# Tagged Questions

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

86 views

### What is the real distance between positions?

I'm trying to figure out what gives me the most accurate distance between positions: Measuring distance directly (using Geod.inv)? Measuring distance in 2D (after transforming to a known projected ...
61 views

### GeoDjango and PostGIS distance query efficiency concerns [closed]

For example, if I want a query that says "show me all houses within 50km from here and order them from nearest to furthest", these are the questions and concerns I have: Assuming we are using EC2 (...
123 views

### Creating a point on edge of closest polygon

My project is looking at a grid in the ocean. I want to capture each ocean point's distance to the nearest coastline as a weight, and then use buffer to capture the sum of nightlight data within a 1 ...
635 views

### Distance between points along polyline ArcGIS for Desktop?

I'm using ArcGIS 10.3 (Desktop), and I'm trying to measure the distance between points following a path determined by a set of polylines. Hand measurement is not a viable option-- there are ~7500 ...
81 views

### Extend line to specific distance or a line

I want to extend my polyline to a given distance. How can I do this. I have attached image to clear my specification. I am using .net in ArcMap . I am also using python in the image, I want to ...
126 views

### Distance in meters between two geographic coordinates

I want to determine the distance in meters between two geographic coordinates. The points are: Lat (deg) Lon (deg) A: -33.3930906 -70.5452765 B: -33.3993212 -70.5468767 So if i calc the ...
37 views

### Points proximity to polygons in ArcGIS for Desktop?

I have a point feature class with 1725 records (spread out over NYC) and a polygon feature class with 13 records (also spread out over NYC). What tools or processes can I use to figure out what ...
89 views

### Buffer from Point or Polygon with Information from Raster

The intent of this work is to define a buffer around a point or polygon based on information from a raster. For instance if a polygon representing a city and the raster defines how long it takes to ...
46 views

### Select points greater than a certain distance from related points based on shared foreign key id

I have a PostGIS-enabled PostrgeSQL db, using QGIS, with data using EPSG:4326, and projected as EPSG:29903. I have a table with points with pk point_id and a table with images with fk point_id. I want ...
135 views

### How to calculate the distance to the nearest water source?

I have a polygon hydro layer of my study area and am trying to calculate the distance to nearest water bodies from my site. Since my site are 2km*2km grids I am not sure how to calculate it? Whether ...
270 views

### Calculate road distance between GPS points

I am working on tracking system that track location of vehicles on the map and tell their total distance from the beginning till today. I have device_id, timestamp and GPS location in the table like ...
73 views

### Get the 2 points immediately before and after a given point in PostGIS

In the picture below: The given point is C, I would like to select A and B, but not Z (which is closer to C than B but it's not immediately after in the LineString). Note that C is always ON the line ...
95 views

### ST_Distance loop

I want to create a postgresql function which calculates the distances between random points who are stored in one table. For the Table: CREATE TABLE s_1( id bigserial primary key, the_geom geometry, ...
171 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 st_distance").order("...
48 views

### using a linear solver to get a “centre of gravity” of a set of points

As a programmer, if I have a linear solver available. How can I formulate the following problem as a set of constrains / decisions / goals for the linear solver? I have a matrix of say 10*10, so 100 ...
97 views

### How to calculate multiple distances between set of points and vector grid in PostGIS?

My set contains the following input data: A set of points and a hexagonal (vector) grid. For each cell in the grid, I want to calculate the driving-distance to each point. I thought this would be a ...
65 views

### Create a line from an array and measure its length with PostGIS (ST_MakeLine, ST_Length)

do I understand it correctly that it is possible to create a line out of an array with the function ST_MakeLine()? I would like to create a line from several points (more than two) and then calculate ...
55 views

### PostGIS point distance from polygon not 0 when on edge

I have a pretty simple problem: SELECT * FROM ST_Distance(ST_GeographyFromText('POLYGON((70 -40,70 -39,71 -39,71 -40,70 -40))'), ST_GeographyFromText('POINT(70.48 -39)'), False) returns 118....
928 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: ...
66 views

### Divide line by length with QGIS [duplicate]

I'm a newbie using QGIS 2.12 and I'm trying to split a line in QGIS and place points every x meters. There is a tool in ArcGIS (divide by length add in). How to achieve this in QGIS?
93 views

### How to measure nearest neighbor in miles or kilometers between two point layers using QGIS?

I have tried to look for an answer to this question, but cannot find an adequate solution. I have two point layers. One is of locations by lat/longs of homes in Louisiana. The other is a layer of ...
27 views

### Measuring large distances when all layers are in decimal degrees using QGIS?

I just developed a distance matrix between various points across Canada in QGIS. The distances produced are in decimal degrees, and I would like to view them in metric. I am unsure how to do this.
163 views

### Find nearest road distance between two points for over 1000 points

I'm extremely new to QGIS and am learning the material on my own. I have two CSV files with latitudes and longitudes, one has school address information and the other has fast food restaurant ...
788 views

### Measuring Right of Way in ArcGIS Desktop?

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 ...
70 views

### How to calculate shortest path from points in one layer to points in another layer via roads, in QGIS

I'm a new user of QGIS (and have experience using ArcGIS but zero programming skills) and I'm looking for a way to calculate the shortest path from addresses to subway stations via a network of roads. ...
40 views

### How can I measure the distance between many polygon features and either another polygon or a line in QGIS?

I often have to manually measure the distance between a single site and other sites around it, but obviously this can get long-winded and I feel like there must be a much more efficient way of doing ...
26k 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 ...
33 views

### Extracting distances along a line from postcode a centroid to the nearest point (bus stop)

I'm looking to measure the distance from postcode centroids (point file) in a city to the nearest bus stop (point file) along the road network (line file). In Qgis I can calculate the distance but ...
3k views

### Calculating distance of points along route using ArcGIS Desktop? [closed]

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 ...
272 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 = ...
128 views

### Projection for Calculating Distances in Continental United States?

TL;DR Question: I want to calculate distance from point to edge of nearest polygon for 2,000 points in Continental United States. What is the best projection to use? Full Question: I have two ...
123 views

### Obtaining road distances between each pair of points in point feature class using ArcGIS for Desktop?

In Calculating attribute for network distance between multiple points in ArcGIS Desktop?, an explanation has already been given how to find road distances from a certain point to each point in another ...
72 views

### Copying point features along line features by predetermined distance

first post here. I searched the forum for this issue but other cases were slightly different. Anywho... I have points in a feature class. Each point has its centroid on a unique line feature in a ...
3k views

### Best formula for calculating short distances in UTM?

I'm fairly new at calculating distances with precision, but I wanted to know what is the best formula for calculating short distances in UTM coordinates. The distances that I'am calculating are all ...
41 views

### Find points within X distance with a specific variable

I am trying to use QGIS to find points within 5 meters of each other that all have a value of <50% for a given parameter that has been loaded through a CSV file. I looked in to doing it with a ...
63 views

### Calculating distance to a fixed point on a map

I have a point with latitude 40.7127837 and longitude -74.00594130000002 I have imagined this point on a plane like this Latitudes run from West to East and longitudes run from North to South Can ...
193 views

### How to use ST_DWithin to query features from one table within a distance of a specific feature or features in another table

I'm pretty new with PostGIS. I have a parcel layer and a census block layer in a postgres database, and I would like to be able to query out all census blocks within a specified distance of a specific ...
67 views

### How to find records using a distance filter, in a table of Points?

My table fields are: POSIC (id, geom, dt_inclusion). DB is PostGIS. Data comes from a GPS Source, then i can create a route ordening the points by Date_Inclusion. So, lets say i have registries A,B,C ...
173 views

### Calculate The Minimum Distance from Polygon Centroid to Edge

I am looking to calculate the minimum distance from the Center of a polygon (A crescent shaped polygon would have a center inside the polygon) to its edge. I have parcel data and I am trying to ...
17 views

### OLS regression Analysis

I want to use distance to major roads for census block groups as an independent variable for my model. So I was told to do a Spatial join with census blocks groups to get a distance field, however ...
439 views

### Distance between a Point and Linestring: PostGIS/GEOS vs. Boost

I am currently using the GEOS library through OGR and data from a PostGIS database to work with geospatial data. I now found myself in the need to use some of the algorithms Boost.Geometry and Boost....
1k views

### Calculating distance from points to different class in raster using ArcGIS Spatial Analyst?

I am looking for some advice on how to calculate the distance from a point to a different class of a raster. Specifically, I have observations (points) of animal use overlaid on land cover data. ...
373 views

### Create circles around a point on a map measuring the radius in hours

Disclaimer: I am not experienced in GIS and hope this question fits in this category. I was wondering whether it is somehow possible to create a circle* around a city, using Google Maps or the like, ...
203 views

### Find point close to points from postgis table

I have a postgis point table with a large list of cities. I need to find duplicates in it, but only if they are 10km close each other, which means that is the same city. For example, I have 5 points ...
69 views

### Calculate the latitude,longitude 1000 kilometers east from a given location [closed]

I am trying to calculate what would the Google maps latitude and longitude be, for a given location, 1000 east from it. I am not looking for an application which can do, this, but rather a manual way, ...
88 views

### Distance Measure using QGIS Field Calculator?

A QGIS newbie who can't for the life of them work out the expression needed to represent distance from a point. I want to show how a walkable a neighbourhood is. I need do to this by showing what ...
532 views

### Calculating distance between two points on map using ITM coordinates?

How to calculate the distance between two point on the map using ITM coords? i have a map with items on it all with ITM coords and i need to return all items in X meters of radius from my location. ...
54 views

### Distance Analysis from single point to multiple points on vector layers

Is it possible to do the following in QGIS: Create a text file that plots the distance from a single point (stored in one layer) and multiple points (stored in another layer). I have tried to use ...