Tagged Questions

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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10
votes
10answers
7k views

Batch convert lat longs to UTM?

I've got a .csv file that contains a long list of latitude and longitude points. Is there an efficient way to batch convert the list into a projected UTM coordinate system? Thanks.
33
votes
10answers
10k views

Identifying Coordinate System of Shapefile when Unknown?

I have a Shapefile but its coordinate system is Unknown, and there is no *.prj file. How I can identify it now? Are there any tools that could help?
4
votes
5answers
1k views

Converting LatLng coordinates to point shapefile

I have more than 50,000 LatLng coordinates defined under SWREFF99 1800 projection. I want to know, is it possible to convert these coordinates into a point shapefile ? if yes, then how can I do this ? ...
3
votes
2answers
2k 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 ...
0
votes
1answer
396 views

How to transform a DEM to a cartesian coordinate system?

I am using the script r.inund.fluv. I run the script with all the required parameters and it produced a lot or errors. I emailed the author of the script and he said that "I think you are not ...
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 ...
5
votes
1answer
1k views

Spatial Reference is null in ESRI Silverlight Map

I am using ESRI's Silverlight API to display a map with one dynamic layer. Occasionally (not always), when that layer is initialized, the SpatialReference attribute will be null. I'm not sure why ...
2
votes
3answers
832 views

extract lat/long from screen when using British National Grid projection

Using ArcGIS 10, is it possible to click anywhere on the map (projected to British National Grid), but return the coordinates in WGS84 lat long? Alternatively, when will Streetview work with OS ...
2
votes
1answer
304 views

Two rasters created from the same polygon have different extents?

My problem is that i am trying to export some rasters to Rockworks so that i can create a sand layer from them. Rockworks requires the grid files i use to have the exact same XY co-ordinates. So i ...
34
votes
3answers
8k views

LatLon or LonLat, what's the “right” way to display coordinates and inputs?

I'm trying to get a sense if this is an issue for others or every input/output should be labeled so user is not confused and just go with it? I think almost everyone pronounces it as "LatLon". Who ...
8
votes
3answers
9k views

Coordinate System Transformation in ArcMap

For the Data Frame Properties on a map in ArcMap, what is the difference between selecting a new coordinate system and using a Transformation?
8
votes
3answers
343 views

Global grid, which reference system to use?

I have seen a couple global studies using WGS84 as geographic reference, with the problem that the area of raster cells is not constant. Which reference system would you use for a global analysis in ...
20
votes
6answers
14k views

Defining projections for multiple shapefiles in ArcMap?

I have over 100 shape files that don't have .prj file and thus when I bring them into ArcMap 10 they show the coordinate system as unknown. I know all of the shape files coordinate system is GCS WGS ...
2
votes
2answers
456 views

Coordinate system in Map&Guide

One of my customers is evaluating transport planning software Map&Guide (http://www.mapandguide.com/) and what we require is to get the transport route data from their file to Garmin navigation ...
4
votes
1answer
2k views

Convert Gauss-Kruger to UTM

How to covert Gauss-Kruger coordinates to UTM coordinates with GeoTools java library? As I have figured out the location (zone, country) is important. I need the calculation for Slovenia.
6
votes
3answers
3k views

Writing world file when exporting TIFF using ArcPy Mapping?

According to documentation, the options are: Syntax ExportToTIFF (map_document, out_tiff, {data_frame}, {df_export_width}, {df_export_height}, {resolution}, {world_file}, {color_mode}, ...
5
votes
3answers
1k views

PHP MGRS Conversion Formula/Library

Currently, the formula I'm using to convert MGRS to Lat/Long and vice versa is giving me slightly different results than most other conversion utilities. It's usually between 10 to 30 feet off. This ...
3
votes
1answer
3k views

Lat/Lon/Alt to spherical or cartesian coordinates

On my previous question, it was advised I convert lat/lon/altitude to spherical or Cartesian coordinates. I'm not working near the poles and it would be safe to assume a spherical earth. What would be ...
5
votes
2answers
707 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 ...
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. ...
18
votes
5answers
4k views

How do you best deal with data that spreads across UTM Zones?

I have data that spreads across two UTM Zones GDA/MGA94 UTM Zone 55 and 56. I have layers such as a cadastre, roads, pipelines etc where I want to store measurements like lengths and areas in metres ...
4
votes
1answer
1k views

ArcSDE - Registering table with Geography spatial column fails with error -138 (SQL Server 2008)

I have a table of point features I am trying to register with ArcSDE (9.3.1 on SQL Server 2008) using the following command: sdelayer -o register -l ThirdPartyWellsSurface,Shape -e np -C OBJECTID,SDE ...
8
votes
5answers
2k views

What are the advantages / disadvantages of reporting location in decimal degrees versus degree min sec?

Many scientific articles report site location in units of degree/min/sec, but for analysis in with non-GIS software, it is easier to use decimal degrees. Is there a reason for degrees / min / sec to ...
2
votes
2answers
596 views

Custom Coordinate System

We have a number of custom local coordinate systems at work. I'm trying to create a well known text coordinate system for each of them however I'm stuck on how to define these systems they . Some ...
25
votes
3answers
22k views

What is the difference between WGS84 and EPSG4326?

What is the difference between WGS 84 and EPSG 4326? It seems like for a given dataset it might be both WGS 84 and EPSG 4326.
11
votes
7answers
378 views

Public reprojection services

Are there any free public services where I can send one point in a coordsystem and it returns the point reprojected in a specified coordinate system? I will not be doing many requests, for now it is ...
31
votes
3answers
36k views

Algorithm for offsetting a latitude/longitude by some amount of meters

I'm looking for an algorithm which when given a latitude and longitude pair and a vector translation in meters in Cartesian coordinates (x,y) would give me a new coordinate. Sort of like a reverse ...
4
votes
1answer
429 views

Equal Area SRID for Australia

This has been bothering me for some time so I figured I would put it out there. Does anyone know the SRID for an equal area projection that is suitable for the whole of Australia? I realize that I ...
44
votes
7answers
3k views

What strategies, criteria, or rules to use for selecting coordinate systems?

What strategies, criteria, or rules do you use for selecting coordinate systems for (a) storing, (b) analyzing, and (c) displaying GIS data? (I humbly offer my reply to a related question ...
11
votes
3answers
3k views

Official term for latitude longitude coordinate system?

May I know what is the correct specific term for latitude longitude coordinate system? With "Geographic Coordinate", it seems to be a general term for every other system?
20
votes
3answers
2k 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 ...
3
votes
2answers
439 views

Trying to load this map service from ArcServer.. its on our own system but its not working… or I don't have access

Can anyone see this? http://gis.co.frederick.va.us/ArcGIS/rest/services/TestSDEService/MapServer Spatial reference is.. var initExtent = new esri.geometry.Extent({ "xmin": ...
9
votes
3answers
6k views

How does ArcGIS compute the distance between two points with a non-equidistant projection?

This is a follow-up question to my previous one, Can you suggest some well-written introductory texts about coordinate system projections? Let's assume I'm working with the CH1903 map projection, ...
1
vote
1answer
99 views

How to reference vector based data to raster data that already has spatial reference in MAPublisher?

I have been able to load in raster data into MAPublisher and properly registered it, however I have been having trouble with a further step. I am trying to reference vector data that has no GCS or ...
5
votes
2answers
2k views

Is it possible to change spatial reference (and reproject) feature classes in-place, using ArcMap/GeoProcessing?

We have an Esri based system in production; a complicated data model with a large number of feature classes. We need to migrate the data to another spatial reference. The feature classes have class ...
5
votes
4answers
11k views

Convert latitude and longitude into northings and eastings

Hi I have the following UK postcode dy8 3xt and know that the latitude and longitude is:- 54.452772 -2.156082 I also know that the Eastings, Northings for the postcode is:- 389490 283880 ...