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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25 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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1answer
247 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
98 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
52 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
600 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
784 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
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2answers
52 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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1answer
63 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
35 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
71 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
84 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
117 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 ...
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3answers
6k 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
118 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 ...
25
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3answers
21k 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
64 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
174 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
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1answer
454 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
138 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
90 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
226 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
22 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
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1answer
127 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
111 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
83 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 ...
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1answer
95 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 ...
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1answer
51 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
47 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
94 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?
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1answer
54 views

Calling QgsProjectionSelector from QGIS Python plugin?

I am trying to create a dialog that allows the user to select a coordinate system from either the recently used projections or a general list of all available projections. This would basically offer ...
2
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2answers
155 views

Adding Geographic Coordinate System and Projected Coordinate System layers

So I have two layers that I am adding into ArcMap. I know for a fact that when you added the first layer with Projected Coordinated System, the 2nd layer, which has a geographic coordinate system ...
1
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1answer
105 views

Which UTM zone 32N with prefix should I use in Rhineland-Palatinate (Germany)?

I would like to store and use GIS-Data in Rhineland-Palatinate (Germany). The coordinate System should be UTM 32N with 32 as prefix (false easting = 32,500,000; not 500,000). I looked at EPSG 4647 ...
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1answer
140 views

Help defining custom CRS in QGIS 2.2

I'm trying to use EPSG:4479 in QGIS. 1) If I search for EPSG:4479, it returns a "Imported from GDAL" EPSG:4479, but it does not work. At the console, the following message is displayed: ERROR 6: ...
1
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1answer
48 views

QGIS Digitizing in Cartesian

I have a client, that needs some geological maps digitized (polygons) in a Cartesian grid. It would be a basic, square grid with North up, and coordinates in x and y. Some of the maps will need to ...
1
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0answers
99 views

Calculating closest distances in meters/kilometers given lat/long coordinates?

I am using ArcGIS 10.2 for Desktop. I have a shape file containing points worldwide with lat and long, and another world map polygon file whose Geographic Coordinate System is GCS_WGS_1984 and Datum ...
6
votes
3answers
333 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 ...
0
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1answer
31 views

QGIS “transform error” after downloading from OpenStreetMap

Beginner's question. I am working on this tutorial: http://www.qgis.org/en/docs/training_manual/vector_analysis/basic_analysis.html After selecting WGS84 UTM zone 34S in Project Properties, I receive ...
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0answers
84 views

Creating custom CRS for India toposheets using QGIS?

Indian toposheets (pre-2000 series) of 1:50k scale are in Polyconic projection, with Everest 1956 spheroid and India-nepal datum. How do I create a custom CRS in QGIS to represent this, so that I can ...
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2answers
93 views

Georeferencing Vector Layer (shp) from Mollweide Projection to Custom CRS in QGis

the title might be a little complex. Its part of a massive project: I'm working on a fantasy world; a map, to be more specific. I basicly just started to paint a world map in Photoshop, but over time ...
14
votes
3answers
2k views

Do ArcGIS SpatialReference object factory codes correspond with EPSG numbers?

I've got a project where I'm reading in geometry objects from text files to put them in ArcSDE. These geometry objects have an associated EPSG code, and I'm looking for a way to ensure they're in the ...
0
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0answers
85 views

Java GeoTools - Getting CRS from SRID

I might confuse between two things, but I need to do some calculation on my polygons (distance, area etc.). Using the WKBReader, I'm getting the geo: WKBReader wkbReader = new WKBReader(); byte[] a = ...
0
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1answer
94 views

Persistent datum conflict error. Datums are the same

I'm clipping a number of features using other feature layers, and was careful to get everything into WGS84 beforehand, using what I thought were the proper datum transformations. Now I keep getting ...
1
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1answer
113 views

How do I create an index layer for multiple maps?

I am trying to create an index layer of just the area within the Orange lines. I am having difficulty creating this layer due to it not being a simple box area. The goal is to create a index layer, ...
2
votes
1answer
241 views

What is the range of numbers for coordinates in geographical coordinate systems

Up to now I thought the range of values in the geographic coordinate systems was: Latitude (S-N): -90 to +90 Longitude (W-E): -180 to +180 I have set the coordinate system of my ArcGIS data ...
3
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1answer
72 views

Help identifying a coordinate system

I have some "latitude" and "longitude" data that describes the Silverstone motor racing circuit in the UK. The coordinates look something like this: latitude longitude +03124.27986 +00061.07652 ...
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2answers
132 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 ...
2
votes
1answer
130 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 ...
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1answer
51 views

How to project feature class located into 3 UTM Zones?

i have created a silverlight API web map application,for Saudi Arabia country, i have created a 3 search button, once search for "X,y", the problem with me is to how to define a probability projection ...
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1answer
69 views

How to Draw/plot or identify in GoogleMaps with below PointData

How to Draw/plot or identify in GoogleMaps with below PointData? Below are the points generated from spatial cadastre software. PointName Xpos Ypos _1 341.0926 527.9615 _10 669.1454 ...