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

learn more… | top users | synonyms (1)

1
vote
0answers
346 views

Reprojecting GeoTIFFs to WGS84/UTM

I'm using libgeotiff and proj4 to read and (try to!) process GeoTIFFs. After reading the file, I want to get the corner coordinates in WGS84/UTM - but there are so many functions and parameters to try ...
2
votes
1answer
114 views

Find projection from dataset

I have a dataset that I have pulled from a MaxSea 3d database. I am trying to figure out what projection is used, so I can transform and use the data. I have tried following this guide ...
0
votes
0answers
71 views

Changing projection does not change map extent

I have a shape file with a UTM projection. I want to save the data to a new shape file with a lat/long projection for a mapping system that only can deal with lat/long projections. I open the UTM ...
2
votes
1answer
199 views

Does the Load Data function in ArcCatalog automatically re-project the data?

If I have a feature class within a dataset in one coordinate system and using the Load Data function, load that data into a feature class of a different dataset that's in a different coordinate system ...
0
votes
1answer
163 views

Using the projection of a layer variable to project another in Model Builder in ArcGIS

So in model builder I would like to have one input feature class projected to match the projection of another layer (a raster layer) that is a variable in the model. Can anyone help me achieve this?
1
vote
1answer
397 views

Long range Trilateration from 3 lat, long, range

I've been looking at the following solution to a similar problem Trilateration using 3 latitude and longitude points, and 3 distances However with my problem the 3 points are spread over a large ...
2
votes
1answer
939 views

How to understand GeoTIFF tags?

I'm trying to understand GeoTIFF info, but not getting far. For instance, using listgeo with one file I can get this output: Geotiff_Information: Version: 1 Key_Revision: 1.0 ...
1
vote
0answers
139 views

Trying to convert to EPSG:27700 (Ordnance Survey) projection, unable to do so

I'm trying to code an interface that allows a user to draw a vector shape on openstreetmap, which is then converted to a WKT string, processed by the server and sent of as a WFS query to emapsite ...
1
vote
1answer
865 views

OpenLayers TMS limit zoom and extent

I have a custom map which I get from a mbtiles file with the bounds -13,25,49,60 and zoom from 4 to 10.The display div is dynamic, I mean that it depends on window size and the extent restriction ...
0
votes
1answer
76 views

How to retrieve PROJECTION value for a map?

I am trying to read the Projection from Geotiff/shape file, using gdal 1.9.0 by the following command in the command line... gdalinfo.exe -proj4 map-path but its retuning empty string for ...
1
vote
1answer
446 views

Which CRS fits “Lambert Conformal Conic Projection, Standard Parallels 46.40 and 49.20”?

I am trying to georeference a VFR chart in qgis and I can't figure out which CRS to use. Map projection - Lambert Conformal Conic Projection, Standard Parallels 46.40 and 49.20. Any ideas which ...
1
vote
1answer
245 views

How do you make a function for changing projection with proj4js in Openlayers?

I have included Proj4js in OpenLayers. I would like to create a function (so I can use a make a button). To change the projection of my map. I have included in javascript Proj4js.defs["EPSG:54008"] ...
1
vote
1answer
412 views

Python GDAL/OGR: WGS84 & meters units

I'm dealing with shapefiles projected in: GEOGCS["GCS_WGS_1984", DATUM["WGS_1984", SPHEROID["WGS_84",6378137,298.257223563]], PRIMEM["Greenwich",0], ...
1
vote
2answers
80 views

Error reported when trying to import prj for data points in New Brunswick Canada into QGIS

I have data points recorded with a Trimble GIS. The projection is New Brunswick Sterographic Double Projection, which as near as I can find via a Google search is EPSG:2953. However, when I try to ...
8
votes
3answers
1k views

Distance measurements across UTM zones: use geographic or planar approaches?

I have a survey grid spread across 3 UTM zones (36N, 36S, 37S). I want to find the nearest (or shortest) distances of the centroids of these grids to roads and various points between. It seems like ...
2
votes
2answers
108 views

How to reproject all featureclasses in a database to another database?

I am very new to arcpy and have ArcGIS 10.0 I would like to make a script where I would only have to change two variables in a script (database_input and database_output) so that I can reproject all ...
1
vote
1answer
1k views

How to I create a .prj file with the following projection parameters?

I have received shape files that are missing .prj files. The documentation for the shape files describes the projection system as Lambert Conformal Conic and provides the following "Projection ...
1
vote
1answer
933 views

Python GDAL: degrees to meters without reprojecting

I am trying to get senseful results in my Python script. I want to measure distance between features in a shapefile. I'm working with the SRS: GCS_WGS_1984, so my units are in degrees. But for the ...
0
votes
1answer
247 views

How can I clean up this OpenLayers code by correctly doing a transform or projection, for an array of features?

I have some features I've created via some Kml data. Now, to display these features on a Google Map, I need to project them from 'EPSG:4326' to 'EPSG:3857'. This works great. Now, i need to convert ...
1
vote
1answer
575 views

TileStache + OpenLayers TMS - Tiles are rendered disorderly

I newly turned to TileStache to render Mapnik tiles because of the caching option. Before, I was using Mapnik python bindings only and it was working perfectly. Now that I use TileStache, the tiles ...
2
votes
2answers
1k views

OGR Projection transformation error

I am trying to convert shapefile that was created by FME in EPSG:900913 to EPSG:3857 (I know its the same definition) with OGR in a script. datasource = ogr.Open(os.path.join(dirname,shapefileName)) ...
1
vote
1answer
2k views

How to transform World data from EPSG 4326 to EPSG 3857

I have tryed different opensource tools to transform a world data shapefile from 4326 to 3857 but I always have an error. Im not sure, but is it because of Antartica? I have tryed with GDAL and QGIS ...
0
votes
2answers
633 views

How to scale/reduce my polygon without changing the central lat & long?

I am writing a VBA code to resize my polygon, I get a input as vector points(Shape file). The code below resizes it as according to my scale factor but my central latitude and longitude are also ...
0
votes
0answers
188 views

How to find out what projection my data is using?

I have a set of data that I created from gps locations of images. The locations are in decimal. I don't know what projection was used when the data was captured. I used QGIS to display the data with a ...
1
vote
1answer
276 views

Pseudo Mercator error?

I'm mapping on QGIS, I have a vector layer and his CRS is on EPSG:4326 - WGS 84, but also I wanted to put a satellite image, so when I do it, the image use WGS 84 / Pseudo Mercator. The problem is, ...
0
votes
0answers
100 views

need info on GeoTIFF projection keys

I am a programmer (not a cartographer!!) developing an application which needs to read and write GeoTIFF files. I have a number of questions about those GeoTIFF keys which are related to projections. ...
1
vote
1answer
53 views

Editor and projections ArcGIS

When opening an edit session Arc is telling me that some of my shape files' coordinate systems do not match the data frame. Here is the data frame coordinate system: Stereo_70 Projection: ...
2
votes
2answers
105 views

Digitized Shapefile manually using wrong projection: how to fix it?

I have a raster in correct projection. I used shapefiles, and marked objects (manually), but I found out that my vector layers have different projection, so they have different size and position. Is ...
1
vote
4answers
641 views

What projection to use in ArcMap for a map that extends over Wgs84 Utm31 and 32

Please i have a Wgs84 Utm map that extends over 2 utm zones(31N and 32N). Using either of them distorts my map and ArcGIs allows you to choose only one projection per map. Please what can i do? Thank ...
2
votes
2answers
190 views

Mapping elements in a warehouse

I am new to GIS. For a small project I want to map elements in a warehouse and want to find the location of the elements later (e.g. nails are located at x,y). Now I am wondering what kind of ...
1
vote
1answer
531 views

How to create a Winkel-Tripel map of countries with different colors?

I need a good quality rasterized world map, Winkel-Tripel projection, in which all countries have different (random?) colors. No borders, text, grid or anything else on the map. Is GIS the right way ...
2
votes
1answer
216 views

If I've given two different layers the same CRS, why won't they overlay one another?

I have a "towns" and "state" shapefile for Massachusetts as two separate vector layers in QGIS. I've set the project coordinate system to WGS 84 at the bottom of the screen (next to the "coordinate" ...
0
votes
1answer
328 views

Why does map display like it is in Isometric when everything is in EPSG:4326?

I'm beginning with Geoserver and try to display a map of my country (Belgium) is an openlayer map (embedded into a MapPanel object). I've downloaded the municipalities limits from gadm.org and copied ...
1
vote
1answer
78 views

Some terms related to coordinate

I was googling coordinate related information all the day. Now I am confused with some concepts and terms. I hope some one can help me to make it clear. Geographic coordinate system Geographic ...
2
votes
1answer
72 views

When is a projected length calculated via a pythagorean distance more accurate than an ellipsoidal length?

I'm using spatialite 3.0.1 with the following test data (in EPSG: 4326): Name astext(geometry) ---------- -------------------- Belitsa POINT(23.563 41.947) Malko Tarn POINT(27.533 ...
0
votes
0answers
41 views

what is the difference between the Geographic coordinate, transformed coordinate and screen coordinate [duplicate]

What is the difference between the Geographic coordinate, transformed coordinate(projected) ,cartesian coordinate, and screen coordinate? Is there a live example? And what is the association between ...
2
votes
1answer
140 views

Wrong object size after projecting spatial data from one coordinate system to another

I am having problems reprojecting items in ArcMap 10.1 from British National Grid To WGS84. (WKID: 27700 Authority: EPSG to WKID: 102100 Authority: ESRI) All Polygon Layers I project [I use Project ...
3
votes
3answers
5k views

Which CRS to use for Google Maps?

I am trying to map a Shapefile (download) onto a Google Map using the Javascript API. The Shapefile describes the boundaries of NYC School Districts. The file's projection was Lambert Conformal ...
1
vote
2answers
100 views

Is it possible to have another CRS in the status bar than used for the map?

I am new to QGIS. When I use OSM or Google Maps as a basemap via Open Layer Plugin, the map should be projected as EPSG: 900913. However, the Coordinates shown in the status bar are useless for me, ...
0
votes
2answers
787 views

Tile script (Mapnik) with OpenLayers - Problem with projection (900913)

I use Mapnik python bindings in a geodjango application to render tiles in openlayers with datasource stored in postGIS in 900913 projection. The feature seems to be rendered correctly in the ...
2
votes
1answer
535 views

Blank MapServer WMS image at low zoom levels in OpenLayers

I have an OpenLayers map using OSM as the baselayer with several layers coming from MapServer via WMS. The OL map is in EPSG:3857 and my mapfile (and shapefiles) are in EPSG:4326. In my mapfile I ...
1
vote
1answer
545 views

how to make the translation between latitude/longitude and screen pixels

The earth is three dimension object while our screen is two-dimension. So when we use the gis software to display the geographic data, how do they handle the translation between latitude/longitude ...
1
vote
0answers
619 views

Using gdal to convert from UTM to equidistant lat/lon

I am getting rather confused with converting a UTM gridded dataset into a equidistant/rectangular latlon gridded dataset. Can anybody help me? I have a UTM set with the following projection: ...
1
vote
1answer
520 views

Problem Overlaying layers in OpenLayers

I have a html page with 2 WMS layers. The first is one Base Layer , & the second is my personal WMS feature. I load it from Geoserver. The problem when I add the 2 layers I do not have the ...
3
votes
1answer
46 views

Does IDistanceOP.EucDistanceFull require a projected coordinate system?

I have designed an implementation of ArcObjects' IDistanceOP.EucDistanceFull. It takes its input as a feature class and converts it to a GeoDataset with which EucDistanceFull can work with. It works ...
0
votes
1answer
318 views

Why do points shift when reprojected from WGS84 to a state plane coordinate? [closed]

We have a Trimble unit we use to collect equipment. We collect the data in WGS84 and differentially correct it and then reproject it to a state plan coordinate system. The points always shift the ...
0
votes
0answers
20 views

De facto QGIS projection for EPSG4326 / 'unprojected' reference systems? [duplicate]

This is my understanding of projections/datums: To get a map of the earth on a plane you need to project the 3 dimensional earth by 'wrapping' a plane around it in the way that suits you (according ...
2
votes
1answer
164 views

Do FeatureLayers reproject their features to adapt them to the map projection?

I'm working with the ArcGIS Flex API. For example, ArcGISDynamicMapLayers do reproject their data in order to make it in the same projection as the map. Do FeatureLayers have the same behaviour?
0
votes
0answers
31 views

QGIS: Unable to project raster layers correctly on a Toshiba Tecra 64# Win7

I know how to project a raster, I can do it on other machines. On this particular machine the raster loads but are no where near the correct position as if the datum is on another planet.
11
votes
1answer
365 views

Assign projection to a satellite image

Today I stumbled upon a picture taken from the ISS looking down Europe and it is really beautiful. So, I started thinking I could add more to the picture. Like world borders, cities, road network, ...