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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9
votes
2answers
751 views

What happens to feature class when importing to feature dataset?

I am creating a model that needs to ensure that all input datasets end up in the same coordinate system (among other things). I was originally going to batch project all of the datasets whether they ...
9
votes
2answers
3k views

Measuring distance in spherical Mercator vs zoned UTM

I've got points in WGS84 lat/long and I'd like to measure "small" (less than say 5km) distances between them. I can use the haversine formula from http://www.movable-type.co.uk/scripts/latlong.html ...
7
votes
2answers
689 views

Is there a standard for the specification of .prj files?

We use shape files for data exchange. I've looked at the .prj files: different programs produce different prj files. Is there a standard how the parameters must be specified in a prj file? AFAIK the ...
7
votes
2answers
783 views

How to Georeference Photos With No Spatial Reference?

I have about 100-200 field ground shot photos I would like to overlay in ArcGIS 10 that have no spatial information which I need to somehow develop using a photogrammetric formula. The camera was ...
7
votes
2answers
6k views

How do I convert affine coordinates to lat/lng?

I am extremely new to GIS. I'm using gdal to read in a landuse/landcover map and I need to pick out the lat/lng of certain land cover types to index into a different dataset which is expressed only ...
5
votes
2answers
1k views

Does anyone know the proj4 Coordinte Reference System command line for Rectangular Polyconic Gores?

I am a GIS beginner using QGIS 1.8.0 I am trying to transform a world map from the standard WGS84 Coordinate Projection System to a set of rectangular polyconic gores, with a gore count of 12. ...
5
votes
1answer
2k views

MGRS in OpenLayers

I am trying to view the Military Grid Reference System coordinates in Openlayers through the MousePosition control. Is there an easy way to accomplish this just through Javascript? I am looking at the ...
5
votes
2answers
850 views

Quick way to determine if facing a given lat/lon pair with a heading

I'm looking for a fast way, preferably without trigonometric operations (just multiply, divide, add, sqrt and subtract) to determine if a point is visible. E.g. say I am facing 0 degrees N, I am at ...
4
votes
1answer
422 views

How to properly open an ASTER data?

Yesterday i downloaded an Aster L1B image from USGS's website. If i load it in QGIS, it doesn't get displayed properly(location wise). Even after i've enabled "On the fly" option, it's not reading the ...
4
votes
0answers
136 views

What projection system is used in China which is aligned with WGS84 [closed]

I have some GPS tracks in Beijing. I want to project it and convert the lat long degree values in meters for calculation in euclidian space. I was wondering what is the most suitable coordinate and ...
4
votes
2answers
2k 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 ...
4
votes
1answer
5k views

Converting geographic coordinate system in R

I have points in geographic coordinate system and I wanted to convert them to swiss grid (CH1903+). Sample data: id lon lat 2 7.173500 45.86880 3 7.172540 45.86887 4 7.171636 ...
4
votes
2answers
748 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 ...
4
votes
2answers
1k views

How To Use Tiled Map Services with Different Spatial References in ArcGIS API for JavaScript?

I have the following code fragment in an esri page to try and change basemaps, the following code works, unless the next basemap layer uses a different spatialreference. if (baseMap) ...
4
votes
4answers
11k 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 ...
4
votes
2answers
3k views

ogr2ogr srs options: where is the well known definition determined?

In the ogr2ogr documentation it says that when using -a_srs srs_def: Srs_def can be a full WKT definition (hard to escape properly), or a well known definition (ie. EPSG:4326) or a file with a WKT ...
3
votes
1answer
129 views

Rhombus shaped pixels when viewing an image referenced in WGS84

Following the Question What is the projection of WGS84 in GIS software?, in the comments section of the answer http://gis.stackexchange.com/a/73578/5256, Jake very well explains that Because the ...
2
votes
1answer
284 views

Programmatically Select a CRS in QGIS 2.4 using Python

When you run the following Python code in the Python Console of QGIS 2.4, uri = "file:///C:/data.csv?type=csv&xField=lng&yField=lat&spatialIndex=no&subsetIndex=no&watchFile=no" ...
2
votes
2answers
774 views

How to use the coordinate system in arcgis 10?

I have a favor to ask. I have a few layers. The layers have been made by a different company. So how do I combine them all together so that they have the same coordinate systems? If there are any ...
2
votes
1answer
590 views

PostGIS: ST_Transform function conversion problem

I'm inserting map data from a GML file with srid EPSG:27700 into a PostGIS database table with srid EPSG:4326. I'm using the ST_Transform function as in this snippet: ...
2
votes
1answer
680 views

How to speed up this simple MySQL points in the box query

MySQL doesn't have nearest neighbor search so. So I try to come up with a "distance" that's reasonable so the number of returned query is around 20-200. That way innodb doesn't have to compute ...
2
votes
2answers
536 views

What does 1:10m mean related to map resolution?

On Natural Earth they offer maps at various resolutions. What does 1:10,000,000 mean? Does it translate to the number of points per square meter or mile?
2
votes
5answers
2k views

Convert geographic coordinates to UTM zone 29N with Javascript

I have an issue converting lat longs to UTM with the ArcGIS javscript API. Lets say that I have a map, based on the UTM zone 29N, also known as WKID 32629. I have a known set of coordinates from a ...
1
vote
0answers
39 views

Query all Object within n kilometer Radius with Hibernate Spatial?

I use hibernate spatial attach a geolocation to a car. My card domain class looks like this: import com.vividsolutions.jts.geom.Point class Card { String name Point location } My program is ...
1
vote
1answer
399 views

How do I create an index layer for multiple maps?

I am trying to create an index layer of just the area within the Orange lines. I am having difficulty creating this layer due to it not being a simple box area. The goal is to create a index layer, ...
0
votes
2answers
157 views

Calculate length of line across zones with at least m accuracy

I have created lines between multiple points that are across MGA 54 and 55S (EPSG 28355). I am trying to calculate the distance between points but different methods give different answers (~1km ...
0
votes
1answer
781 views

How to calculate the UTM-Latitude-band?

I have to convert a coordinate from UTM to MGRS. I think I have the most of it covered, but I have some difficulties to calculate the correct Latitude-band. How can I decide which band the coordinate ...
23
votes
3answers
3k views

What was the rationale for the non-standard UTM zones near Norway?

UTM zones 30V, 31V, 32V, 31X, 33X, 35X, and 37X do not line up with the rest of the UTM zone grid. Why was this allowed? According to Wikipedia, UTM was developed by the U.S. Army Corps of ...
8
votes
1answer
4k views

getExtent() in OpenLayers returns strange values

I'm trying to get the bounding box of the map area displayed by OpenLayers. I tried to use map.getExtent() because it should be exactly what I need, but the returned values are "strange": For ...
7
votes
3answers
1k views

Is there a name for 0,0?

Is there a name for the latitude/longitude pair 0,0? On a graph, (0,0) is referred to as the "origin" but I'm not sure if that term also applies to the location 0,0 in cartography.
6
votes
2answers
316 views

QGIS area calculation differs when on the fly CRS transformation enabled

When I open QGIS, add the layer, and calculate the areas of the shapefile via field calculator I get a different area than when I open QGIS and check "Enable on the fly CRS transformation" and ...
6
votes
2answers
684 views

Identify what projection this Australian map uses?

Im looking to put this map into google maps as custom tiles, but i now learn what projection is and that this map does not use the same format as google's default. You can create custom projections i ...
6
votes
2answers
2k views

Why do my Shapefiles not align correctly?

First: I'll summarize what I understand so far so please confirm or correct me. When On-the-Fly is selected a layer is re-projected from that of the layer's CRS to that of the project CRS, IF ...
5
votes
1answer
1k views

How do I find the intersections of 2 circles on earths surface?

I have the circles' center in lat & long, as well as the radius in meters. How do I find the circles intersections? Edit: EXAMPLE: Circle 1: Center on Earth's surface (43.564627,-116.220524) ...
5
votes
7answers
1k views

Problem with Swiss coordinate system overlay in WMS

I have administrative boundaries data for communities in Switzerland from SwissTopo. Original data came in shape files with 'Bessel 1841 Hotine Oblique Mercator Azimuth Natural Origin' projection. ...
4
votes
0answers
301 views

Can GeoTools parse GML CRS definitions?

A kind of branching of this question. Soon I will need to handle GML Coordinate Reference Sysyem definitions in a Java servlet. Links: GML OGC reference. Concrete example. I know that GeoTools ...
4
votes
2answers
475 views

How to efficiently project datasets of varying coordinate systems into one coordinate system?

I am working on streamlining data processing at my organization. Currently we are using various large-scale Models that we will gradually bring into Python. The gist of our data processing is as ...
4
votes
3answers
591 views

Defining the appropriate Projected Coordinate System

I am a beginner at ArcGIS and have a technical question. I need to assign a projected coordinate system to my boundary/polygon data in order to calculate square miles. There are many to choose from. ...
3
votes
1answer
86 views

USA Contiguous Albers Equal Area Conic to miles

My data is in USA Contiguous Albers Equal Area Conic projection. How can I convert the USA Contiguous Albers Equal Area Conic projection to miles?
3
votes
2answers
159 views

methods for converting coordinate datum and format in python?

Related to an earlier Q&A of Missing grid shift files for cs2cs.exe? ... what are the various methods to convert coordinate datum and format in python? (Windows Vista, python 3.4) For example, ...
3
votes
2answers
69 views

Digital Elevation Model and Shapefile not aligned in openWind

I have a digital elevation model and a shapefile containing point features for the location of wind turbines. These two layers appear to be aligned in QGIS but when I open them in openWind, they are ...
3
votes
3answers
5k views

Converting from an x-y coordinate system to latitude/longitude

I'm building an indoor wifi-based tracking system that can calculate the position of a device in meters relative to the sensors distributed throughout the building. So far I've gotten to the point ...
3
votes
2answers
1k views

Where is list of Geographic Transformations in ArcGIS, and their areas of applicability?

I have some data in Provisional South American Datum 1956, and I need to project it to Web Mercator with WGS84 as the datum. When I use the project tool in ArcGIS desktop, it requires a Geographic ...
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
424 views

How to programmatically determine whether a spatial reference factory code is valid?

I am using the following code segment to create a spatial reference. spatialReferance = arcpy.SpatialReference() spatialReferance.factoryCode = spatialReferanceFactoryCode ...
3
votes
1answer
657 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 ...
3
votes
2answers
429 views

How do you change the prime meridian of a map?

I am working with the Natural Earth world map as a SHP file, but when I try to change the prime meridian (PRIMEM) of the coordinate system ...
3
votes
1answer
3k views

How to get the coordinate system from a PostGIS database?

My question is probably amazinlgy stupid, but I can't find the answer myself. I would like to extract from a database the latitude and longitude of points. For now, I'm getting x(the_geom) and ...
3
votes
1answer
625 views

Arcobjects: Is my spatial reference Geographic or Projected?

I have the user select a coordinate system with the Spatial Reference Dialog. Is there a simple way to determine if the resulting spatial reference is a Projected or Geographic CS? I would of ...
3
votes
1answer
553 views

Why are the formats of these coordinates different?

I'm really sorry if this is a silly question (and I'm sure it is) but I have tried searching but I am a complete newbie to coordinates and maps and I don't know what I'm looking for so am not finding ...