Questions tagged [measurements]
Measurement is finding a number that shows the size or amount of something.
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Planar vs geodesic
My understanding is that geodesic is measured on the surface of the ellipsoid and is the always the shortest distance on the earth. Planar is just straight line distance. Is this the correct ...
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Change default unit for measure tool
Every time I open the measure tool in QGIS 3.28 I change the units to feet but it defaults back to meters. I tried settings -> options -> map tools & updated preferred distance units to feet,...
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Distance between point layers in QGIS
I have data points where respondents have indicated where they were on vacation (variable pointsSH). In the attribute table of these data points is stored where the people live (the zip code). I also ...
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Calculating the straight distance of non-straight polyline in QGIS
I have a GIS layer of bus stops (MultiLineString), which contain the paint lines that are painted on the asphalt.
The complete bus stop element is in a single MultiLine element. If I select it:
I ...
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Calculating temperature from multi-spectral map in QGIS
I have a map showing heat islands in a large city in the form of a multispectral (RGB) raster. I'd like to obtain the temperature or at least a temperature scale (the ultimate idea is to be able to ...
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Creating Multiple Instances of Measure Line
I'm trying to use multiple instances of the Measure Line and Area at the same time. More specifically, I need to measure setbacks from lot lines. The way Measure Line is set up, it becomes quite a ...
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Mergin Maps measure function available
Project works find. I use Mergin Maps on Windows 11.
But I need an essential function: Measure area and lines
Is there no function for that?
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QChainage only creates points using None/Planimetric measurement
I am using the QChainage plugin to make points every 1 nautical mile on a line set to CRS of EPSG 4326. My project measurements were set to Ellipsoid - WGS 84 (EPSG: 7030) in order to match Google ...
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Generating lines at the end of each measurement with plugin in QGIS
It would be very useful to have a tool like this when measuring and even more useful to generate lines at the end of the operation.
I use this plugin which is part of a small GIS program (Map Maker 3....
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How could I fix QGIS measuring incorrectly my distances?
I made a QGIS project to calculate some measures about the city I live in (in Belgium).
Problem is, I noticed that I get very different results when measuring elements, in Google Maps vs in QGIS.
...
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Is the Geo URI uncertainty a radius or a diameter?
Uncertainty is inherent in geospatial data... Maybe it's supposed to be obvious, and, some standards forget to define it.
The RFC 5870 — A Uniform Resource Identifier for Geographic Locations ('geo' ...
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In ArcPy I need code to transform M-value to coordinate X,Y
Input: route linear feature
M-Value as input from text box
Output: X,Y value
I need code to convert a measure value to X,Y coordinate. The measure value is an input value.
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Measuring real distance in QGIS
I created the linear shapefile of an ancient Roman Road (via Flaminia), and I would like to compare the linear total distance with the real one: Roman engineers and Gromatici measured the roads with a ...
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Calculate edge length of a feature in layer WMS
How to calculate edge length of a feature and display the result on the corresponding edges in layer when clicking on that feature.
Looks like this:
This is my WMS layer:
var myLayer = new ol.layer....
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Calculation of the distance between intersecting lines, but according to existing lines
I will try to briefly describe, namely, it is a forest area and polygons mark some kind of reference area, roads are lines, and there are also tractor roads (the same lines) which in this case are the ...
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Inconsistent Line lengths and distance measurements
I've imported OSM data, including specifically LineString railroad tracks for different subdivisions.
I want to distribute mile markers at fixed intervals, but am getting very different distance ...
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How to compute theoretical GPS accuracy?
I'm a student and I am working on a GPS-like system.
I have implemented a few algorithms (Newton-Raphson, Bancroft, ...) and I would like to compare them.
Basically, I have a constellation of ...
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How get distance in degrees to calculate buffers in AWS Athena?
Athena only allows to calculate the distance of the buffer in decimal degrees but this value varies with respect to the latitude in the globe, tate to obtain a distance according to the following ...
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QGIS measure tool: How to edit default SR on ellipsoidal method?
When I use the measure tool on QGIS 3.22, about ellipsoidic method it says: "Coordinates has been transphormed in the choosen ellipsoid (EPSG: 7030)": this sounds strange because all CRS ...
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Measuring tool crashes on QGIS 3.22.5
When I open the measuring tool to measure distances QGIS crashes. I am using the LTR Version 3.22.5. I have two small a layers in the projected to EPSG:28355 and base layers sourced from rest ...
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Сreating buffer in meters using GeoPandas
I want to use a built-in function buffer of GeoPandas. I want to create a buffer of 10 centimeters around the original geometry but buffer method take argument in degree, so what value do I need to ...
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Grouping and measuring total length of road based on specific attribute in QGIS
I have this dataset that describes the cycleways of a city.
I want to measure the km of cycleway for each type of highway (residential, track, unclassified, ecc) and then calculate the percentage of ...
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Getting distance of lines between points on map using Distance matrix in QGIS
I created a Distance matrix from a vector layer of 36 points. I want to show all the distance lines between all the points.
In the Distance matrix layer, I click Properties > Symbology, then under ...
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Creating square polygons of given length from single corner point in QGIS
I have 30 points, each one represents the SE corner of a 1.5 by 1.5m plot. I want to create polygons to represent these plots.
How do I create square polygons from a corner point and with a specific ...
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Calculating Commute Between Residential Address and Childcare address
I have an Excel sheet (10,000 + rows) that has the residential address and the provider address.
I am trying to see the distance a parent travels to drop their child off to their specific provider. I ...
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Calculating distances between a set of coordinates
I'm using QGIS 3.2, WGS 84, EPSG 4326. I have a series of coordinates that represent the location of Red Squirrel trail cams in a Forest, there is another file with every sighting date and location ...
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Finding mean distance between cluster center and points in cluster in QGIS
I have done the following in QGIS: I used the integrated k-means clustering tool to cluster around 160k data points into 50 clusters. Using the mean coordinate tool (Vector analysis > Mean ...
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Will two GNSS modules displace by the same amount?
I am using two gps modules with blunos (bluetooth arduinos) too get the distance between them and display it on a phone. This has worked great and on avg Im getting the expected 5m inaccuracy.
However ...
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Calculating length of each polygon side in PostGIS
In PostGIS, I want to calculate the length of different sides of a polygon. I know how to calculate a perimeter but how to calculate length side by side?
Perimeter is as a sum of side's length so I ...
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Calculating polygon area in QGIS without adding new field
Is it possible in QGIS to quickly calculate the area of a polygon using a Processing tool, plugin, script without adding attributes or creating a new layer?
Something launching the results window or ...
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Why ellipsoidal distance measured in EPSG:7030 in QGIS?
I measure distance (km) in QGIS (Ctrl+Shift+M)
.
In Ellipsoidal, it using CSR EPSG:7030.
In Cartesian, they didn't say what projection is used.
If it using ellipsoidal option, does it mean measured ...
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Can the Getis-Ord Statistic really be considered a measure of spatial autocorrelation?
The Getis-Ord statisic
G_i(*)= \Sigma_j w_{ij} x_j / \Sigma_j x_j
basically calculates a geographically weighted average at some point. Is it fair to say that it is rather a measure of spatial ...
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Geodetically correct point spacing accounting for change in elevation
I am trying to create a grid of points at a specific spacing (30ft) for setting up a new orchard on fairly steep terrain. I have tried using "create fishnet" in ArcGIS pro. This is giving ...
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Calculating distance between two points using QGIS C++ APIs
I have been trying to find the distance between two points using QGIS C++ APIs in Qt. I used the following code :
QgsDistanceArea d;
d.setEllipsoid("WGS84");
qDebug()<< "...
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Why accurate area of all countries cannot be obtained using a single EPSG code, even if it corresponds to an equal-area projection?
I would like to check if using different equal-area projections lead to near-identical area estimation for a list of countries.
Importing modules:
import numpy as np
import geopandas as gpd
import ...
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Required DLL for calculating distance between 2 points
I have been trying to find the distance between 2 points using QGIS C++ APIs in Qt.
I used the following code :
QgsDistanceArea d;
d.setEllipsoid("WGS84");
qDebug()<< "...
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Calculate a straight or centerline of a polygon
I have drawn some roads as polygon and I wish to know if it is possible to calculate how long the roads are.
I imagine that somehow QGIS can figure out the centerline of a polygon and create or ...
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Calculating distance of a path/vector through multiple points in QGIS 3.16.3
I created a .csv file with coordinates to show a route between two locations where I live. I want to figure out the distance one would travel to arrive from one location(A) to another(B). With '...
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Measure an angle on an orthophoto or on a dense cloud
I'm currently working on QGIS 3..10.1, and I would to analyse my roof with UAV analysis. I have already made a dense cloud, an orthophoto and a DEM on agisoft metashape but now I would make few ...
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QGIS CRS WGS 84 problem with the scale and measurement
I have a problem with my map scale.
It shows 0:1 instead of proper scale.
I am not capable to make any measurements, as the values go wrong.
When I click on the measurement tool I get an error:
This ...
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Automatically updating feature area in the attribute table using QGIS
How can I write an expression to update the area of polygons and lengths of features automatically as well as the sum of the areas and lengths? I am using QGIS 3.16.7 and the data format is OGR ...
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Measure between two images in QGIS 3.18
I'm currently working on QGIS 3.18 in the area of geo-referencing. I have two orthophotos (they are same) but the first one is untreated, the second was corrected by differential GPS. I want to ...
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Measure distance in km of polyline in QGIS
As much as I have looked numerous times for how to measure vector polyline in QGIS I can not find the way. This seems like an easy thing to do but the answer eludes me. Dah!
After I have traced out a ...
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Calculating semi-major and semi-minor axis length of an ellipse in QGIS
I have a layer that contains ellipse-shaped geometries. The layer has projected CRS and there are also rotated ellipses in the layer. I couldn't find a tool or plugin related to semi-major and semi-...
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Showing measurement in OpenLayers 6 while modifying
I have this code.
I create class the name is MeasurementClass. this class used for overlays component creator, setting of html and configure style . this class can handle it.
class ...
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Measuring distance between points in one layer and related points in a different layer in QGIS
I have two point layers. One of biological records which has an attribute field for the SiteID that the species has been found at. The second layer is a Sites layer with a centroid location for that ...
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Measuring the sides of a polygon one by one
At the moment I am working on an OpenLayers project or rather I am learning on a project.
I stumbled upon a feature:
When you click on a polygon on the OpenLayers map and that plygon is selected and ...
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QGIS v/s MapInfo - Differences in Distance Measurements
Distance calculated in different software (MapInfo and QGIS) has given me differences in distance values. To be more precise, it's mostly happening when the distance is more than 25 miles. I doubt ...
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Measuring distance between two points on curve line in QGIS
I am using QGIS 3.10 version.
Image those two blue lines are points. How to measure the white line between those points?
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Measuring distance between two points using digital elevation model (DEM) and ArcMap
I have a number of points mapped on a digital elevation model (DEM). The points were mapped on the DEM based on their GPS location (latitude, longitude).
What is the best way to measure the distance ...
