# Questions tagged [distance]

The measure of separation between two entities or locations that may or may not be connected, such as two points.

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### What's a term for Sea Level Distance which is usable by novice users?

I've been using the term Sea Level Distance to describe the total length of a line string where I ignore the elevation and just calculate the distance from point to point along the ellipsoid and sum ...
15k views

### How do I get the distance meter value between two geometries in PostGIS?

I have a simple question about calculating distances in PostGIS. I would like to get the distance between two geometries. I am using this sid : 4269 in meters what i am doing now is this : ...
2k views

### Appropriate distance metric for spatial clustering of geographic coordinates

I have a set of locations in geographic coordinates, and I would like to group the points using hierarchical clustering followed by tree-cutting at various "heights" in order to calculate group-wise ...
347 views

### Projecting gps data to get length of resulting line shape in ArcMap 10.0

I have gps data in WGS84 geographic coordinates. I will use the gps data to build a line shape in ArcMap 10.0. The data falls in UTM 15N. To get most accurate length of line, should I project the ...
11k views

### Distance between GPS coordinates

Given a database of GPS points, a center GPS location, and a radius R (in meters), how can I find all points in the database that are within a distance of R of the center point? Will the distance iso-...
1k views

### QGIS layers no longer overlay when Enable 'on the fly' CRS transformation is on

My QGIS project has two layers - one retrieved from GADM (administrative boundaries of Guinea Bissau) and another one of the villages collected in the field using GPS Decimal Degrees - D.ddddd. If I ...
2k views

### Finding the minimum and maximum distance between an observer and a lat/lon bounding box

I have three points in geographic coordinates (latitude, longitude, altitude). One of the points represents an observer, above the Earth. The other two points define a bounding box. I'd like a ...
9k views

### Calculating distance to points in QGIS

Is there a way of calculating the distance to the nearest points in QGIS? In ArcGIS there is a function called Euclidean Distance, which can take an input vector or raster, and generate a raster of ...
2k views

### How to use/interpret/visualise a distance matrix with unknown coordinates?

How would you go about using a distance matrix where points have no coordinates, i.e. what useful statistics can be made and how to visualise it in some useful way?
17k views

### Simple PostGIS ST_Distance query for two points from the same geometry table?

Note: This question was published at Stackoverflow at first. I have a geometry table points_table with SRID 4326 and a few points in it. I need to find a distance between a pair of points (features) ...
2k views

### How to use Google's Distance matrix on server side?

I am developing a web application wherein i need to find the closest bus-stop from a users location and mark it on a map. I have the list of bus-stops on my server. I am using Google's Distance Matrix ...
2k views

### clip linestring by length

Is there a way to clip a linestring based on distance? For example, linestring from a to b is 150 meters. I would like to get the linestring from a to a point that is is 75 meters away from a ...
199 views

### Calculate Point C using distance and bearing from points A and B? [duplicate]

Possible Duplicate: Calculating Lat/Lng X miles from point I'm from old school so have not done math for ages. So I need some help to solve this problem, please :) I have two points such as A(...
1k views

### Calculating radius / buffer on EPSG 3785 in meters vs buffer in WGS 84 in meters

The goal is working in EPSG 3785 and in particular Google Maps, one wishes to render (on a tile) a circle of a given radius in meters. The rendering is done in pixels. I would guess that one could ...
5k views

### Using a list of geographic locations, and determining the X closest locations to a user-defined location

I've got a list of geographical locations in an Excel spreadsheet. I want users to be able to search for a user-defined location, and then have the X number of closest locations from the list pulled ...
2k views

### Transform polygon to equivalent circle, QGis

I have a polygon and I'd like to find the radius of an equivalent circle from a particular point within the polygon. The polygon would have a large (infinite) number of points evenly distributed ...
1k views

### Plugin for average distance from node to polyline in QGIS?

Is there a plugin available that will calculate this? EDIT 1: The red polyline is the average distance of the point to the black polyline. The red polyline is what I want to display. Alternatively, ...
4k 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 ...
40k views

### Looking for a Tool to Calculate Distance Between Points (Between Layers)

I am a college student using ArcEditor 10.0 for a semester project measuring distance to hospitals from census tract centroids. This is my first time using ArcGIS, and I have no formal training. So ...
8k views

### java vividsolutions jts wgs-84 distance to meters

my (java) project uses com.vividsolutions.jts.geom, which provides a distance function. After some googling I finally found that the return value from this function is in central angle degrees, when ...
3k views

### Using a geodjango PointField with geography=True, my distance calculations are wrong

Here's my model: class ExchangeArea(models.Model): """ An Exchange Service Area, calculated from a phone exchange and surrounding census tracts. """ coordinates = models.PointField(...
624 views

### PostGIS ST_Distance vs. pgRouting

I am looking to create a city directory web app, and the site will need to be able to calculate distances between two geospatial points (like the distance between the user and a restaurant, or the ...
1k views

### Distance between points and polygons in QGIS / PostGIS

I need to work out the distance between a table of polygons and a table of points. The table of polygons has different site boundaries, and the point table has points relating to each of the site ...
2k views

### MySQL Query to fetch all cities and POI's near the route

I'm implementing alghorithm to search POI near the route (array of Lat, Long points). My problem is that I don't know how to calculate distance beetween line segment and POI. Look at picture that I ...
1k views

### How do I query for all polygons within a distance from a point?

Call me stupid, but somehow I couldn't figure out how to do the following. I've got a testing shapefile with 18 features, which I successfully imported into GeoDjango (1.3, running on Spatialite). As ...
9k views

### Distance between lat/long points

I am attempting to calculate the distance between two latitude/longitude points. I have a piece of code that mostly works that I yanked from this post but I do not really understand how it works. ...
5k views

### Calculate distances between series of points in postgis

I have a postgres/postgis table containing a series of sequential points. I want to add a new column to the table which contains the distance between each point and the first one, and so forth until ...
2k views

### Looking for a Java library for tracking positions, and querying regions

I have a deceptively simple requirement to create a software component to record and update some mobile position information, then be able to perform simple queries concerning mobiles in a particular ...
410 views

### Total newbie. Creating map from aerial photo of golf course in QGIS

I have a aerial photo in tif with a tfw file of the golf course that I work at. I would like to create vector data of different features on the course such as greens fairways tees, etc. to calculate ...
340 views

### How to check if parcel is located by golf course

Is there any simple way for me to run millions of parcels through some type of script to see if a shape file parcel is on a golf course? For example if I have a layer that has all the golf courses and ...
1k views

### Calculate coordinate ( lat / long ) with another coordinate and distance

I already have a formula that can calculate the distance between 2 geographic coordinates: public function getGeoDistance(Coordinate \$geoCoord1,Coordinate \$geoCoord2){ if(is_object(\$geoCoord1) &...
400 views

### Metric/parameters to compare length of polyline

What would be a good metric to compare the length of two polylines? A very naive approach would be to define a maximum delta which the two lines can differ. I'm looking for more approaches. For ...
576 views

### No difference between distances measured in projected and non-projected data

I'm performing measurements of distances in Km between a lot of localities by using the "Point Distance" in ArcGis 9.3. I realized that the results obtained after using projected coordinate system are ...
1k views

### Getting a square mile bounding box anchored by coordinates?

Let's say I have a lat/lng coordinate pair. I want to determine the coordinates that would create a square mile box. The existing coordintae pair would be the top left of the box, and the coordinate ...
15k views

### Algorithm to find nearest point

I've a list of a few hundred cities with their latitude/longitude. Given another location (also in lat/long) I need to find the nearest city. As I don't use any GIS, by now the obvious algorithm is ...
2k views

### Surface distance on DEM between two coordinates

Given two coordinates on a digital elevation model (DEM), how do I compute the actual distance traveled between the two locations, assuming a straight line route? How will changing the resolution of ...