# Tagged Questions

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

148 views

### Postgis ST_Distance query returning inaccurate results

I am using the following query to retrieve records from a postgresql DB @services = Service.select("*, ST_Distance(services.lon_lat, ST_GeomFromText('POINT (lat lon)', 4326)) as ...
194 views

### How to calculate the average point spacing for a layer of points in QGIS?

I have a set of points and want to calculate the average point spacing for further analysis. ArcMap has the 3D Analyst Point File Information for this but I'm searching for an alternative in QGIS. ...
467 views

### QGIS Azimuth and Distance plugin length issue

Relative newbie to QGIS and trying to figure out exactly what I'm doing wrong. A couple days ago I had azimuth and distance working perfectly. I was using it in a different project with different ...
117 views

### Merging rasters which overlap using ArcGIS for Desktop?

I need to merge two rasters which overlap, both indicate distance values. I need the output of the merge to result in the shorter/lower distance value. I am using ArcGIS 10.1. I hope it is more ...
4k views

### Calculate longitude length in miles

Suppose I have geographic coordinates of "Saratoga, California, USA" as Latitude: 37°15.8298′ N Longitude: 122° 1.3806′ W I know from here that in case of latitude 1° ≈ 69 miles and that ...
114 views

### Calculating Distances Between Geometry Columns of Differing SRIDs

I am attempting a relatively simple task but have been running into trouble. I have two tables, one which has lat and lon points which were geocoded using google (SRID 3857) and another table which ...
193 views

### Proof of part of haversine formula?

I'm trying to study how to find the distance between two points if their latitudes and longitudes are given. I have a question about the proof of part of the haversine formula given at Math Forum. ...
753 views

### Need to get distance matrix for large set of points on-the-fly

I do not know much about GIS and I do not know much of the jargon. Hopefully you can help me a bit here because I am really unaware of the services and software available. My problem is as follows: ...
71 views

### How to calculate the shortest path to pass on 7.000 UTM points?

Anyone can give me an advice how to calculate the shortest path with a lot of UTM points? In total I have 7000 points, but it can be grouping 100 or 500. I have knowledges about Java and Python for ...
114 views

### Euclidean distance outside a Polygon (ArcMap)

I got some university coursework to analyse the best potential areas for a residential development project and I'm currently doing multi-criteria evaluation. One of the shapefiles in the dataset given ...
628 views

### Calculate distance between a set of points: lat and long in QGIS or R

I have shapefiles containing the location of several individuals along several months. Positions were documented with a 30 minutes interval. Tables contain the following data fields: collar (ID), ...
118 views

### Euclidean Distance between two lines

I have two lines in ArcMap 10.2.2 and was wondering if it is possible to create a raster showing the Euclidean Distance between them. Like to map each cell on one line to its nearest cell on the other ...
52 views

### Given distance (in meters) what is the angle in geographic reference systems? [duplicate]

In QGIS and other systems sometimes I have a layer in geographic reference system (typically WGS84, EPSG:4326) and I'd like to calculate a buffer of say 5000m around a point. So, given a point ...
194 views

### 'Find your nearest' type function with a large dataset

In a previous employment, I needed to display a "Distance to stockist" on our website. It would get your current co-ordinates (from a postcode or HTML5 geolocate) and then display a list of nearby ...
67 views

### Distance to, travel only on one surface

Looking to create a distance to wetland raster. However this travel distance must be through the water only. I have tried setting land to a high cost (e.g. 99) however doing so I have to set each ...
118 views

### How do I interpret this proj4string and why doesn't changing units change its resuls?

I'm new to GIS - I have a background in statistics. I have the following proj4string: '+proj=lcc +lat_1=40.66666666666666 +lat_2=41.03333333333333 +lat_0=40.16666666666666 +lon_0=-74 +x_0=300000 ...
69 views

### Which projection should be chosen to model transmission lines across the USA?

I am looking at different options for high voltage power lines in the US. These power lines cross several states. Since in the end the distance is of importance, is the USA Contiguous Equidistant ...
93 views

### QGIS distance from point to line along a specific bearing

I've got a vector layer with points (representing customer locations) and another vector layer with a line (representing the coast line). I want to calculate a "smart" distance to coast. Specifically, ...
128 views

### Postgis: Query ST_DWithin in square instead of circle

The ST_DWithin query queries all geometries within a certain radius from another geometry (in my case a point). For performance optimization of my application I want to query in a square. So that the ...
248 views

### Cost Distance interpretation in ArcGIS 10.2

I am using the Cost Distance tool in ArcMap 10.2 to find the how far it is to walk to the closest area of green space along the road network in a town. I have a input raster of the location of the ...
613 views

### Convert java.vividsolutions.jts.geom distance to meters

I am using com.vividsolutions.jts.geom to perform the distance calculations. I have a list of "LineString"s and a Point (Say A). I want to determine the The nearest LineString to the Point A. The ...
82 views

### Calculating position in SRTM grid

I'm actually trying to calculate a grid point position in a SRTM grid by row and column count. So I got a position by lat/lon, then calculating the row and column in my hgt-file (this post helped me) ...
4k views

### PostGIS nearest point with ST_Distance

I need to obtain on each element on one table the closest point of another table. The first table contains traffic signs and the second one the Entrance Halls of the town. The thing is that I can't ...
45 views

### Assign points with varying radii to central meeting locations

I have a set of points in a city, each with a maximum distance radius of 0.5 - 1.5 miles. From this set of points, I'd like to create a small number of 'meeting points', i.e. locations that are ...
92 views

### ESRI Javascript API pan parameters

Using the ESRI javasript API, is there a way to set the distance the map will move when panning? When I fire the map.panUp(), for example, it pans, but about twice as far as I would like it to.
48 views

### Distance between coordinates

I placed some cones on a sports playing field and estimated their locations using latitude/longitude coordinates. An example pair of estimated latitude/longitude coordinates is 54.96975, -1.51407. On ...
29 views

### Creating a distance overlay that is computed by the distance of points/lines and recalculated on zooming

I created a fictional map and visualized it with d3. Now I would like to show a scale/rule so that the user can see which distance (kilometers,meters) he is currently using. I was thinking about ...
195 views

### Calculating distances in Geographic Coordinate System using ArcGIS for Desktop?

I work in a Geographic Coordinate System and using the "Generate Near Table" tool in ArcGIS 10.2 for Desktop. I want to calculate the distances that each feature of the point layer has to the closest ...
680 views

### Geographic Heatmaps with Concentric Circles by Distance

I'm looking to generate a geographic heatmap (using 'ggmap') that overlays some dimension (to start, housing prices) over the lat/lon near a city center. Then I want to create circles of equi-distant ...
56 views

### Calculating distance between many users of a handful of facilities, a small hangup

I am trying to calculate distance between thousands of people and a handful of facilities. I know the ArcGIS ROUTENAME issue has been addressed many times in forums. I have scoured them and am hung ...
91 views

### Calculating distance between previous and current addresses for large file

Hoping to get help with this. I'm a fairly new QGIS user and trying to solve the following problem: Let's say I have a large dataset (5000+ records) of customer addresses, previous and current, and I ...
98 views

### distance between paired points in separate shapefiles (paired by attribute data)

I have a point layer with site_code attribute data. I have another layer of points in different locations but with the same site_code data. How can I find the linear distance between points that are ...
733 views

### GeoTools - Find distance in meters between point and path in lat/lon

I need to find distance in meters between some point with given latitude and longitude and line (on Earth) defined by several points with lat/lon coordinates. I read this questions: first second ...
15 views

### How to set a polyline length as per a given Image

I have an image of a map representing the road networks. I have converted these road networks into a shapefile with only polylines. I want to set a distance to this road network. For e.g I know from ...
158 views

### Computing distance from points to coastline

I have a shapefile with the nodes of a grid I have applied, for the purposes of interpolation, and I want to compute the euclidean distance that each grid node (it is a point vector) has to the ...
46 views

### QGis measure tool does not continue to measure within point symbol

We are using QGIS more and more, however, today a colleague noticed something strange when using the measure line tool. We have point features and different symbols of different sizes and colors are ...
496 views

### Finding and selecting locations in database near 10 km distance from path

In the Google Maps API, I have this Javascript. It is finding and showing user the shorter path between two cities. <!--////// \\\\\\\--> <style> #panel { position: ...
614 views

### Trilateration using 3 x,y points and 3 distances, all in cm [closed]

I want to find out the position (x,y) of a given point, knowing the distance from 3 x,y points. Below you can view the x,y coordinates and their given distances in cm. B1x = 795 B1y = 332 B1d = ...
44 views

### Get latlong at a distance on a path

I have 2 decimal point in lat/lon. I want to divide the line drawn by lat/lon into parts each at a specified distance, lets say 'x' -- all except the last segment will be of length x -- and I need the ...
156 views

### am I setting up data from google geocoding correctly for ST_DWithin search?

Sorry to ask a basic question, but I have not been able to find this laid out entirely anywhere. I am mostly relying on this SO post: What Spatial Reference System do I store Google Map's Lat/Lng ...
667 views

### postgis calculate distance between point & polygon/circle

By basic requirement is to find the nearby fences to a particular point(user lat long alt) within a N meters. I have list of polygon/circle in DB with 900913 srid ...
125 views

### Using the accCost() function in R: questions regarding the transition layer

I am trying to use the accCost() function from the gdistance package in R. I load my cost raster using the raster()function from the raster package. According to the documentation, I need first to ...
378 views

### How to convert distance in meters(EPSG:28406) to EPSG:900913 with OpenLayers?

For point I use OpenLayers and transform(): numZona = Math.ceil(parseFloat(lon)/6)); Proj4js.defs["EPSG:28406"] = '+proj=tmerc +lat_0=0 +lon_0='(parseInt(numZona)*6-3)+' +k=1.000000 ...
368 views

### Calculate Euclidean distance to raster WITHIN multiple polygons

I am using ArcGIS 10.1 on a Windows x64 system. I am working in a study area where I have 360 000 locations of about 50 territorial animals. I have a shapefile containing 125 sometimes overlapping ...
79 views

### A bit of help using Google maps

I have 1000 or so points on a map, (I have GPS coordinates. I would like to use google maps to find the shortest distance using roads, between pairs of points. I would like to measure all pairs within ...
343 views

### Trilateration Calculation Issue

edit I was able to do this following partially from this solution: How to calculate the intersection of 2 Circles? I broke it up into 3 groups of intersections AB, AC and BC. Once I had those I took ...
674 views

### geotools Linestring distance in meters

I want to use geotools for working with gis data. I'm most concerned about distance calculations, not so much about drawing a map. What I still couldn't figure out is how to make distance calculations ...
248 views

I try to calculate distance between two cities and I'm in big confusion because the results are wrong. I have a model in geodjango like this: class Address(geo_models.Model): coordinates = ...
228 views

### Calculate the distances between n geographical points

First of all, I'm sorry if my question is stupid, but I'm totally new to the world of GISs and geographic measurements. I would like to calculate the distances between N (an arbitrary number, but ...
263 views

### Identifying south facing mountain land, above an elevation, within a slope range, less than fixed distance from major roadways

This odd question comes from believing that such an analysis is plausible in a GIS system. Only, I don't how to accomplish the various discrete steps implied from the Title, nor where to get a topo ...