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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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
32 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
98 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 ...
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1answer
479 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 = ...
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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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48 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
55 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
50 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
405 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
23 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
24 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
27 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
128 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
35 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
85 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? ...
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2answers
295 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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1answer
79 views

Writing shapefile with projection defined crashes fiona

I've just started trying to use Fiona to write out shapefiles. I found the example code below, which seems to work fine from shapely.geometry import mapping, Polygon import fiona # Here's an example ...
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3answers
45 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
63 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 ...
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1answer
21 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
59 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
182 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 ...
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2answers
71 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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22 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
315 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 ...
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2answers
761 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
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2answers
33 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 ...
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0answers
39 views

How to find Latitudes and Longitudes of projections of the vertices of a rectangular plane below earth's surface?

I want to find out the latitudes and longitudes of projections of the vertices of a rectangular plane inside the earth's surface. I know dimensions of rectangle, angles of orientation and latitude and ...
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1answer
57 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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23 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 ...
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1answer
59 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" ...
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1answer
37 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
66 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, ...
0
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1answer
58 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
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3answers
18k 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.
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1answer
41 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 ...
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1answer
106 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 ...
18
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3answers
13k views

Layers with same coordinate system should align/overlap but do not?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
3
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1answer
320 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
124 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 ...
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2answers
71 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 ...
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1answer
156 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 ...
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1answer
19 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
34 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
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1answer
117 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 ...
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2answers
84 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
55 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
59 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 ...