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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501 views

On python, how to generate an array of coordinates between two points

Perhaps I'm looking to a solved question, but while searching I didn't find any solution. I need to build a matrix of lat, lon values, based on two points, and a sampling rate (distance between ...
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1answer
73 views

What projection should I georeference this historical map to?

I'm using ArcGIS. I have a historical map from 1884. It has bathymetry information which I would like to compare to modern bathymetry models with as much accuracy as possible. I don't know what ...
4
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1answer
100 views

Coordinate Projection Issue in ArcGIS Pro

From an issue with buffer overlaps, there was this weird problem occurring with an intersect not matching up with the buffers in ArcGIS Pro as shown below: Upon opening the same exact buffer, with ...
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1answer
522 views

Canadian Geodetic Vertical Datum of 2013 (CGVD2013)

"Natural Resources Canada (NRCan) has released the Canadian Geodetic Vertical Datum of 2013 (CGVD2013), which is now the new reference standard for heights across Canada. This new height reference ...
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1answer
34 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 ...
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1answer
830 views

Slight translation with coordinate-transformation from Gauss-Kruger to WGS 84. Possible Reasons?

I have a number of points in Gauss-Kruger, Zone 3 that I want to convert to display them within Google-Earth. Assuming WGS84 for Google-Earth the transformed coordinated differ from the original ones ...
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2answers
252 views

Is there a command line tool for converting projection in .prj and GeoTiff to EPSG codes?

Is there a command line tool to convert a shapefile projection in the .prj file into corresponding EPSG code? I know that there is website http://prj2epsg.org/search for doing this online, but I ...
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1answer
493 views

Best Practice for HTML5 Geolocation with ArcGIS for Javascript API

My organization would prefer to use its own basemaps rather than those provided by ArcGIS Online due to the accuracy of information that is represented in them. The area we service is rapidly ...
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2answers
469 views

How to create georeferenced and projected data from hand-drawn map?

I am preparing datasets for students in a spatial statistics course for a module on spatial autoregressive models. We will use ArcGIS 10.1. The first dataset will correspond to a mythical ...
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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 ...
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2answers
640 views

Setting coordinate systems in gvSIG: Is the workflow similar to QGIS?

I am still learning how to use coordinate systems and projections, but I hope this basic question will be easy to answer. My goal is to be able to use either QGIS or gvSIG to create a simple county ...
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1answer
219 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.
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942 views

How to represent an imaginary flat world in QGIS without using a round-world CRS

Like one or two other users, I'm interested in using QGIS to map an imaginary flat world. A previous answer suggested simply refraining from defining a CRS for such a world, but I cannot seem to make ...
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2answers
394 views

Geographic co-ordinate system displayed as projected

ArcGIS suite of software categorises coordinate systems as either geographic or projected. From what I understand about coordinate systems (and I may be wrong), geographic co-ordinate systems are used ...
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1answer
44 views

Converting from one Transverse Mercator based system to another produces inconsistencies

As a civil engineer, the one semester of survey training we had leaves my knowledge quite lacking in the field of coordinate systems. We're working on a project based in Gabon and we get information ...
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1answer
43 views

Linking Data Frames with Different Coordinate Systems

I have a problem that I am hoping might have multiple solutions. I am working with research data that was collected on an arbitrary grid, with units in m, datum point of 1000E, 1000N. The grid is ...
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1answer
161 views

How to correctly import a raster file with these metadatas into Tilemill?

I have a GeoTIFF file for which gdalsrsinfo reports this: PROJ.4 : '+proj=utm +zone=32 +datum=WGS84 +units=m +no_defs ' OGC WKT : PROJCS["WGS 84 / UTM zone 32N", GEOGCS["WGS 84", ...
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1answer
134 views

Explaining gap between Robinson WGS84 (EPSG 54030) in QGIS and ArcMap?

Does anybody know why there a gap appearing between two point layers create with ESRI and QGIS when I a reproject, from the same source file, to Robinson ? The source coordinate system and ...
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1answer
79 views

How to center a user-defined CRS on an area of interest?

My study extent in central Iran straddles two UTM zones (39 and 40): I would like to create a user-defined CRS in Transverse Mercator projection with central meridian inside this area. Through ...
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1answer
112 views

Point Coordinates Conversion with unknown system

I've been using QGis for few weeks now. Although this site always came very helpful, I can't find solution to my recent problem: I have few points, and know their coordinates in "WGS-84" and "ISN-93" ...
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1answer
5k views

How to calculate grid convergence (True North to Grid North)?

I would like to know how to calculate the grid convergence angle between True North and Grid North for UTM maps. I am using ArcGIS 10.0 (ArcView licence) and have used the Calculate Grid ...
4
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2answers
156 views

towgs Definition for European Datum 1950

I am new to all things GIS so apologies for a basic questions. I am trying to specify the CRS of a climatic raster layer in R. It is an equal area projection based on Europe Equidistant Conic and the ...
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1answer
189 views

How to bulk import ESRI projections into Postgis

Where can I get a file that would allow me to bulk upload all of the ESRI projections into the spatial_ref_sys table of postgis. I know that you can get insert statements on spatialreference.org; ...
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1answer
7k views

What is the relationship between ITRF and WGS84?

Why are there people saying that "I am using WGS84(ITRF96)"? There are newer version of ITRF. Will WGS84 follow it? If so, what will be the influence to us?
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1answer
381 views

extracting pixel value from a table in postgresql

I have a table in postgresql that contains ID, row number, column number, pixel value and centroid of the pixel in WGS84 lat-lon system(4326). How could I extract the pixel value by giving a point in ...
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1answer
542 views

How to specify coordinate reference system (CRS) for scalebar that is different to project CRS?

Is it possible to specify a coordinate reference system (CRS) for the scalebar that is different to the project CRS? For example, my project CRS uses geographic coordinates (lat/long), the reason ...
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1answer
521 views

EPSG operations and operation methods

Querying through the EPSG database, I can see the tables epsg_coordoperation where transforms and conversions between different CRS are stored, and epsg_coordoperationmethod which stores the ...
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1answer
3k views

Convert Gauss-Kruger to UTM

How to covert Gauss-Kruger coordinates to UTM coordinates with GeoTools java library? As I have figured out the location (zone, country) is important. I need the calculation for Slovenia.
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1answer
48 views

How to use Prolong Line feature with an input layer in WGS84?

I have a source point table in SRID:4326, and to make it look geographically accurate, I project my project file to SRID:2877 (State Plane CO) (layer still reports source CRS of SRID:4326). In order ...
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2answers
163 views

Merging rasters in QGIS?

I have 3 modis tiles that I want to merge together. They were all reprojected in the same CRS (from sinusoidal to WGS84 UTM zone 32 N), but I cannot succeed. I have tried with merge and virtual ...
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1answer
160 views

How do I find/define a projection that gives me exact relative positions inside an area?

Assuming that a set of positions are all inside a 5km square area: How do I find/define a projection to reproject the positions, so that the relative positions between the now reprojected positions ...
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2answers
2k views

Difference between latitude and longitude

It occurred to me that latitude and longitude are not homologous in that the lines of latitude lie on parallel planes or slices through Earth, while lines of longitude are not parallel and meet at the ...
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1answer
351 views

QGIS “ERROR 6: No translation for Lambert_Conformal_Conic to PROJ.4 format is known.”

I am trying to clip a county DEM file using the PLSS Section shape files as mask layers... that is, I want it clipped to sections so that I can load my DEM into QGIS one section at a time, without ...
4
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1answer
131 views

proj.4 definition for (obsolete) UK War Office “Italy South” grid

I'm helping a friend convert his late father's war diary coordinates to WGS84. I have a proj.4 definition that appears to work in QGIS, but if I transform a scanned map with gdalwarp, it's not even ...
4
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1answer
1k 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) ...
4
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1answer
194 views

Problem with custom projection definition in Qgis

I want to define a custom crs valid for Mexico. The context is that older cartography in Mexico is based on the NAD27 datum. I wanted to test the following proj4 string +proj=longlat +ellps=clrk66 ...
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1answer
431 views

NAD83 and NAD83 State Plane

I'm struggling with a projection question. I have some data in California State Plane and am trying to align a NED with NAD83. I thought these would just natively align, but they don't seem to ...
4
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1answer
726 views

QGIS custom CRS for map of manufacturing shop floor

I'm working on a web app that shows a map of a manufacturing plant's shop floor. I've built it in Inkscape and QGIS, but when I try to load it into Tilemill, I get a CRS error. Specifically, it ...
4
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2answers
2k views

Create custom projection using either QGIS (or ArcGIS Desktop)?

I have searched for an answer to this but don't see anything relating to what I am trying to do. What I have are a series of Geographic Coordinates, Latitude, Longitude, Ellipsoid heights. What I ...
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1answer
709 views

How to define a CRS using a projection rotated about a given point

I have a data set that uses a common projection, but has its own false easting and northing, and is rotated 315 degrees. I need to be able to work in this CRS and easily translate from one CRS to ...
4
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1answer
924 views

What's the correct way to reproject a population raster?

I'm working with a population raster that is in the WGS84 coordinate system, and I want to get it into a projected coordinate system (Albers Equal Area), using ArcGIS 10.1. According to the metadata, ...
4
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2answers
3k views

What formula is used for distance between 2 points in Google Maps?

What formula is used by Google Maps for calculating the shortest distance between 2 points (having their Lat, Lng coordinates)? Is it purely based on Haversine? Or is it something different? Is there ...
4
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1answer
296 views

How to change the settings for where ArcGIS splits world data

I have a world map made up of 6 shp files. All the files and the data frame are set to WGS84. The way Arc 10 and 10.1 decides to display the files, it splits Russia into 2. The majority of Russia ...
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1answer
1k views

How to delete coordinate system from raster file with prj.adf?

How can I delete the coordinate system from a raster file like .adf which is multiple files? I found a file with tha name "prj.adf" so if I delete this file is it enough? In shapefiles usually Ι ...
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2answers
367 views

geocoding addresses specifically into NAD1983 or converting X,Y into 1983 after geocoding

I'm going bananas trying to geocode addresses into a NAD1983. I have ArcMap 10.1 and I'm using the default address locator (North American 10.0 from arcgis online). No matter how low I set the ...
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1answer
324 views

Projecting gps data to get length of resulting line shape in ArcMap 10.0

I have gps data in WGS84 geographic coordinates. I will use the gps data to build a line shape in ArcMap 10.0. The data falls in UTM 15N. To get most accurate length of line, should I project the ...
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1answer
99 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 ...
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57 views

How to interpolate within defined boundaries of a deformed mesh using R?

My goal is to create an interpolation map of some output model results that are mapped on a deformed mesh (from a numerical simulation). The model results are in an x-y plane (representing ...
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1answer
45 views

Can Irish points be accurately represented by British OS Grid references?

I'm currently working in a database which stores mainland British locations as their Ordinance Survey Northing/Easting values. Can points in Ireland (primarily Northern Ireland) be accurately ...
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417 views

Hexagon binning using Google Maps

I have a bunch of geolocated points that I am looking to cluster on a google map using hexagons. These clusters will be stored in a db for quick retrieval and will be reduced to a single point and ...