "making up" a Z ...
1
vote
1answer
130 views

DotSpatial.Projections Vs. ProjNET4GeoAPI

DEAR PEOPLE FROM THE FUTURE: Here's what we've figured out so far… I have been facing the issue of transform coordinates from a custom spatial reference to a well known spatial reference (let's say ...
4
votes
1answer
376 views

In ArcObjects, how do I change the spatial reference of a Map (Data Frame) in an existing MXD?

I need to change the spatial reference of an existing MXD programmatically. In ArcMap UI, I would take the following steps: 1) Open the data frame properties and go to the Coordinate System tab; 2) ...
3
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1answer
130 views

New coordinate system?

I just had my mind blown in answer to my previous question. I was going to rework that question, but decided it makes more sense to ask a new one. I had been converting between ECEF and lat/lon, and ...
0
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2answers
78 views

Data match-up problem ArcGIS 10.1

I am running into a problem with two data sets matching up, and although it seems like a newbie coordinate system problem, it has me stumped. One data set is a GPS track (Garmin Etrex Legend 30) and ...
1
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1answer
181 views

How to identify township range and section from longitude and latitude

I have several hundred coordinates in an Excel file. I would like to identify the township range and section they are located--what is the easiest way to do this? I have you QGIS and basic GIS skills ...
0
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1answer
21 views

NAD conversion in Mexixo

I am looking for the file "Mexico.gsb" which used with ArcGIS when datum shifting from NAD27 to NAD83 in Mexico.
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0answers
36 views

Problem with projection in meters with ArcGIS 10.1 [duplicate]

I hope you can help with the following problem. I have a shapefile and want to project it using a projected coordinate system with meters as unit. What I did was to change the projection from ...
3
votes
1answer
121 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 ...
4
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2answers
95 views

How do I construct (or select) an appropriate local Cartesian coordinate system, for an arbitrary small area?

I'm relatively inexperienced with coordinate reference systems, so please bear with me if I'm not putting this clearly. I have existing software which works with an abstract (un-referenced) 3D ...
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1answer
63 views

How to convert geospatial data with a custom SRS into ESRI Shapefiles?

I want to convert geospatial data stored in a .csv file into GeoJSON or ESRI Shapefiles. The problem is that the coordinate reference system is not in the database of EPSG codes. The originator ...
0
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1answer
66 views

Spatial data not aligning after Define Projection? [duplicate]

I have three shapefiles and two buffers made from two separate shapefiles. I was trying to do a spatial join and it kept coming up with an empty file even though there was clearly overlap. I realized ...
0
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1answer
43 views

QGIS Road graph setting not configure

I am using qgis valmiera on windows 7 pro 64 bit. I am unable to configure road graph setting. Layer feature Transport layer is not highlighted. Please tell me how to solve this problem. Please tell ...
2
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1answer
39 views

In FME Desktop, I have a custom coordinate system, I was confused how to translate it for MyCoordSysDefs.fme

I have a custom coordinate system that I was confused how to translate it to the MyCoordSysDefs.fme for use in Safe Desktop. Here's how it is represented in the prj file. ...
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3answers
89 views

Create buffer in Metres

I want to create a buffer in meters around points in Europe. But I cannot find a proper CRS for Europe that is in meters instead of degrees?