The measure of separation between two entities or locations that may or may not be connected, such as two points.
2
votes
0answers
426 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 ...
4
votes
2answers
5k 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 ...
0
votes
1answer
105 views
ArcGIS WebADF Distance tool
Is there a tool in the WebADF that will let me draw a straight line and calculate the distance between the two points.
2
votes
2answers
662 views
ST_Distance versus ST_Distance_Spheroid?
As my client software uses lat/lon coordinates when communicating with my (spherical mercator) postgis database i decided to ST_Transform every geometry to WGS-84.
However i noticed that ST_Distance ...
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 ...
5
votes
2answers
366 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 ...
4
votes
2answers
2k 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 ...
3
votes
1answer
684 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 ...
2
votes
2answers
618 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 ...
1
vote
1answer
696 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 = ...
9
votes
3answers
630 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 ...
2
votes
1answer
355 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 ...
5
votes
2answers
398 views
Calculate stop times/distances of transport lines - tools and procedure?
I need to calculate stop times of bus lines (extrapolation)
I have:
Shape file with all stops
shape file with control points where bus time was taken
Shape file with all bus routes
csv file with ...
4
votes
1answer
556 views
How to generate a point distance matrix using shortest network distance?
My problem is as follows.
To start with, I have the following spatial datasets:
A road network;
13,000 odd point locations representing populated localities (ie places where people live);
Service ...
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 ...
2
votes
1answer
691 views
Find distance from a point to linestring
I have table (shapetable) with my coastline shape file loaded. I have another table (pointtable) with lat long points. Wondering how would i go about writing a sql query to find the distance between ...
4
votes
2answers
245 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 ...
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 ...
4
votes
2answers
1k views
How can I compare two point shapefiles that contain lat/longs and compute distance?
Greetings everyone, I have 2 sets of point shapefiles in ArcGIS (group A and B), each set has around 1000 entries that contain lat/long. What I want to do is compare Group A against Group B and figure ...
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 ...
7
votes
3answers
276 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 ...
4
votes
3answers
2k views
How to properly utilize DWITHIN Spatial Filter in OpenLayers
Given the following code:
var points = [];
points.push(new OpenLayers.Geometry.Point(-110, 38));
points.push(new OpenLayers.Geometry.Point(-108, 40));
var lineString = ...
4
votes
1answer
537 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) ...
3
votes
3answers
365 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 ...
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, ...
4
votes
1answer
663 views
Does the Bing Maps API have a distance to coast service?
Does the Bing API contain a distance to coast service from an address? All we need to do is calculate the distance to a major coastline (Atlantic or Gulf of Mexico).
2
votes
2answers
249 views
normalizing Haversine distance
I need to normalize the Haversine distance.
What's the maximum Haversine distance ? The Earth circumference I guess ? how much is it ?
thanks
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 ...
2
votes
1answer
907 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 ...
7
votes
2answers
2k 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 ...
4
votes
2answers
2k views
Calculate distance of points along a route
I am struggling with the calculation of the distance between points along a stream (points are located 0-20m away from the stream) in ArcGIS 10. The points are simple xy-data in UTM.
I created a ...
6
votes
2answers
235 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 ...
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 ...
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
656 views
How do you produce a output table containing distances between mineral grains at various azimuthal directions?
I am using ArcGIS 10, the newest version and I am a senior at Western Carolina University and working on my senior thesis and the data set in which I have are images of mineral thin sections all ...
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 ...
8
votes
3answers
611 views
What kinds of line segments/edges require high accuracy in a true surface-of-the-ellipsoid representation?
I've been musing (and doing prototype coding) for a 'projection free' geographic codebase with your basic point, line & polygon primitives.
Rather than dealing with all the sacrifices that come ...
8
votes
3answers
728 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 ...
6
votes
1answer
489 views
Is it impossible to measure Right of Way in ArcGIS?
I'm helping bring CAD people into ArcGIS so that everyone throughout the company is on the same page and there is one database for everything. Right now, one of the biggest hurdles is making sure all ...
4
votes
1answer
349 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 ...
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
...
11
votes
3answers
3k 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 ...
2
votes
3answers
916 views
Distance between a line layer and several other line features (arcGIS 9.3 Arcview Licence)
I have a "Drain" line layer (with 150 lines) that I need to calculate the distance from lines to all objects within 120m. I've tried doing a spatial join and its great but I need more than just the ...
10
votes
2answers
809 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
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.
...
3
votes
2answers
232 views
Test case for geo-distance implementation?
I wrote a method, based on this presentation, that filters points based on their proximity to a target point. I would like to write a few test case. What would be good test cases for this method?
// ...
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 ...
4
votes
5answers
7k 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 ...
7
votes
5answers
2k views
Which tools and methods can be used to create isochrones?
I'd like to get an idea for what's involved in creating isochrones for a series of sites, with a reasonable degree of accuracy to the estimates. A general outline would be great, though my scenario ...
5
votes
4answers
818 views
Looking for a fast, open-source raster cost-distance function to use in code
I've been scouring the internet for a fast, open-source cost-distance function that I can embed inside my code. The functionality should basically work like the ArcGIS implementation where I can ...
