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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1answer
111 views

What do different realizations of the same datum have in common?

Firstly, am I correct in assuming that the process of determining the shape and the size of the spheroid is independent from the process of determining the origin and the orientation? For example, ...
2
votes
1answer
206 views

How to smoothly join two rectangles

I am looking for the Math and steps involved not using a tool. We have PostGIS but its an old version so we are working with the data in Python. Given three coordinates: -107.37, 52.46 -103.24, ...
2
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1answer
478 views

How can I show points on the same coordinate as e.g. a bigger symbol in QGIS?

I use QGIS 1.8 for mapping archaeological findings. Some of the findings within one layer are located on the same site and therefore have the same coordinates. Therefore you just see one point instead ...
2
votes
4answers
634 views

Get coordinates from address

I am writing a application which allow users to save a address into database (db) and in the next step it shows all addresses on a map. But in the saving step I need automatically calculate a GPS ...
2
votes
1answer
967 views

Getting polygon shapefile node coordinates and point order

I am trying to get the coordinates of each node of a polygon in QGIS. What I basically did is use the following tools: Vector -> Geometry tools -> Extract nodes Vector -> Geometry tools -> Export ...
2
votes
1answer
1k views

Understanding the difference between coordinates projection in OSM and Google Maps

I'm looking at the coordinate differences between Google Maps and OSM. I'm a noob in the technicality behind GIS. Having read: EPSG 3857 or 4326 for GoogleMaps, OpenStreetMap and Leaflet How to ...
2
votes
1answer
3k views

Trying to set the OpenLayers MouseOver position to be outside the Map

This is my code and I am trying to obtain the MouseOver to be displayed outside the Map container. <!DOCTYPE html> <html> <head> <title>My Map</title> ...
2
votes
1answer
1k views

How to find bounding coordinates (lat/long) for UTM zones?

I want to error check incoming lat/lng points by checking if the point resides within the given UTM zone. (This would work for the data im using because sometimes there is a missing sign or lat/lng is ...
2
votes
1answer
622 views

Read .DEM (USGS) FIles with C#

I have a huge number of .DEMs and have been investigating how to process them into something useful. Does anyone know how, or even if it is possible to read coordinates and elevation data from ...
2
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0answers
22 views

Calculating lat/long coordinates from DLS (Dominion Land Survey) Location

I am trying to calculate the legal subdivision center of a DLS location and even when I try the simplest calculation my numbers are always off from other calculators. Take for example DLS location ...
2
votes
1answer
24 views

Populate X and Y fields in SDE Point Data Using SQL trigger

Here is my situation. I am running ESRI ArcGIS Server and Desktop 10.2 on SQL Server 2008 R2. I would like to populate the Latitude and Longitude fields from point data (Signs data collected using ...
2
votes
1answer
31 views

From LiDAR .txt to QGIS map

I have Lidar data in .txt files (1000 to 26000 KB), where 2nd column marks x-coordinates, 3rd col y and 4th col z. 8 485000.16 6508997.48 1.84 66 Last 2 485001.27 6508998.92 1.86 82 Last 2 485001.02 ...
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0answers
121 views

Inserting coordinates from Google Maps into a Database

My question is pretty basic. I am using Android Google Maps to take the coordinates off a location on the map and I want to insert it into a PostgreSQL database. I know I have to use PostGIS but how ...
2
votes
1answer
52 views

How to use qgis coordinate transformation in user code

I am now working with coordinate transformations between different CRSs, e.g. latlong to UTM. After comparisons, I found out that the coordinate capture plugin in QGIS is quite accurate for the ...
2
votes
1answer
41 views

warping and outputting coordinates of GeoTiff data: advice and error checking

So I have a massive TIF file (projected in Lambert azimuthal equal-area), and I'm trying to get lat/lon coordinates for each point of the grid. My first step is to warp the projection to the WGS84 ...
2
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0answers
99 views

Calculating Distances between coordinates

I have perused through the other questions that are very similar to mine but am still having some trouble. I have 75 coordinates in WGS84 that I brought in from an Excel table. They are now on my ...
2
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0answers
65 views

Getting XY screen coords from ArcScene 3D point using ArcObjects?

I already know how to convert screen point (X,Y in pixels) to 3D point: ISceneGraph pSceneGraph = m_pSceneHookHelper.SceneGraph; IPoint pPoint; pSceneGraph.Locate(pSceneGraph.ActiveViewer, X, Y, ...
2
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0answers
54 views

Choosing the map scale (1:nnn) for the given raster dimension

Starting points: let define the raster image size, say: 1800x900 pixels I want draw my own raster image map - by drawing polygons e.g. like "draw line from pixel with coordinates x100y100 to pixel ...
2
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0answers
42 views

Problem with finding point within the box in MongoDB

I'm doing a search within box. It works perfect except only one situation. Let me describe it. Suppose the point has coordinates: (lng:-155, lat:19) If we have box: sw - (-170, 10), ne (29,69) that ...
2
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0answers
39 views

Decimal degree coordinates: how many decimal places to use for …? [duplicate]

When using coordinates in decimal degrees, how many decimal points actually make sense? For example, say one is producing a table of locations of base camps in a report, there's no point in ...
2
votes
0answers
40 views

Is it safe to store coordinates on NFC tags always in one CRS and rely on conversion for others

I'm involved in NFC (Near Field Communication) standardization of a record structure for geographic point locations. That will allow to put coordinates on NFC memory tags which can be read with a ...
2
votes
1answer
229 views

Determine when I have crossed state line?

We are currently using the Google Maps API to get route information and total mileage but we would like to determine when we are crossing into a new state. When we return the route information we can ...
2
votes
2answers
265 views

How to add XY coordinates (latitude/longitude) to a DEM raster in ArcGIS 10.1

I would like to add xy coordinates of about 10 sites to a raster. I am using ArcGIS 10.1 and my xy coordinates are on Access 2013 database - saved as .mdb. The steps I have taken so far: 1) In ...
2
votes
0answers
117 views

How to locate a house on the 3D Map correctly?

I've done my 3D map generation in WebGL/THREE.JS project and have an issue with the building locations. I have the data about building position ( its polygon ) from DB server, but first of all I want ...
2
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0answers
132 views

Height of the geoid in ECEF coordinates

I know that the relationship of geoid height N and ellipsoid height h to orthometric height H is defined by H = h - N, but what if I have some position in Earth-Centered-Earth-Fixed (ECEF) ...
2
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0answers
247 views

PyProj/Proj4 convert geographic to projected coordinates for Geostationary Data

I am trying to convert geographic coordinates (in degrees east/north lon lat) to projected coordinates in meters for geostationary full disc data (GVAR Goes East data from CLASS). To do this, I tried ...
2
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0answers
458 views

How to limit a specific area in order to have a topographic 3D map using MatLab?

I am using MatLab, I want to build a topographic 3D map, I am following this guide, I have been doing the steps listed on the section Draping Geoid Heights over Topography, and I do not have any ...
2
votes
0answers
287 views

Plotting X, Y coordinates generated from MySQL database in QGIS

Currently running QGIS 1.8.0 on Mac OS X 10.8.4. I can plot points on a map using the "Add delimited text layer" plugin to get x-y coordinates from a text file. However, I'd like to be able to ...
2
votes
0answers
146 views

Should 2D Positions and 3D Positions be considered conceptually different entities?

Let's suppose we want to model GeographicPositions, described by coordinates or coordinate tuples inside some Coordinate Reference System. Also, these would be put inside some sequence to represent ...
2
votes
0answers
164 views

Comparing two spatial datasets statistically

I'm new to this forum. I'm working on the following problem - I have two datasets. Let's call it dataset A and B. Both of them will contain a set of points like A1,LonA1,LatA1 A2,LonA2,LatA2 .. .. ...
2
votes
0answers
136 views

Interpolate current Course value of GPS using previous Course values

I have a set of GPS data with Lat, lon and Course. I need to interpolate current value of course, using previous values of Course. The formula I am using is not accurate in curves.In C language I was ...
2
votes
0answers
449 views

Mean coordinates in QGIS

I am using QGIS v 1.7.4 for MAC and I am trying to calculate mean coordinates for a set of points using ftools. To calculate my result I am going to Vector -> Analysis tools -> mean ...
2
votes
1answer
928 views

Plotting latitude on to a (Mercator projection) SVG representing a country map

I want to convert (google sourced) longitude and latitude coordinates to x and y to place points on a SVG map I can get the longitude converted to X but I can't nail latitude. ...
1
vote
2answers
191 views

Coordinates values change for ArcGIS

I have received thousands of location information like below. X= 10°52.579 Y= 078°38.473 I don't have idea in which format is this, please let me know what is the format of this location and ...
1
vote
2answers
590 views

How to remove z & m coordinates from shapes with QGIS? (Or arcgis, grass, gdal, Python…)

I've recently received some parcel data in shapefile format that has z & m coordinates (all = 0.0). The WKT for a typical parcel looks like this: "MULTIPOLYGON (((2672464.560700002 ...
1
vote
1answer
512 views

EPSG:4326, EPSG:3857, JOSM and unprojections

It is said here that EPSG:4326 is not a projection. In my mind, a projection is a transformation of the surface of the Earth producing a flat image, notably a bitmap. We know that WGS84 (World ...
1
vote
2answers
651 views

How do you convert to degrees and minutes from 8/9-digit lat/lon DMS code? [duplicate]

I'm trying to map the national bridge inventory, but the coordinates are stored in this 9-digit code for longitude (and 8-digits for latitude) EXAMPLE: Longitude is 81°5.8' Code is 081054800 Page 9 ...
1
vote
1answer
843 views

How to compute mean coordinates?

Can anybody explain how to compute mean coordinates? Regards.
1
vote
1answer
93 views

Coordinate system doesn't contain values in the range -180 to 180 and -90 to 90

I'm creating an android version of a PC program (I've contacted the company who owns the PC program, so it's legal). The program is in the core a GPS, but is used to navigate pre-defined routes for ...
1
vote
3answers
80 views

convert csv to kml or geojson, etc using ogr2ogr (use “latitude” and “longitude” attributes for coordinates)

I've just unsuccessfully tried to use ogr2ogr to convert CSV into KML like so: ogr2ogr -f "KML" output.kml input.csv The csv has "latitude" and "longitude" columns. The attributes are all loaded ...
1
vote
1answer
58 views

Uses for “Calculate Geometry” option

Is there another use for "Calculate Geometry" aside from calculating area, length and points? I already read the help section ArcGIS Help (10.2, 10.2.1, and 10.2.2) and it's very informative. ...
1
vote
1answer
123 views

How to write a expression in field calculator for finding $X and $Y?

I'm trying to calculate the lat/long of points using the Q GIS field calculator.Nathan W suggested to First, save the layer as WGS84 and import it again. Then in the field calculator you can use $x or ...
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vote
1answer
335 views

generate random world point geometries

I have a world map. I need random point geometry. So, how can I randomly generate point coordinates? Any programming language. Also, I am using SRID 4326. Any programming language.
1
vote
1answer
153 views

Converting mercator meters without UTM zone?

I've been attempting to extract track information from Humminbird (Side Imaging Sonar) binary files and have hit a stumbling block with the coordinates it provides. The values are apparently in ...
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vote
2answers
34 views

Identifying my coordinates from external datasource

I'm working with data received from an agency outside of my office and two columns in the dataset are labeled 'CompX' and 'CompY'. Here is a sample set pulled from the spreadsheet: ...
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vote
1answer
2k views

How to get LatLng array from geoJSON Layer in Leaflet?

i need to hand the latlng coordinates from my phpPostGIS-served geoJSONLayer as an array over to a new added HeatMap Layer. L.geoJSON has an build-in option: coordsToLatLng( coords )" and a static ...
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vote
2answers
701 views

Changing layer extent to decimal degrees?

Using ArcMap or ArcGIS 10 ... In the photo below, you can see my extent is in meters while my projected coordinate system is in decimal degrees. How can I convert my layer extent to decimal degrees? ...
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1answer
231 views

How to find nearby objects using Easting and Northing range

I have a bunch of objects which have associated Eastings and Northings in format OSGB36 for example: 265397 869562 547297 179002 If I have a starting Easting and Northing, and wanted to find ...
1
vote
2answers
74 views

qgis polygon to coordinates

I have the ordnance survey postcode polygons, i can get the centre point on the postcode (Using polygon centroids) and all the corner coordinates (using extract nodes) Does anyone know how to export ...
1
vote
1answer
79 views

Draw an item from coordinates in QGIS?

Is it possible to draw a line or to draw a triangle or another figure by digit the coordinates of the vertex? I use QGIS 1.8 on windows 7 system.