The measure of separation between two entities or locations that may or may not be connected, such as two points.
0
votes
0answers
50 views
Interpretation of MODIS VCF Data, concerning walking distance analysis
I'm still working on my diploma thesis (must be one of the last ones in germany..;)) which deals with distance analysis. I want to model walking distances and cost paths affected by slope, vegetation, ...
2
votes
1answer
226 views
How to find the closest Edge from a Line
Currently I'm working on a basic 3D model viewer in MATLAB, which can import .OBJ files (modeled in e.g. Blender). The purpose of this viewer is to test different subdivision schemes (like ...
1
vote
1answer
800 views
How to get the shortest distances between features on separate polygon layers?
Suppose I have a county-level map for the state of North Carolina, U.S. Suppose I would like to compute the shortest distance of each county to any point along the border of Georgia. How would this ...
1
vote
2answers
292 views
GeoDjango Order by distance for Model that is linked to User who has a location on their user profile
I need to order my query model by distance, however the point field in question is not on the model class but on the user profile and the i am getting an error when attempting the following.
g = ...
3
votes
1answer
102 views
Method to compute and visualize the closest set of facilities from OSM data
I want to use OSM to extract a set of facilities e.g. school, park, hospital inside a given region.
from that, transform the area in grid and for each cell in a grid compute its score mixing the ...
0
votes
1answer
100 views
If the Earth was flat, what unit of measurement would distances between geographic points be represented as?
A whole lot of abstraction- given two longitude/latitude points given from a GPS, I'm using the Pythagorean distance formula to find the distance between them. What unit of length would the distance ...
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 ...
7
votes
5answers
887 views
Calculate distance in km to nearest points (given in lat/long) using ArcGIS
I have two point datasets in ArcGIS, both of which are given in WGS84 lat/lon co-ordinates and the points are spread across the whole world. I would like to find the nearest point in Dataset A to each ...
2
votes
2answers
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 ...
3
votes
1answer
201 views
How to make a minimal distance matrix for polygons using QGIS?
I have a set of polygons and I want to find minimal distances between the edge of each pair of them. It's similar task as in this question:
How to find the minimum edge to edge distance of polygons?
...
1
vote
1answer
212 views
PgRouting Driving Distance crashing postgis server
I haven't used PgRouting much so I'm a little in the dark here. However, I am attempting a driving distance calculation like the one described by Underdark here.
My SQL is identical, I have a ...
1
vote
0answers
84 views
Is there a ModestMaps or other flex library for finding the distance between 2 lat/lon coordinates?
I'm using ModestMaps in my Adobe Flex application. Is there a flex library method to calculate the distance between two of my lat/lon coordinates, or am I stuck coding the Haversine by hand? I've ...
4
votes
2answers
2k views
How to calculate new point coordinates from distance and angle?
I want to calculate the coordinates of a new point.
What I have: The source point coordinates, the distance (meters) and the angle
For example: I want to create a point within 100 meters and 45 ...
2
votes
1answer
77 views
How to Improve a Distance Model
I am working on a distance model that creates distance rings around a given point and assigns those rings a probability. The point is in the center of a 25 x 25 km area, and the model fails to assign ...
10
votes
3answers
3k views
How to cluster spatial data in R?
I am very new to R, so please bear with me : >
I have bunch of data points with latitude and longitude. I want to use R to cluster them based on their distance.
I have already taken a look at this ...
8
votes
2answers
702 views
Calculate Distance between a Polygon and a Point Along a Path
I am very new to ArcGis and am trying to figure out how to do this.
Basically, this is what I am trying to do:
I have a map of Canada and in it I have polygons representing areas (each about the ...
1
vote
0answers
23 views
Translate geographical coordinate [duplicate]
Possible Duplicate:
Calculating Lat/Lng X miles from point
I would like to know how could I translate a geographical coordinate to an specific distance. So for example let's suppose I'm ...
7
votes
3answers
4k views
How do I calculate the bounding box for given a distance and latitude/longitude
Hi need to be able to calculate a bounding box or circle for a Given WGS84 latitude and WGS84 longitude, and distance but have no Idea where to start! The distance from the start lat Lon would be 10KM ...
0
votes
0answers
279 views
Implementing custom (Vincenty/Haversine formula) functions for MySQL vs Using PostGIS?
I currently am using MySQL for all of my relational data. I have hit a crossroads with geo calculations. Since, MySQL does not have good support for spatial functions, I am contemplating on using ...
4
votes
1answer
1k views
Distance calculation : Integrating incremental gps data
I am trying to build a GPS based odometer based on android.
Currently , I am calculating incremental distance changes very frequently ( < 5 meter movement). The distance calculation in android is ...
3
votes
0answers
79 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 ...
2
votes
1answer
433 views
MySQL GeoSpatial function for ST_Distance_Spheroid? Metric used in return Type of GLength?
Is there a ST_Distance_Sphere, ST_Distance_Spheroid equivalent function in MySQL's GeoSpatial Support?
If not, any way to emulate this?
What is the metric used in return type of ...
3
votes
3answers
1k views
How do I determine the center point of several features in OpenLayers?
I have several polygons being drawn on a map, usually representing a country or province or state. Depending on some chosen data, different regions may be selected, so what I was hoping is that ...
19
votes
2answers
344 views
Precision when working with spatial data in GIS
Is there a basic or introductory study that examines and compares the precision of spatial data when working
with varying precison of the data input, like having 1, 2, ... decimal places?
with the ...
6
votes
2answers
258 views
how to find the point in a country furthest from a boundary
i'm trying to find the point in south africa furthest from the sea or a landward boundary.
my method thus far:
i obtained a first guess at the centre of the inscribed circle and the three segments ...
7
votes
1answer
558 views
PostGIS - Calculate progressive distance between points on a GPX path
I am attempting to build an elevation profile using PostGIS-PostgreSQL only.
I have imported GPX data in my PostGis database, so now I have a table full of the GPS coordinates of the track and the ...
4
votes
1answer
231 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 ...
5
votes
1answer
119 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 ...
3
votes
1answer
148 views
How to calculate maximum distance to an interpolated value along a contour in QGIS?
I'm planning to enter concentrations of groundwater contaminants collected from well locations into QGIS and then use interpolation functions to create contours of the groundwater plume. Can QGIS ...
1
vote
0answers
117 views
How to create a dynamic distance calculator for selected line feature classes?
My situation:
I am relatively new to GIS so forgive me if this is a stupid question. I am working on a project at a park that I am interning at where the goal is to create a single feature with ...
3
votes
2answers
1k views
How to find a point on given line that its distance from another point is given also?
I have this input:
(lat1,lon1), (lat2,lon2) - Two coordinates that create the line
(lat0, lat0) - Point on this line
d - distance
I want to find a point (lat, lon), where
(lat, lon) is on the ...
1
vote
1answer
911 views
Measuring on OpenLayers map
These days, I am trying to develop web map using openlayers. I copy source code from here
Then I changed code to display my data.B ut it does not work, even map is also not showing. In chrome shows ...
1
vote
2answers
779 views
How to get vector feature information (distance and extent ) on OpenLayers
I have basic WMS layer and vector layer in openlayers. Using EditingToolbar i can draw some features as shown below
Then I want to get some information (like distance and extent) of drawn features ...
1
vote
1answer
233 views
PostGIS - table with 3d points with fast ordering by distance
I am pretty new to PostGIS and I am trying to solve the following problem.
I need a table with 3D points (x,y,z) that will contain around 1-10million points. I want to be able to efficiently ask the ...
2
votes
0answers
451 views
Calculate cumulative distance between points in a dataset in ArcGIS 9.3 ArcInfo
I am working with several point datasets that I have received, with the points representing xy locations with elevation data for several levees in south Louisiana. I would like to be able to calculate ...
5
votes
1answer
265 views
How to compute the distance between centroids and polygons?
Suppose I have an Excel spreadsheet with the latitude and longitude of the centroid of every county in the U.S. I want to know the shortest distance from each county to any part of Oklahoma ...
2
votes
1answer
2k views
How to find nearest point for each point in current layer?
I have a point layer and want to know the distance of nearest point of current layer for each point in the layer.
I found some tools in ArcToolbox about it , but they need two layers for input and ...
4
votes
1answer
819 views
Distances in {Plate Carrée projection - EPSG:4326 - WGS84}
So,
"4326 is just the EPSG identifier of WGS84" [3], indeed http://spatialreference.org/ref/epsg/4326/html/ says it is a GEOGraphic Coordinate System:
GEOGCS["WGS 84",
DATUM["WGS_1984",
...
1
vote
1answer
869 views
distanceTo is giving wrong result in OpenLayers?
Hi i am using distanceTo from OpenLayers to calculate the distance between two locations
these are map details
Geographic = new OpenLayers.Projection("EPSG:4326");
Mercator = new ...
2
votes
4answers
1k views
Geodjango- get the distance between 2 points
Sorry to be asking yet another geodjango newbie question.
What I want to do is quite simple, I have 2 locations defined by gps coords, lat / long like returned by google maps:
...
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 ...
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 ...
5
votes
1answer
358 views
How to find the two furthest points between a group of points?
I have a table with 20000 records and with those columns Shop, longitude, latitude, geom
I would like to find a way to find the pair of ths farthest shops between a selection of shops
For example we ...
4
votes
1answer
347 views
Calculation of average point distances from one another within a polygon grid
I am working with processed LiDAR data of forested areas in ArcMap 10, with various area based statistics extracted for each 30x30m polygon grid-cell in a shapefile. There are approximately 20,000 of ...
3
votes
2answers
583 views
How to calculate how long an arc second is for a given long/lat?
The title says it all, really. I am wondering what area is covered by a dataset which is one arc second wide.
Thanks,
Rob
7
votes
3answers
197 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 ...
3
votes
2answers
577 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 : ...
7
votes
1answer
424 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 ...
4
votes
1answer
242 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 ...
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 ...
