A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane

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118 views

Should I Reproject Data Which Has Been Captured Incorrectly?

I'm working on a project for a client which is migrating data from an Oracle database to an ESRI Geodatabase. When data for this project was initially captured over 15 years ago, the coordinate ...
0
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0answers
67 views

export WebMap in a different projection than the WebApi

I am quite new to the Flex WebApi world. I am using the Flex WebApi and have set up map templates to print maps out to my own template as a PDF. In my template I have the Map grid set. When I eport ...
3
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1answer
148 views

CRS Austrian Lambert/WGS84

I am totally new to Qgis (or GIS in total): My problem is to get two layers in same CRS to do an intersection and further analysis described in the blog of underdark (Groupstat tutorial). My is the ...
0
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1answer
2k views

Conversion from N,E to Lat/Long And Lat/Long to N,E will always be same? [closed]

I have an excel tool for the conversion of following lat/long: Lat: 23° 11’ 24.67503’’ S Long: 118° 46’ 6.15742’’ E , which gives me following N,E: Northing: 7,434,317.43 Easting: 680,991.69 But I ...
2
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0answers
177 views

Proj4 inconsistent longitude after projection

All coordinates expressed in this question are (longitude, latitude), the default for proj4. London is at (-0.1460838, 51.5170986), and San Francisco is at (-122.419302, 37.775549). According to the ...
1
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0answers
73 views

Projection for Tracking a Vehicle

I'm looking for the best coordinate system projection to use for cartesian calculations while a vehicle is running from its starting location to about 100 miles from that spot. The offline format ...
3
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1answer
291 views

Why are two incompatible projections used together in OpenLayers? [duplicate]

While going through the examples in OpenLayers, I notice several examples with the following code: map = new OpenLayers.Map('map_element',{ ... units: 'm', projection: new ...
4
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1answer
247 views

Error in Min. Bounding Geometry results

I'm getting consistent, weird results from using Minimum Bounding Geometry to make circle polygons. I'm not sure if a datum issue, but I'm leaning more towards something wrong with Minimum Bounding ...
3
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3answers
349 views

How to reproject to other projections than WGS84 or Webmercator?

I have an OpenLayers map with a vector layer to add points on. I'm using Google Maps as the base layer. After the point is added, I need to store the data in my database as lat/long and x/y. Can I ...
7
votes
5answers
9k views

OpenLayers: ALL image layers are out of place on google maps v3 and OSM base layers

Summary: I have 2 different image layers that looked fine with my old mapstraction/google maps based system. Using the same coordinates as bounds in openlayers results in a shift to the north by like ...
4
votes
2answers
530 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 ...
4
votes
1answer
157 views

Global projection with zero scale distortion at non-zero latitude

I am looking for a global projection with zero scale distortion at non-zero latitude. I have tried using an Oblique Mercator projection centred at a specific latitude and longitude of centre (with ...
2
votes
1answer
105 views

QGIS mixing up CRS

I´ve just started working with QuantumGIS for my thesis. I ordered shapefiles with the CRS: ETRS 89 UTM Zone 33N, but QGis layer properties now shows the layer has a different CRS (namely SWERE99 TM) ...
3
votes
1answer
217 views

how can I know which projection has this data?

I have data in an unknown projection to me. I open it in QGIS and I see that the shapes are ok, but I need to identify the projection in order to merge this data with other stuff. The points look ...
11
votes
1answer
886 views

Great-circle lines in Equirectangular projection

Just to check that I'm on the right track: Are all great-circles on the sphere and in equirectangular projection (i.e. latitude, longitude pairs) either: meridians (i.e. going pole to pole) of the ...
0
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1answer
348 views

How to get DXF to show up in the right spot?

I just followed the advice of this forum post in order to export the vector layers of a PDF for usage in ArcMap. The map vector layers in the PDF were spatially referenced. I was able to export the ...
5
votes
1answer
249 views

Having trouble finding out what coordinate system a map is using, and how to convert it

I'm using Small Area shapefiles in Ireland from the Central Statistics Office (CSO) website. The link to these is here http://census.cso.ie/censusasp/saps/boundaries/ED_SA%20Disclaimer1.htm (Look for ...
3
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0answers
508 views

VBA Convert decimal degree to Meters button

I have 2 data frames one which has WGS data in it and the other OSGB1936. I am trying to create a button where the user can input decimal degrees (WGS) and it will zoom them to that location in ...
1
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0answers
135 views

What is a radar projection?

Trying to overlay a radar image(radar projection) on a mercator projected map, but have no idea about what a radar projection is. So here are my quesions: What is a radar projection? What's its ...
1
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0answers
257 views

What is UTM Zone 0?

I am currently working with some roadway link data and it is being projected in UTM. After importing the shapefile into GRASS I can view the map and it looks correct but when I view the projection ...
1
vote
1answer
604 views

What are Bands, Dimensions, and Histograms in QGIS?

First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct? If so then bands play the role of color mixing and masking. Are there any other ...
4
votes
3answers
3k views

Parameters for ED50 -> ETRS89/WGS84 seven-parameter transformation which are good for Denmark?

I am looking for parameters for a seven-parameter transformation (Rx, Ry, Rz, Tx, Ty, Tz, s) from ED50 UTM (zone 32U) to ETRS89 and/or WGS84. The best match I could find is here: ...
1
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1answer
216 views

Why are the areas covered by 2 Universal Polar Stereographic (UPS) coordinate different?

According to http://en.wikipedia.org/wiki/Universal_Polar_Stereographic_coordinate_system. the area covering Arctic is less than Antarctic. Any reasons for it? It is due to the shape of the lands?
0
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2answers
312 views

Mercator projection image data

I'm trying to create a map which I can place points on within my application I found some mecator jpg images but in order to accurately place points I need to convert the lat/long to pixels so that ...
2
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1answer
154 views

Determining the transformation between a satellite image and long/lat

I'm trying to overlay some data onto a satellite image of the UK. The image is a hi-resolution version of the image below (originally from dundee university): ...
4
votes
2answers
4k views

Error 000735: Input Dataset or Feature Class: Value is required

I am a true novice when it comes to ArcGIS and computer programs like this one. Am taking a class and cannot get the Project function to work under the tool box. The path I used was ArcTool box --> ...
0
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1answer
218 views

Projection - Some of my data are in odd position [closed]

Some of my data has this position lon: 181 / lat: 91 So when I try to draw them on the Google map: var geographic = new OpenLayers.Projection("EPSG:4326"); var mercator = new ...
3
votes
1answer
139 views

How to test if two GDAL datasets are in the same projection?

I'm attemping to write a funciton to test if a list of datasets are in the same projection. Naively, I thought I could test the text of WKTs, but that does not work in the following case: ...
1
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2answers
759 views

Why is Format of output data grayed out on Save As dialog for Rectify?

I started georeferencing and I could not save my new "rectify" file, I don't know if is because of the raster or I did something wrong. Then I find out that my control layer is not accurate, it ...
1
vote
1answer
362 views

PROJ.4 custom projection that is Transverse Mercator with Affine post-process

I am trying to define some of my local TMAF grids in PROJ.4 so I can reproject points between the local grid and MGA95 and/or WGS84. For these grids I have the MapInfo CoordSys clause which defines a ...
3
votes
2answers
1k views

Display two layers with OpenLayers at once

How can i display two layers with diferent projections at once? For example i have layer with EPSG:70076 and OSM layer.
3
votes
1answer
1k views

Export to new projection in QGIS 1.8

I would like to use QGIS to convert a CSV file from UTM to lat/long. I imported the CSV file with the "Add Delimited Text Layer" plugin. This works fine, the data looks like it is projected properly ...
2
votes
1answer
599 views

Area calculation: Albers Equal Area vs Pseudo Mercator

I have a question concerning area calculations in South-East Asia for West-East range that goes from India to Eastern Malaysia and a North-South range from Northern India to Indonesia (xMin,yMin ...
3
votes
1answer
1k views

getting the specified geographic transformation, or at least the GCS, of a data frame

First, the TLDR digest: I'm getting a bogus value from dataFrame.geographicTransformations on some machines; how do I get the correct value as shown in the properties dialog? and/or Given a spatial ...
3
votes
1answer
2k views

ArcGIS 10.0/10.1 - arcpy - automate projection tool with different datum or projection

I am getting stuck with a task that is slightly different from the posts I found so far on this same website. Assumption: all layers have a defined coordinate system Problem: I would like to ...
26
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2answers
19k views

What's the difference between EPSG:4326 and EPSG:900913?

I am a bit confused on EPSG:4326 and EPSG:900913. I thought that they were both same. Though as I am placing my features over GMaps, which is EPSG:4326, I need to define the srsname of the WFS layer ...
2
votes
1answer
319 views

Problems with NAD27 projection in QGIS

I have some data that is in NAD27, but I am having a hard time displaying it in QGIS. I think that the problem is with the CRS. I cannot seem to find the correct NAD27 option. The closest one seems ...
0
votes
1answer
329 views

How can I find and fix broken raster metadata using QGIS?

I have a raster (TIFF) hillshade image that I would like to use in a mapping project. However, I'm having a hard time lining it up properly in QGIS. Through a series of investigations, I have ...
6
votes
1answer
134 views

Is there a name for map projections that produce two disks?

I've seen lots of world maps in the shape of two disks that touch, each one a separate projection of one hemisphere onto a disk -- usually the Western Hemisphere and the Eastern Hemisphere -- so ...
0
votes
1answer
426 views

How do I add a Corel Draw map as .dxf file to QGIS and how do I georeference it?

I have a vector data map of Poland, which I exported from Corel Draw. I can display the map in QGIS. At first the boundaries and subdivisions are only displayed as lines, after saving the data as ...
1
vote
0answers
148 views

Converting altitude in feet to pixels on a mercator map image

I know the question might seem farfetched given that the map is 2d. But I essentially want to project items-aircraft-above the map and I would like their altitude to be vaguely 'realistic' in terms of ...
0
votes
1answer
767 views

Which area measurement to trust? - The same polygon in GoogleEarth v. ArcGIS [duplicate]

Possible Duplicate: What is the most accurate coordinate system for calculating areas of polygons? I'm currently involved in comparing the "official metropolitan" areas of several cities ...
1
vote
1answer
121 views

Python error when running SpatiaLite with OSGB(27700)

I have a project open in QGIS and am trying to import an Ordnance Survey Address Point layer into SpatiaLite. I have recently installed the Qspatialite plugin. I open SpatiaLite in the DB Manager ...
4
votes
2answers
416 views

How do I Capture GDAL projection and create matching output (OGR or GDAL) shape files?

Working in C++, using GDAL and OGR: Depending on what the user has supplied for image input, I need to output point (or other) shape files in the same projection as the input raster images. The ...
6
votes
1answer
643 views

Coordinate system in aerial imagery

I am calculating WGS84 coordinates of points in an aerial image, given the WGS84 coordinates of the center of the image and the ground distance width and height (calculated from altitude and lens ...
2
votes
2answers
260 views

Why are the output point shapefile PRJ files empty?

I have tried evry thing I could find (using C++) to create a new .prj file for an output point shape file using OGR. While I get no compilation or execution errors and ArcMap accepts the file as a ...
2
votes
2answers
452 views

How to avoid exceeding latitude and longitude limits, when importing a .csv file?

I am currently working with a project with "on the fly"-projection (WGS 84 / UTM zone 32U). Now I want to import a csv. file with points, which have a longitude and latitude using the "Add Delimited ...
2
votes
0answers
366 views

Mapserver+openlayers: displaying a shapefile with Cylindrical Equal Area (Lambert) projection

I have some shapefiles in "World Cylindrical Equal Area (Lambert) projection". The .prj reads: PROJCS["World_Cylindrical_Equal_Area",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_ ...
3
votes
1answer
101 views

Projectionless shapefile with unknown source

I have a bunch of maps that are output from a land use model in .asc format, but none have a projection file associated. The person who originally ran the LU model is long gone, so I don't have access ...
2
votes
2answers
2k views

Howto change OpenLayers BBOX request projection?

My map uses EPSG:900913 projection on the map. All coördinates in the database are stored in the 'normal' google format / GPS coordinates (WGS84). For instance, if you save a new location..Before I ...