# Tagged Questions

42 views

### How can i figure out to convert this points to latlong?

I got below data in sql server, Learned that data is collected under zone IIIa considering Lambert Conformal conic projection in India. The data is generated from Spatial Cadastre Software. Also ...
59 views

### Historical maps as cylindrical projections

Objective: I want to overlay old, historical maps on top of Google Maps. According to Wikipedia, Google Maps uses a variant of the Mercator projection, a close relative of cylindrical projections. ...
420 views

### Postgis | Problems Reprojecting a Point from UTM ED50 to GEOGRAPHIC ETRS89

I've got a POINTS PostGIS table in the 23030 (ED50 UTM 30N) SRID. I'm having a lot of problems trying to reproject those points from ED50 UTM coordinate system to ETRS89 Geographic (lat/long) ...
686 views

### Formula/ calculation for ESRI map coordinate conversion (meter to decimal degrees)

I'm new to ESRI mapping. I have a set of points in ESRI, with x, y, z coordinates, which I believe is in meters. I am now writing an Android program, and I do not want to depend on ESRI, thus I would ...
131 views

### Comparing features in GIS interface with Google Maps/Bing Basemaps - Which Co-ordinate system to use?

I want to compare some Geographic features in my data with Google maps in ArcGIS platform using a third party application. But I prefer the output to be in Local UTM cordinates. What is the best ...
6k views

### What is the difference between EPSG:900913 and EPSG:3857?

I'm using the QGIS google layers plugin to digitize a parcel as a shapefile. Later I want to import it to PostGIS. I know that google maps use a special 'google mercator' projection. What is the ...
299 views

### How do I use Proj4js or other technique to make custom map projections with google.maps.Projection?

I'm using Google's Projection class to try to convert my map projection from the default spherical mercator to something like Lambert Conformal Conic. I was previously adapting the code from this ...
914 views

### How to unproject coordinates on a Google map with Openlayers?

Below is my code and a pic. When I finish making my circle on a Google map with Openlayers, I get the following coordinates but I want coordinates like E.G: bottom: -27.762124575762 left: ...
8k views

### Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { ...
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 ...
244 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! ...