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

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2
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1answer
67 views

Road Miles Calculation without Google Maps

We have two ZIP codes we want to calculate the road mile difference. Google maps states you cannot use their API if you do not show a map. Is there another service that provides this type of ...
4
votes
2answers
265 views

How to calculate the azimuth of a line of a multilinestring in PostGIS?

I have two spatially enabled tables in PostgreSQL with a geometry in each: First table is with POINT type, second is with MULTILINESTRING. I need to calculate the azimuth of the LINESTRING part of a ...
4
votes
1answer
179 views

How to find Closest Facility (euclidean distance)?

I have some facilities and incidents, and I want to find the closest facility for each incident. I've done it via Network Analyst (with a network dataset) but I'm wondering if you can do it with just ...
7
votes
4answers
506 views

How to calculate the “depth” of a linestring using postgis

I have linestring features, which look like bent linestrings, hemicycles or convex or concave linestrings. In the moment I can select the distance between the startpoint and endpoint of each feature. ...
8
votes
2answers
564 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 ...
4
votes
2answers
1k views

Spatial distance analysis in QGIS

I'm quite new to QGIS and trying to figure out how to analyze the following problem. I have three layers: settlements point layer with 253 entries waste treatment facilities point layer with 24 ...
0
votes
3answers
717 views

Return all results within a 30km radius of a specific lat/long point?

I have a table with a column the_geom which contains data similar to: ...
0
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2answers
416 views

How to determine average distance from points to line?

I have a polyline road dataset and a study area (polygon) covering the the road dataset. I want to determine the average distance for every given point within the study area to the nearest road. i ...
0
votes
1answer
56 views

QGIS proximity raster with extent beyond original coverage?

I need a raster coverage of distances from points outside the geographic region of interest, and am having trouble doing this with QGIS. Questions like this one (Calculating distance to points in ...
3
votes
3answers
708 views

How can I calculate the distances between my points in sequence automatically?

I have a rookie problem (again). I am trying to measure distances between points and writing the calculated measure between these points in the attribute table. The points represents a vehicle's ...
0
votes
1answer
47 views

Can distance be calculated to a destination feature based on an attribute in the source?

All, Is it possible to specify which destination point to calculate distance to based on an attribute in the source? STDistance will give me the distance each student (point) is to their closest ...
0
votes
1answer
70 views

Point to point distance over specified distance

I need to calculate the distance between neighbouring points which conform to a staggered line. I have two point datasets, one being the baseline and another the monitor. The points typically reside ...
3
votes
0answers
149 views

converting a distance to a map distance

I have a point and a polyline. I need to find the perpendicular distance between each segment of the polyline and the point. By each segemnt of the polyline I mean that, each polyline may contain more ...
1
vote
3answers
862 views

Generate random location within specified distance of a given point

In a simulation (not using any GIS), I need to generate a random location that is within a specified distance of a given location. I found a very helpful post here on this exact topic: How to ...
3
votes
1answer
853 views

Measuring distance between points along a river system

I have a forked river with multiple x,y data points along it and I need to measure the distance between these points when travelling along the river. However the forked part is throwing a wrench into ...
0
votes
1answer
660 views

SQL to get points within a certain distance

I am new to using spatial data types in sql server. I have managed to create a column of Approx 50,0000 geometry points (from x,y data) and would like to find out which (count number of) points are ...
2
votes
3answers
958 views

Calculate min distance between points in PostGIS

I have point layer in PostGIS database. Help please with query which add for each points in layer distance in attribute table between this point and another nearest point. Thanks! Update Calculate ...
1
vote
1answer
109 views

Distance between two latitudes [duplicate]

I need to know the distance in feet between the coordinates N34-00.000 and N34-00.001 (Degrees, minutes and thousanths of minutes) I computed approx 6 feet but am not confidant in my math skills.
1
vote
2answers
241 views

Why is pgrouting driving distance skipping edges?

I have a road network where I do a driving distance operation through pgrouting. This is my SQL: SELECT * FROM driving_distance('SELECT gid AS id,source,target, cost FROM ...
4
votes
1answer
346 views

Calculate distance to median point for a group of points in ArcGIS 10.1

I have a shapefile called "household_points" of ~2,000 points, which are divided into about 100 sites. The shapefile has a field in the attribute table called "SNAME" and in the field each point is ...
2
votes
0answers
58 views

Get distance after path distance allocation

I use ArcGIS 10.1 in Windows XP. I have a two point feature data sets One containing a single point P1 and another containing multiple points Pm. I computed the minimum-distance path from P1 to each ...
1
vote
2answers
355 views

Calculating millions of distances with Road Graph

I'm new to GIS but thanks to the answers I got in another question here on GIS stack exchange I was able to increase my knowledge significantly. This question is related to an earlier question I asked ...
1
vote
1answer
213 views

Mimimum distance between points (Postgres/PostGIS)

I have a table (tab_Cities with cities which own more than 50000 inhabitants. The table also contains lat, long and the_geom as columns. I can already see the points via QGIS. Now I want to write a ...
0
votes
1answer
78 views

Shortest path to nearest… something

I have a list of addresses and a map including train stations, schools etc., and I would like to calculate the shortest distance from each address to the nearest train station, school etc. I'm aware ...
3
votes
1answer
220 views

finding a location on a line using a point and a relative distance with arcgis js api

The problem I'm trying to solve is to find a point on a line given another point on the same line and a distance from the same point. I've been looking on the various RouteTask examples but they ...
3
votes
2answers
281 views

How to calculate distances between addresses and cities and coast line?

I am totally new to GIS, and so I apologize if my question is not clear enough. My basic problem is the following: I have about 160,000 Danish addresses with longitude and latitude for each address. ...
1
vote
1answer
542 views

Measuring Distance from Point to Point Along a Path in ArcMap

I am looking at a village and want to find the distance from each house (point) to the pagoda (point). However, I want the distance to be measured along a path (which I digitized as a polyline) and ...
5
votes
3answers
140 views

What is the precise distance from equator to pole according to WGS84?

For calculating areas of polygons by means of projecting to a cylindrical equal area projection I came across the following discrepancy: I ended up with a different distance, off by more than 5km, ...
0
votes
0answers
27 views

Bounding Boxes around nearby points [duplicate]

I've got a table with 200.000 points. My aim is to draw bounding boxes around points where this point have the same name and that are in a maximum distance of 500 meters to each other. I guess I can ...
1
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2answers
134 views

Distance between latlongs varies in different projection systems?

I have shapefiles with correct projections. The SRS is EPSG 32735 (WGS 1984 UTM 35S) Now, I have these two coordinates from this projection system: (31.3751,-23.4388) and (31.3779,-23.4355). ...
8
votes
3answers
592 views

Identification of consecutive points within a specified buffer

I have a point file, hourly relocations of an animal, and I want to be able to place a buffer around each point and calculate the number of subsequent points which are within the buffer zone. I am ...
6
votes
2answers
275 views

Projections appropriate for global analysis that preserve area and that preserve distance (but not necessarily in the same projection)

I am looking for a projection (or a set of projections) that decently preserve distances so that I can buffer every country in the world and have a similar level of minimal distortion for each. I ...
2
votes
2answers
266 views

Finding points along a path

I am unsure of the best approach to this problem. I can think of some ways of doing it which I will list below but I am looking for the best and most efficient way of doing this. Problem Given a ...
0
votes
1answer
171 views

How to correctly convert data from OSM with osm2po to use it with A* algorithm?

I want to make my A-Star fast, by using heuristics. At the moment it is very slow and even slower than my Dijkstra. I thougt A-Star is in the worst case as fast as Dijkstra. I convert my OSM bounding ...
4
votes
1answer
301 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
0
votes
0answers
85 views

Sort a collection of points based on proximity using pythagorean (2D) distance

I would like to present a user with a list of points, sorted by proximity to the user's location. Is there any problem with using the pythagorean formula to calculate the two dimensional distance ...
1
vote
0answers
118 views

How to create a buffer around a point that takes terrain elevation in account?

In QGIS, I am creating a few different buffer around points to simulate walking distances. For example, 10 minutes walk about 800m at 5km/h. Using population density, I then clip a population layer ...
1
vote
0answers
157 views

Calculate Distance Matrix for ALL possible combinations in the dataset in QGIS

I have a Vector Layer that is created out of a MySQL database and has the relevant points stored in WGS84 format. The import works well, however, when I try to calculate a distance matrix between all ...
5
votes
3answers
1k views

Dissolving polygons by attribute and in a certain distance (ArcGIS)

in a FeatureClass I have a lot of polygons which contain attributes of different landuse-types. Now I am trying to dissolve those polygons of the same landuse-type, but only if the distance between ...
2
votes
1answer
95 views

Calculating point proximity in ArcMap 10.1

I have a geocoded point file which (theoretically) contains one point for every zip code in the U.S. I want to create a smaller list of zip codes from this file. The list should include only those zip ...
3
votes
1answer
323 views

Find projection of a point to a line

I have a segment defined by 2 LatLon points(A and B) and a third LatLon point (C). I need an alghorithm, formulae, or some code to find the projection point of C on the segment AB (call this point D) ...
3
votes
0answers
268 views

How to calculate the distance to multiple locations from each cell of my raster?

I'm working with Arcgis 10.1 and Python 2.7.2 How can I calculate the distance to multiple locations from each cell of my raster? I tried euclidean distance but it only provides the distance to ...
1
vote
1answer
102 views

Converting NEAR results to Meters/Kilometers?

I am having trouble figuring out how to convert the units from the results of my NEAR calculations. I want to convert them to meters or kilometers, but cannot figure out how to do so... ...
2
votes
2answers
265 views

minimum distance from the shore (how to retrieve the “shore vertices”)

I am student of Statistics, this is my first time using GIS., I am sorry for the stupidity of the question but I browsed online and could not find a satisfactory answer. I have some spatial data in ...
4
votes
2answers
376 views

How do I find the average distance within a polygon to a point?

For my purposes, I can assume a homogeneous distribution of points within the polygon. What I want to find is the average distance from points within a polygon to a specified point. I don't know where ...
12
votes
6answers
4k views

What tools in Python are available for doing great circle distance + line creation?

I need to use Python to create a great circle distance -- both a number, and preferably some kind of 'curve' that I can use to draw in a client-side map. I don't care about the format of the curve -- ...
2
votes
1answer
67 views

How to compute the distance from the beginning of a line for every points using postgis

I have a line, for which I need to know, for every point that compose it, what is the distance from the beginning. The data is stored in PostGis 2.0 For example, for the line with the point a, b, c, ...
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0answers
105 views

Can QGIS Measure Line tool compute correct geodetic distance?

As I understood, this tool normally shows distance in the project CRS units, not the geodetic meters (despite it actually says the distance is in meters). However, now I read (Section III, 4 - ...
2
votes
0answers
197 views

Specifying a bounding rectangle using Google's S2 package for spherical geometry [duplicate]

This is my first post on GIS, I hope it is not too trivial a question. I work on a project on Google AppEngine, which is backed by a NoSQL datastore. This makes a proximity filter different from ...
2
votes
1answer
77 views

Where would a perfectly vertical vertical tunnel through the earth come out?

I am a programmer. I have a point P1 (lat,lon) given by GPS (WGS84) and I want to know the location of a point P2 if I make a straight line from P1 to the other side of the earth. I have read some ...