The measure of separation between two entities or locations that may or may not be connected, such as two points.
34
votes
5answers
3k views
Why is the 'straight line' path across continent so curved?
This is the result of mapping the straight line path from a point in US to Poland using Distance Measurement Tool.
Also, planes from Asia to US would travel almost over North Pole.
Why is the path ...
15
votes
3answers
5k views
Why is law of cosines more preferable than haversine when calculating distance between two latitude-longitude points?
In fact, when Sinnott published the
haversine formula, computational
precision was limited. Nowadays,
JavaScript (and most modern computers
& languages) use IEEE 754 64-bit
...
7
votes
4answers
4k views
Calculating Lat/Lng X miles from point
I am wanting to find a latitude and longitude point given a bearing, a distance, and a starting latitude and longitude.
This appears to be the opposite of this question (Distance between lat/long ...
14
votes
1answer
499 views
How accurate is approximating the Earth as sphere?
What level of error do I encounter when approximating the earth as a sphere? Specifically, when dealing with the location of points and, for example, the great circle distances between them.
Are ...
14
votes
3answers
2k views
How do I find the distance between two coordinates in an ellipsoid?
Lets say I have two sets of latitude and longitude. How do I find the distance between the two locations if I assume the earth is a perfect ellipsoid (with an eccentricity of 0.0167)?
8
votes
3answers
734 views
What is the right solution (and map projection) to compute distances between points located all over the World?
After my study on map projection I realized that it is very difficult to choose a projection that allows to compute simultaneously the distances between a great deal of points if these points are ...
7
votes
2answers
1k 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.
...
15
votes
5answers
5k views
Trilateration using 3 latitude and longitude points, and 3 distances
I want to find out an unknown target location (latitude and longitude co-ordinates). There are 3 known points (latitude and longitude co-ordinate pairs) and for each point a distance in kilometers to ...
10
votes
5answers
2k 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 -- ...
4
votes
1answer
1k 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 ...
5
votes
5answers
454 views
How to calculate distances in a point sequence?
I'm looking for help calculating the distance between a sequence of points that are in a single Shapefile in QGIS. Below is what my data look like and a blank distance column I've added to show how ...
3
votes
1answer
944 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 ...
3
votes
2answers
2k views
How to use Distance Matrix tool in QGIS?
I have a point data set. Now there are cluster of points based on a field. So I take out one such cluster which has points with same field.I want to find distance between all the points in cluster and ...
12
votes
3answers
193 views
How can I represent distance using the dashes or markers of a vector line?
I am a very basic user and dont know the lingo to get to the gist of my question so some background might help.
Ive volunteered to create a pre-incident planning system for my rural fire department. ...
8
votes
4answers
2k views
How to find the minimum edge to edge distance of polygons?
I have a a map of about 3000 polygons in ArcGIS 10. I'm looking to find the distance between each one of them. I know how to do it using the lat and long coordinates of the centroid, but I'm looking ...
7
votes
4answers
1k views
Connecting line features and determining the length of the longest line
I have a line feature (see image) representing a river that I created using the Stream_to_Feature tool. The attribute table contains several records representing different lines - the problem is the ...
9
votes
3answers
635 views
How can I find the most remote spot in Eastern United States?
I have this hunch that I could travel no more than 50 miles from the most remote spot in the Eastern United States (east of the Mississippi River), in the direction of the nearest road, and find a ...
6
votes
5answers
2k views
Better Distance Measurements in Web Mercator Projection
I am working with an ESRI stack, storing my layers in a sql-spatial-enabled-SDE- geodatabase (Geometry type, Web Mercator-3857).
I am building a web mapping application, so by default, the tiles are ...
4
votes
3answers
2k views
Splitting lines automatically at specific distances?
I have a set of polylines I need to split at varying distances from their starting points. In general I'm looking for a something similar to the SPLIT function within the editor tool. There it is ...
4
votes
3answers
341 views
How to efficiently find points within an elliptical area?
Using PostGIS 2.0.0 I need to filter the results of a function, which returns many POINTs, to find the ones that lie within an elliptical area defined by two points and a distance (all parameters ...
4
votes
5answers
8k views
For every point, distance to nearest polygon of type X?
In ArcGIS how might one calculate as an attribute value the distance to the nearest polygon of type X? Say we have a point layer of wildlife observations and we want to know how far each of them is ...
3
votes
1answer
1k views
QGIS calculate distance of point along a line
I have a polyline (movement path) and points recorded along the line. I would like to calculate for each point the distance along the line in Quantum GIS. I hope for a result which will add a new ...
2
votes
3answers
1k views
How to perform trilateration using 3 lat/lon points without distances?
I read this thread Trilateration using 3 latitude and longitude points, and 3 distances explaining about trilateration using 3 latitude and longitude with measured distance.
The problem is I want to ...
1
vote
2answers
299 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 ...
7
votes
4answers
8k views
How to find the distance of a point along a polyline?
We need to find the distance of a series of point along a given polyline.
We have a polyline dataset repsenting rivers in a catchment, broken up into river reaches (FID 1 through 35 for example).
We ...
3
votes
3answers
3k 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 ...
10
votes
2answers
810 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 ...
7
votes
3answers
194 views
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 ...
5
votes
1answer
461 views
Get shortest distance between two geometries in ArcPy
I'm using ArcPy and using a cursor to step through one polygon feature class. For each of these 'source' polygons, I am creating a SearchCursor to find all polygons in a second feature class that ...
4
votes
1answer
221 views
Correct use of the terms geographic, path, and Euclidean distance
I often use the terms geographic and Euclidean distance interchangeably when referring to the length of the shortest straight-line distance between two points on a map. Is this correct?
I use the ...
3
votes
1answer
829 views
How do I perform a proximity search with Postgis?
OK, so I downloaded the Geonames database (cities1000) and wrote a small Ruby program to import them into my table (geo_cities). I then added geography column called geog.
So after all of that, I ...
0
votes
0answers
150 views
Is there a tool that tells how many features there are within a set distance in ArcView?
I'm looking to create a raster, in ArcView, that represents how many features (either points or polygons) are within a certain distance from any given location within a study area. I know there must ...
7
votes
2answers
2k 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 ...
4
votes
2answers
615 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, ...
2
votes
1answer
56 views
Create raster distance around a single point feature class
Okay, so I'm relatively new to ArcMap and I'm trying to use the Fuzzy membership for suitability test. I have a single point feature class that I wanna use for this analysis. I know that in order to ...
2
votes
1answer
915 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 ...
2
votes
1answer
2k views
How to calculate distance between two locations using stored procedure in MySQL?
I have a database with locations with its lat and long coordinates. The area of locations is quite small with lots of them quite near each other.
Im using this stored procedure in my project. ...
0
votes
0answers
45 views
how to create Euclidean Distance in QGIS
I'm trying to create distance layer for points in QGIS (similar to Euclidean Distance in ArcGIS).
I see the answer you give in the url
Calculating distance to points in QGIS
I try it using rasterize. ...
0
votes
0answers
17 views
Can I apply the Euclidean Distance tool for a single point feature class? [duplicate]
So, as suggested in my previous question, I tried to perform perform the Euclidean Distance tool for a single point feature class. For som e reason it doesn't work and the error given is ERROR010092: ...
