Any of a set of two or more numbers used to determine the position of a point, line, curve, or plane in a space of a given dimension with respect to a system of lines or other fixed references.

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23
votes
3answers
1k views

Why do we use the terms “longitude” and “latitude” for a spherical body?

To specify a geographic coordinate we use the terms “longitude” and “latitude”. Far as I know, these terms derive from the Latin latitudo (= breadth) and longitudo (= length). In German we use the ...
18
votes
1answer
3k views

Is WGS84 itself a Coordinate Reference System?

I was wondering the difference between WGS84 and EPSG:4326 (see this). Can then WGS84 on its own be defined as a Coordinate Reference System? Or is it just a datum so that a Coordinate System must ...
18
votes
1answer
867 views

What is the most accurate coordinate system for calculating areas of polygons?

I have multiple polygons, all located offshore around the UK. I am trying to calculate the areas of these polygons in square kilometres, without splitting them by UTM zone. Is it possible to do this ...
13
votes
4answers
10k views

How do I create point features with exact (manually entered) coordinates?

How do I create point features with exact (manually entered) coordinates i Quantum GIS (QGIS)? I get precise gps coordinates from a survey team which I need to add to a point layer. What I want: -Add ...
11
votes
3answers
3k views

How to move vectors to specified coordinates in QGIS?

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000). How should I do it? Preferably using QGIS.
8
votes
3answers
5k views

How to generate random locations nearby my location?

I am trying to create random locations nearby my location. What i want is to create random latitude/longitude pairs inside a 200 meters circle surrounding my location. This is the formula i came up ...
8
votes
1answer
1k views

Computational most efficient way to convert Cartesian to Geodetic Coordinates

As far as I understand the literature there are several ways to convert a set of geoecentric cartesian coordinates to geodetic coordinates Bowring, 1976 Borkowski, 1989 Lin & Wang, 1995 Toms, ...
8
votes
3answers
509 views

Given a set of coordinates, how can I calculate the minimum bounds?

I have a set of coordinates in lon/lat. There are always at least 3 ordered coordinates that form a poly (if they were projected flat). How can I calculate the minimum bounds for these coordinates as ...
7
votes
2answers
441 views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
7
votes
2answers
811 views

Exporting a set of lat/long coordinates to SVG

Suppose I have a set of coordinates in latitude and longitude. What would be the easiest way to export those to an SVG file? I'd rather do this programatically (any language or library will do) ...
7
votes
1answer
849 views

Coordinate grid display on a rotated map

I have a series of maps that require me to rotate my data frame within my layout screen (north "rarely" points up in these maps). I ONLY want to show east coordinates on the top/bottom and ONLY north ...
6
votes
4answers
2k views

How to use Z-Coordinate in QGIS?

I was mapping an area in Namibia and also tracked a lot of paths on my way with my Garmin device... so I thought it would be nice to see height differences in my area (esp. interesting in the ...
6
votes
4answers
7k views

How to get coordinates from geometry in PostGIS?

This line: SELECT geom FROM myLayer.geom will return a hex value, i'm wondering how would it be possible to get decimal values, a result that look likes human-readable coordination? Regards,
6
votes
3answers
519 views

Classifying point coordinates to countries or continents?

I have about 50 000 points (latitude and longitude), and I would like to find out in which country each of the points is located. It does not need to be super precise, though. (Or actually I only ...
6
votes
2answers
358 views

What does coordinate system WG 21° mean?

I have a land survey document for a piece of land, it contains absolute coordinates that I would like to locate on google maps, but I don't know how to correctly interpret the data. What does the ...
6
votes
1answer
321 views

Coordinate system in aerial imagery

I am calculating WGS84 coordinates of points in an aerial image, given the WGS84 coordinates of the center of the image and the ground distance width and height (calculated from altitude and lens ...
6
votes
2answers
699 views

Shortcut to copy current cursor coordinates in ArcMap

Is there a shortcut or an extension to ArcMap 10 that would allow me to quickly copy (to clipboard) the coordinates at the current map position/click? I could implement such a functionality easily ...
6
votes
1answer
443 views

How to get latitude, longitude and altitude database from a GeoTIFF file?

I am developing an AR iOS application. When the iPhone gets the current location, it has to calculate locally the visible point. I want to read the tiff files in my application, and then get the ...
6
votes
2answers
2k views

Measuring distance between points in ArcMap - what coordinate system to use?

This is a basic -newbie - question. I have some handwritten data points taken off a GPS - so I am assuming they are in WGS 84, and I want to load them in ArcMap 9.3, via excel, and measure the ...
5
votes
3answers
620 views

Is there a tool to add “noise” to overlapping X, Y coordinates so they are no longer in the EXACT same place?

I have a series of points representing animal observations. Many of them overlap, having the exact same coordinates, and this is causing me trouble when I want to run some analytical tools which ...
5
votes
2answers
1k views

Coordinates(Latitude, Longitude) are different at same place on iPhone and Android devices, why?

I used HTML5 code for getting coordinates on Android (HTC desire s) with GPS enabled and iPhone (3gs). But the latitude and longitude are different on both devices at same place, why?. Difference ...
5
votes
5answers
2k views

Working out the coords of a square x miles from a center point

I am trying to create a x mile square (or circle) around a central point, where all sides of the square would be x miles from the centre. I need the 4 corner coordinates. It is scrambling my brain ...
5
votes
2answers
122 views

How to convert from one ellipsoid to another?

Introduction I have the following problem: I want to convert from WGS84 to "Anguilla 1957 / British West Indies Grid" (EPSG 2000). This seems to be straight-forward, as the transformation is a simple ...
5
votes
1answer
127 views

Sending coordinates via VHF Radios to Computers

I need to send and receive coordinates in NMEA format from a VHF radio to a computer. Any suggestions where to look in order to accomplish this task? The transmission will occur only when the user ...
5
votes
1answer
229 views

How do you fix Overlapping Lines?

I have a line dataset that contains some lines where the "end points" are actually found in the middle of the line. In the image below, the nodes are shown in green and one of the end points in red. ...
5
votes
1answer
340 views

How can I programmatically open an OnPoint map to specific coordinates?

We have an OnPoint server at work and I'm wondering how to open the mapping service and having it zoom in to my specified latitude and longitude. The reason I ask is because we have an application at ...
5
votes
1answer
351 views

Geocaching - XY coordinates

I was wondering what is the easiest way to get XY geocaching coordinates (by a particular Area of Interest (AOI)) data in a spread sheet format that I could covert to a GIS layer? On the ...
4
votes
2answers
4k views

Calculate bearing between two decimal GPS coordinates

I'm building a virtual tour application that uses custom panoramas in conjunction with Google's StreetView service. With StreetView, you can have 1 to n links at each particular location to move to, ...
4
votes
2answers
87 views

Why Different 2D Coordinate Transformation Methods Exist

It is a homework question but I couldn't find a satisfactory answer by googling. There are 4 different transformation approaches I'm asked for: - Conformal, - Affine, - 2D Projective, - 2D Polynomial ...
4
votes
1answer
227 views

Why does Calculate Geometry give incorrect number of decimals for Longitude?

intermediate ArcMap user here. I'm trying to calculate the geometry for a shapefile such that I can add lat/long columns to my attribute table. While I have no trouble calculating the latitude, the ...
4
votes
2answers
146 views

How to get XY coordinates and field values for each row in a SearchCursor?

I am trying to enumerate each row of a points shape file and get a certain field's value (elevation) and the xy coordinates. But I see I can only use: arcpy.SearchCursor to get the field; OR ...
4
votes
1answer
221 views

How to fix incorrect coordinate data for the mouse's position

I am running Quantum GIS 1.8.0 on a 64-bit Windows platform. I've imported a data set that plots correctly when overlaid with a Google Satellite map, so I know that the layer/project CRS is okay ...
4
votes
2answers
5k views

Convert X,Y State Plane coordinates to decimal degrees

I have 1000's of data point I need to convert from North Central Texas 4202 into Lat/Long decimal degrees. Can someone give me a conversion equation so I can quickly convert using excel? I have only ...
4
votes
2answers
1k views

How to update geometry in ArcObjects?

I'm just starting with ArcObjects and I want to update coordinates of geometry vertices. Specifically, I want to swap X, Y coordinates for each vertex of polygons (which can be multipart and have ...
4
votes
1answer
216 views

Spatial index vs two coordinates indexes

I have a table with two columns: latitude and longitude. I want to get all objects inside a "rectangular" (well, rectangular in a lat/lon coordinate metric) bounding box: min-max latitude and min-max ...
4
votes
1answer
1k views

Point interpolation in route

I have a set of GPS coords with X,Y and Course. I need to interpolate additional points based on the course of each point. It would be a simple line intersection based on lines drawn using the 2 ...
4
votes
1answer
112 views

Python libraries for correlating Photo to GPX file?

Can anyone recommend a Python library(s) that can geotag a photograph with the lat/long coordinates by correlating the timestamp of the photograph to the timestamp of a waypoint within a GPX file? I ...
4
votes
1answer
172 views

How to create cohesive Spatial Pixels from Spatial Points Dataset

I have a Spatial Point DF spo (covering an irregular shaped area of interest). The data are not on a regular grid due to crs transformation. My goal is a raster with predefined resolution and extent ...
3
votes
9answers
8k views

Creating shape file from file with coordinates

How can I make a shape file of an csv file with coordinates?
3
votes
5answers
4k views

Calculate midpoint from a series of latitude and longitude coordinates

I've got a series of longitude and latitude coordinates which represent a building outline e.g. -0.5485381346101759,53.2285150736142 -0.5482220594232723,53.22842450827133 ...
3
votes
3answers
8k views

How to get the coordinates in Lat/long from a point layer?

Sorry for asking this basic question, but I couldn't get the solution from the previous answers. I need to extract the Lat/long coordinates of the centroids of districts. My QGIS project SCR and the ...
3
votes
1answer
625 views

Interpolate undulations for given points using a geoid model

I have two databases, the first one (F.tsj) contains gps points: coordinates and ellipsoid heights and the second one is simply a geoid model where every line stores latitude, longitude, and ...
3
votes
2answers
204 views

Looking for Python module to do lat lon calculations

I'm looking for a Python module that can provide some / all of the following services using latitude/longitude to define points: Distance between two points Point in polygon Distance along a ...
3
votes
1answer
116 views

How to convert these mapping coordinates

I have an older database at work and I've been asked to map the recorded GPS coordinates for each record. Unfortunately, I can't figure out the map coordinates that were recorded. As an example, ...
3
votes
2answers
1k views

Update point coordinates in QGIS after manually moving locations in edit mode

I have imported point coordinates from a database, but I need to manually adjust a lot of the locations. Is there a way for QGIS to automatically update the point locations in the attribute table ...
3
votes
3answers
265 views

Formula for coordinates (lat, lon), azimuth and distance.

I would like to know how to find a set of coordinates on a small circle some distance from another point. For example, lets say A = (39.73, -104.98) #Denver B = (39.83, -106.06) #point ...
3
votes
1answer
99 views

How to center the map based on some (x,y) in QGIS?

I want to center and recenter the map loaded on QGIS using constantly changing (x,Y) Point. How should I do this using some code? My GPS device will write (x,y) to a text file. From there I get (x,y) ...
3
votes
1answer
59 views

How can I label both coordinates in mmQGIS?

How can I label both coordinates in mmQGIS? Everything I try leads to only one of the 2 coordinates (lat or lon) to be labeled. I cannot get both labeled at the same time.
3
votes
1answer
169 views

How to determine error radius of given points

I am running QGIS 1.8.0 on a 64-bit Windows 7 platform. Given multiple points with different (but close) coordinates, how do I automatically create a new point that programmatically takes into ...
3
votes
2answers
363 views

How to transform coordinates to location in x-y grid in R?

I have a polygon with a 40m diameter and several points that lay inside it. Now I want to reformat the point locations (projected in DHDN/GK-3, but could vary) to x-y coordinates ranging from zero to ...