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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3
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1answer
347 views

Ogr2ogr projection problem- features are shifted 12 miles to the north?

I have discovered a problem related to the output of an ogr2ogr command line call. My resulting polygon features are 12 miles (.18 degrees) due north of where they should be, but the longitude is ...
1
vote
1answer
436 views

Issues with defining projection to that of the current root file

I am creating a shp file with the extent of all the raster file in a set of directories and it works fine when all the rasters are in the same projection but not when they switch around. So I want to ...
0
votes
1answer
1k views

QGIS and MapInfo Projections - EPSG 27700 (British National Grid)

I have some data in a PostGIS table with the projection EPSG 27700. If I export this data from QGIS (v1.8) to MapInfo TAB / MIF when I open the data in MapInfo it has a shift on it. Does anyone know ...
3
votes
2answers
469 views

Project twitter geo data into wgs 84 map

I'm currently working on displaying twitter geo data (currently just long/lat -> cartesian without any analysis). This is the world map (source: naturalearthdata): ...
5
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0answers
101 views

Is there a tool to retrieve the projection system used to create a shapefile when the prj file is missing? [duplicate]

Possible Duplicate: .shp with unknown coordinate system Are there any tools to help retrieving the projection system used to create a shapefile when there is no .prj file? Given that ...
2
votes
1answer
489 views

How to determine area of pixel in meters with GDAL and Python?

I have a raster loaded in Python using GDAL bindings. I'd like to be able to determine the area of a pixel in meters although I'm not confident that the projection is in meters. On this page I see a ...
7
votes
3answers
4k views

Why don't my Shapefiles and OSM data overlap in Quantum GIS?

So I'm pretty new to GIS, and I'm working on a mapping project using data for Vancouver, Canada. I want to combine Open Street Map data along with data provided by the City of Vancouver. But the City ...
1
vote
1answer
244 views

Lambert cylindrical projection support in PostGis

Does PostGis support Lambert cylindrical projection or is there a way to add support for it? I'm probably searching the wrong terms, but google isn't bringing up anything useful. Any help is ...
3
votes
1answer
550 views

How to generate a grid of horizontal equal-area rectangles in a Mercator projection?

I'm new to GIS so pardon my ignorance and bear with me. I'm generating a grid relative to a LonLat point. To make the cells all equal area, I'm creating it in 2163 projection. The problem is that when ...
4
votes
3answers
6k views

How do I include proj4js in openlayers?

in my Openlayers app, since the base map projection is not epsg900913 or 4326, I need to include proj4js in order to use geolocation feature. but i got such a error notice: GET ...
11
votes
4answers
2k views

How to reproject spatial data using free libraries?

How can I use free libraries to transform spatial data? For example, I want to change the projection of a Shapefile within the code of my C# web application. How do I do that?
3
votes
1answer
583 views

How to solve Projection Problem at client side

I want to discuss a scenario here to all. I have developed a Web mapping application in OpenLayers and GeoServer. The customer give us shapefiles with native projection SWREFF99_1330 (EPSG:3008). ...
1
vote
1answer
149 views

Get relative north aligned point 2163 (US Equal Area)

What I'm trying to do is create a grid where the y axis is north aligned. I have a origin Lat/Lon point which is the bottom left corner of the grid and each cell should be 100 by 100 meters. So I ...
1
vote
2answers
713 views

Can I project 3D DXF vertical cross section into a “plan view projection plane” for display in ArcMap?

Below is the lenghty explanation but simply put my question is: How can I project a 3D DXF file (vertical cross section) into a "plan view projection" for use in ArcMap? I am using Target (by ...
6
votes
1answer
2k views

Computing UTM Zone from lat/long point?

I am trying to convert a latlong point to UTM. To define UTM projection, I need to calculate zone for the point. I am trying to figure out the best way to do this. One way to do this would be ...
6
votes
4answers
9k views

How to reproject base layers in OpenLayers?

The issue is: I have vector/topo/image tiled maps for some places in north america which were published as ArcGIS Server REST service. These maps (A) are based in EPSG26912 projection. Now I wanna ...
0
votes
2answers
998 views

How would I convert this point to WKID 4326?

This is a point in Brewster, MA, USA. How would it be converted to WKID 4326? 324299.3348436486, 832511.5939650714
4
votes
2answers
2k views

How to “calculate” distance-to-ground of all 18 OSM zoom levels?

Assuming I'm building a 3D solution with the "world" being mapped to global geo-data supplied by OSM / Cloudmade... think http://www.webglearth.com but with completely different goals and use-cases. ...
3
votes
2answers
248 views

What projection is this in GDAL classification

I need to re-project a PNG from a given projection to the Google maps projection. I have a grid of the source projection, looks like a Mercator projection. What is the exact name of this projection in ...
2
votes
1answer
653 views

Rendering 3D timezones KML on a 2D map

I'm trying to render a KML layer (with timezones) in Google Maps API v3. The KML layer works fine in 3D (in Google Earth), but when I render it in 2D, the timezone lines that meet at the North Pole ...
40
votes
4answers
6k views

Why has Web Mercator (auxiliary sphere) become the web map standard?

I understand what the difference is between the Web Mercator projection and Web Mercator Auxiliary Sphere (WMAS). I also understand that both Google and Esri have adopted this projection as their ...
0
votes
2answers
274 views

Shp's will NOT line up (coordsys) - shps made using GPSeismic sotftware (client made shp's)

OK, I asked this previously but solved it on my own last time. Same project, but differant shp files. I recieved from a client shp files that were made in GPSeismic 2011. Upon recieving the shp ...
2
votes
1answer
86 views

Coords not aligning

The two shp files are not aligning like they should (note the img). The layer and the two shps all have the same coords - NAD_1983_StatePlane_North_Dakota_North_FIPS_3301_Feet The surface shp came ...
1
vote
2answers
567 views

Project WGS84 to Google using MapGuide and WKT

I'm having trouble projecting a simple WGS84 formatted layer over google maps. I can't find a good WKT "API" that not only shows parameters, but explains what each parameter is. The coordinate system ...
6
votes
1answer
730 views

SRID error in mapserver

I've created a network topology using QGIS, saved it as a shp, imported it into PostGIS using shp2pgsql and I'm now trying to output some of the geometry using mapserver. Unfortunately mapserver is ...
3
votes
0answers
1k views

Converting projected coordinates to google maps pixels

I have a single polygon in a local projection system. I would like to convert that polygon into an image that can be used as an overlay on google maps. I understand that it may be better to use ...
0
votes
1answer
441 views

How to point out a city from a map image of world with longitude and latitude?

have a map image 800px wide. How can I figure out a city. like New York has 40.75 latitude and -73.98 longitude. I have to pin a mark over this point. Before I have done with x_axis and y_axis which ...
2
votes
2answers
473 views

Error when setting projection of a tif file in QGIS. Any ideas to solve this? [closed]

I get this error when trying to define a projection for a tif file in QGIS: ERROR 1: Too many points (3249 out of 3249) failed to transform, unable to compute output bounds. How do i work this out? ...
1
vote
1answer
485 views

How to resize layer using .prj (WKT) projection? (Geographic Coordinate System)

Briefly: How to parametrize .prj WKT file so that I can perform 7 point tranformation (wiki). I know how false_easting and false_northing params work, but how can I adjust scale? I do not mean ...
2
votes
2answers
397 views

Shapefile CRS changed after exporting from QGIS. Are they equivalent?

I added a shapefile as a vector layer in qGIS 1.7 so that I could join in additional attribute data (not geodata) from another DBF file. The Shapefile that I added has this CRS (as far as I can tell ...
2
votes
4answers
4k views

Export to new projection in QGIS 1.7

Suppose I have layers A and B. I don't know their projections but by the looks of the map I know they are not the same. In QGIS 1.6 I would use one of my favorite features: Vector> Data ...
4
votes
4answers
599 views

Determine Projection

I was given a shapefile at work with the information that it is in Lambert Azimuth Equal Area (LAEA) projection (EPSG 9820). After some research on the web, I found out that EPSG 9820 is a generic ...
12
votes
1answer
560 views

How is a “conformal latitude” used in ellipsoidal stereographic projections?

At my work, I've been doing some maintenance on internal software that claims to implement a Stereographic projection whose formulas were copied from an old system a long time ago. From what I've ...
0
votes
2answers
257 views

How to realign misplaced GeoTiffs?

I have bought a few (30) GeoTiff maps from my country's Geo-department - South Africa. They all have a date in the filename and the newest one was created in 2004, I see one is dated 1977 - that old! ...
1
vote
1answer
350 views

Defining custom projection for moving all objects on X and Y coordinates

I have a map project wih layers in WGS1984 UTM projection. I also have a bunch of layers without .prj files. When I add it on top of my layers, it's placed with a huge offset on X and Y coordinates ...
3
votes
1answer
1k views

Mapserver, TMS, Scales zoom levels and how to deal with all of it

I have a whole bunch of data in my db that I need to draw at different zoom levels using Mapserver. Everything uses a 4326 SRID. My (custom) client, will fetch the data using 20 TMS zoom levels and ...
2
votes
2answers
2k views

Problem reprojecting data from personal geodatabase using QGIS

I have a dataset in the form of a personal geodatabase (mdb) and am interested in using certain feature classes for further processing. My problem is - I am using USGS data orthoimagery which comes ...
5
votes
1answer
286 views

Mapserver tiles - trouble with projection

I'm trying to render tiles with shp2img tool from Mapserver suite and my tiles aren't matching. Tiles are numbered like in openstreetmaps.org. This is an attempt to draw tile (level 1, x=1, y=0) which ...
1
vote
1answer
297 views

How to reproject a noaa bsb nautical chart?

I have some nautical charts in .BSB format. GDAL can read bsb and I successfully imported them to qgis. But I can't figure out what is the coordinate system they use. Does anyone has some experience ...
3
votes
1answer
795 views

How to provide transform information to openlayers on Image layer

I would like to include an overlay raster layer into my OpenLayers map. I've pre-transformed the image into the correct projection (EPSG:900913) and saved as a png using the gdal_translate command: ...
4
votes
1answer
238 views

Access is Denied error on ProjectEx call

I need to be able to convert a lat/long coordinate into a point coordinate and am having trouble getting my code to work. I created a test app isloating the code that is giving me problems. I'm ...
5
votes
6answers
871 views

Southern hemisphere projections for Landsat upsets GRASS

Hi All does anyone have the last word on why Landsat scenes don't project in the southern hemisphere. This causes no end of trouble in GRASS, less so in QGIS. What I mean is, take an original scene ...
1
vote
1answer
349 views

How to project the result of a QueryTask in ArcGIS Javascript API?

I have created a web map that displays point features based on a given date range. Our current projection is Oregon State Plane South. My boss wants me to change the map to use a Web Mercator ...
2
votes
1answer
926 views

Geowebcache does not displaying map tiles in EPSG:900913 from a remote WMS server

I connect Geowebcache to a remote WMS service through their Getcapability request by adding the url in geowebcache-servlet.xml document. Geowebcache demo page displays the list of wms layers from ...
8
votes
2answers
572 views

Why are there both square and rectangle world maps?

When i search for images of earth divides to longitude ans latitudes seems that the are 2 major types: is a perfect square and the latitudes in it are grow a different rate from the equator to up ...
3
votes
2answers
4k views

How to read projection information from .dwg file

I have got an Audocad .dwg file which is based on some location of sweden. But i dont know what is the internal projection of this file? how i get projection information from this .dwg file. Actually ...
4
votes
4answers
10k views

Getting shapefile in right projection using ArcGIS Desktop? [duplicate]

I have an older map that I didn't create. I'm just trying to get everything to line up on it, and having a hard time. The data frame is in NAD_1927_UTM_Zone_12N, as are the point shapefiles (derived ...
3
votes
1answer
730 views

How can I programmatically project the Z value of a z-aware feature point, using ArcObjects in .NET/C#?

I discovered the following code leaves the Z coordinate of featurePt untouched: // if not WGS84 project it if (!SpatialRefsEqual(featureSpatialRef, srWgs84)) { // featurePt here is a Z-Aware ...
-3
votes
4answers
717 views

Repository for .prj files

Do you know any repository where can i find .prj files? I am looking for local coordinate system: Warszawa 75 (Warsaw 75) I found myself this repository but the .prj which i found there seems to be ...
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 ...