Questions tagged [interpolation]

The estimation of values at unsampled points based on known values of surrounding points.

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Groundwater interpolation using kriging with external drift

I have a bunch of groundwater measurements that I would like to interpolate taking into account the ground elevation. For this, I was advised to use kriging with external drift. I have tried different ...
stray_dog's user avatar
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DCELL cell type is set automatically for raster after r.resamp.interp

After interpolation with r.resamp.interp with bilinear method DCELL cell type is set for raster. When I export it with r.out.gdal I get a precision loss error, as I export it as Float32 (PCRaster ...
Nikolay Yasinskiy's user avatar
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Finding interpolated value from raster data in PostGIS

I have a series of values that were computed for each cell on a grid on a given territory. Those values has been stored in a raster field in PostGIS (there are no missing data). I want to run a query ...
Thibault J's user avatar
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gdal_fillnodata strange artifacts

I'm seeing an odd artifact when using gdal_fillnodata.py. I have a raster (purple is no data, white and black are two different numeric values). Using a mask exactly corresponding to the no data ...
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Error in performing IDW interpolation in QGIS?

I attempted to use IDW interpolation for the current canvas and the basin shapefile. However, the number of rows and columns in the output raster size is 33000 by 46000, which is causing significantly ...
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LineString length obtained from shapely differs from actual real distance [duplicate]

I want to obtain the points of a LineString that are at a distance of 25m from the first point and from the last one of said LineString. I was doing some tests to check whether or not Shapely could be ...
Jon's user avatar
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Create heatmap polygons shapefile from a points shapefile for a variable in attribute table in R

The objective is to create heatmap polygons from a points shapefile named "df_sf" for an attribute "V1" in the shapefile and then export these polygons as another shapefile in R. ...
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How to show point data as a colored map?

Im doing one, I would say, simple analysis, but Im rookie when it comes to GIS, so I need help. So, I have data of CPT (cone penetration test) which our firm conducted over the years and within that ...
Marko Boričević's user avatar
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Problem with SAGA batch processing

I have a series of point clouds in LAZ format that contain points identified as ground. I want to interpolate these points with the Multilevel B-Spline algorithm of Saga GIS and export the clouds to ...
Gerardo Jimenez's user avatar
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TIN interpolation QGIS - Voronoi Polygons

I'm trying to interpolate 12 points in QGIS linear within a Voronoi Polygon using TIN-Interpolation created for the points. However,the extent of the raster layer only interpolates between the points ...
Gus's user avatar
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How to use Lagrange interpolation method for station lies between a grid?

I have rainfall data for a catchment from 1990-2020 in grid format. But my station of interests lies in the grid, how to apply the interpolation to that station. I'm not sure if I'm proceeding ...
Hydra's user avatar
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How to divide a geographic area into N latitude and longitude quadrants

I would like to get the NW1,NW2,...NWn and SE1,SE2,...,SEn lat and long coordinates of N quadrants starting from an area identified by 2 geographic points: NW and SE. I would like to write a Python ...
kiks73's user avatar
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Re-projecting an orthographic image to a equirectangular projection has some sort of problem. The poles are getting truncated. missing parameter?

Re-projecting an orthographic image to a equirectangular projection has some sort of problem. The poles are getting truncated. is there a parameter I am missing? Is there a difference between "...
Molly's user avatar
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Interpolating flood surface using Topo to Raster in ArcPy

I am trying to interpolate a statewide flood surface for NJ using Topo to Raster in ArcPy. I split the input points into 900 separate input point feature classes using 14-digit watershed boundaries. I ...
dejonra's user avatar
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Can't open IDW interpolation while I'm using QGIS 3.34

I can't open IDW and TIN interpolation. How can I solve the problem?
Kelvin的地理空間's user avatar
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Add missing values to raster data set [expand, not fill holes] in QGIS

I'm relatively new to QGIS and have run into the following problem. I am using a raster soil data set that was cut to the country border. However, since the cut was rough and my research area is set ...
lappelsien's user avatar
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TIN interpolation keeps discarding original values of sample and interpolates them [closed]

I'm trying to make a DEM in QGIS using TIN. I have a set of points with elevation data on one of the attributes. My problem is that when I generate the raster, the initial set of point values are lost ...
A rookie's user avatar
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Working on a manual NTv2 bilinear interpolation

I asked this on the Math Exchange, but I figured I'd also post it in here to see if I could get some insight from some GIS folks. I think it is a math problem, but maybe my process is wrong. Any ...
Tkbacon's user avatar
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Problem interpolating point shapefile QGIS

I've been having a lot of problems trying to interpolate some topographic point data from the coast of Japan. The data consist on regular separated points 10 meter apart. I've tried to interpolate ...
GeronimoP's user avatar
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Python: interpolate dataset to create a global map

I have a NetCDF dataset (this) with values for the world's oceans. The measurements are in the form of unevenly spaced points: Now I want to extract some values at specific locations. My problem is, ...
terauser's user avatar
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Interpolate a GeoJSON file [closed]

I have a GeoJSON file which consists of rainfall data in a location. I want to interpolate those point data in GeoJSON and make a raster file, and display in Leaflet map. How can I do this?
Srijit Sharma's user avatar
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QNeat3 Polygons do not finish calculating interpolation

I have been using QGIS for a couple of years and used QNEAT3 for the first time around one year ago. I never had any problem with it but, after some months not using it, I tried to use it again to ...
Jose Cáceres's user avatar
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Creating Raster from CSV in QGIS - Huge filesize

I am attempting to create a magnetic map of Northern Ireland using this dataset (https://www.opendatani.gov.uk/@geological-survey-of-northern-ireland/gsni-tellus-regional-airborne-geophysical-survey-...
Nemactual's user avatar
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vis.gam spatial interaction output as a raster grid instead of plot object

I am trying to create an object that can be put into tmap or another GIS platform from my model output. I created a model using the gamm4 package that has a spatial interaction term. See an example ...
megsruppUNBC's user avatar
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Minimum datapoints for Kriging

Are the datapoints (34) for this Kriging operation sufficient? Research Gate recommends > 30. [both -> here and here], while another source [-> here] mentions 30 to 50. All mention Webster ...
arkriger's user avatar
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Unable to get the road network distance between two points in PostGIS

SELECT sf.id, sf2.gid, SUM(ST_Distance( sfroads.geom, ST_LineInterpolatePoint(sfroads.geom_latest1, ST_LineLocatePoint(sfroads.geom_latest1, sf....
Badboy's user avatar
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3 votes
1 answer
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Create conical gradient around a point using R

I have a point on a map that I am simulating bird movements from. I'd like to create a raster grid around this point with a conical gradient, similar to the picture below. The idea is that the birds ...
srha's user avatar
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Coordinate-based interpolation of values in time series format

I have three different streamflow gauge station points along a river. For each point, I have streamflow values as timeseries. Between these station points (Red triangles on the map) I have additional ...
Husamettin Taysi's user avatar
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Using data for interpolation in Geostatistical Wizard of ArcGIS Pro

i do have soil temperature data (5 cm depth) from 1991 and 2021 for Germany, and wanted to interpolate the data for each year as a class of 3 seasonal months (winter = 12, 1, 2; summer = 6, 7, 8). ...
vaber32's user avatar
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Improving kriging results from transect data

I have estimates of fish density along transects from a lake and would like to extrapolate these estimates for the entire lake surface, using kriging methods. Based on information from here, here and ...
M.Teich's user avatar
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ArcPy IDW interpolation with LiDAR point cloud data

There are several questions such as 1, 2 etc on interpolation, but, when I implement the same procedure to calculate digital terrain model from point cloud I get an error: las_path = r"C:\Users\...
Nasa_Milla's user avatar
2 votes
1 answer
85 views

Switch begin and endpoint in profile graph - ArcGIS Pro

I created a profile graph in ArcGIS Pro. The TIF file that I use to create the profile, via the function "Interpolate Shape", contains the elevation in Europe. The line that I created starts ...
Foeke Boersma's user avatar
1 vote
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91 views

Convert a pixel-aligned grid to node-aligned [closed]

Given a regular grid of squares with sample points at their centres (a pixel-aligned grid), what would be the best way to interpolate to the corners of the squares (a node-aligned grid). I'm aware of ...
J.J. Green's user avatar
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Find and select local maxima on a raster

I'm trying in ArcGIS to obtain local maxima from a raster (for example a DEM) calculated with a circular sliding window of constant radius. Is there a way to pick up and select the local maximum ...
Marco Fioraso's user avatar
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2 answers
140 views

Bilinear interpolation of a matrix to extract Z at different locations [R]

I have that geoid heights (quasi-geoid model hBG18) in a form that matrix : library(tidyverse) Geo <- read.table("https://www.isgeoid.polimi.it/Geoid/Europe/Belgium/public/hBG18.dat", ...
C. Guff's user avatar
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Resample() function in R's terra package and the r.resamp.interp module in GRASS GIS yield such different rasters

Comparing the results from the resample() function in R's terra package (version 1.7-29), and the r.resamp.interp GRASS GIS module (version 8.2), I find differences in how they apply bilinear ...
Eden's user avatar
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RMSE in interpolation

I am doing interpolation for a chemical concentration in loamy soil across a very large arable land. I used simple kriging, IDW and EBK. The data distribution was skewed so I had RMSE of close 100 for ...
user223690's user avatar
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1 answer
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Spatial Interpolation of Point Layer with Count and Associated P-Value

Here's quick synopsis of the data I have. I have a dataset of just under 100 points with most points being coincident with several other points resulting in roughly 15 unique locations. Each point ...
TreeGIS's user avatar
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1 vote
1 answer
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How to make interpolation and contour for recording distances on images?

I have a question about interpolation and contours. In the images from the animal observation cameras, we would estimate the distance from the camera to the animal. In theory, we had the idea of ...
Tim Pirc's user avatar
1 vote
1 answer
43 views

Extracting points in a regular interval from TIN-Interpolation raster in QGIS

I had million of points with x, y and z. I could not filter them in QGIS in order to get them in an interval of every 0,9m. So what I did is TIN-Interpolation and I do have a raster now. How can I get ...
Ditila's user avatar
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0 answers
77 views

SAGA Close Gaps - using the mask parameter?

I'm trying to interpolate cells in a gap in a raster layer using SAGA's Close Gaps tool. It works fine when I don't use the mask parameter, but when I do, it fails to generate the layer. There's not ...
hmnoidk's user avatar
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2 votes
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Error with pycnophy R function from predicts library

I am attempting to use the pycnophy() function from the rspatial/predicts library. Upon prepping county level data with a "population" metric and running these data through the function, I ...
geoscience123's user avatar
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1 answer
140 views

Interpolate underwater quality data with QGIS as with Surfer with Kriging method [closed]

I'm trying to interpolate conductivity data form a coastal area about 4-6 square km from a series of 10-20 probe wells more or less equally distributed. I have access to a licensed Surfer and to QGIS ...
LoRaier's user avatar
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0 answers
63 views

QNEAT3 Iso-Area as Contours interpolation problem

I have a network of roads in district, and i want to make Iso-Area as Contours from Layer of points (schools). So, I have some problems with it. Firstly, I don't understand why these jagged contours ...
Sergey47's user avatar
3 votes
2 answers
151 views

Expand a given bathymetry / DEM through interpolation towards 0 depth at coastline polygon

I have a grid of a bathymetry of a fjord (grayscale in the image below). The grid doesn't reach all the way to the coastline (blue polygon) because it originates from sonar surveys where shallow ...
roble's user avatar
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1 vote
1 answer
42 views

Point Interpolation in ArcGIS

I have a set of data points in a CSV format. I want to create a contour map using the data points so I used IDW Interpolation in ArcGIS. But, when I checked the maximum value of the output raster, it ...
Hafidz's user avatar
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Interpolating missing pixels from land cover classification map

On Google Earth Engine, I created a classified land cover map based on a composite of images (spanning 2 years). It's a time series study so increasing the range of images (i.e. increasing to more ...
Linus AG's user avatar
1 vote
1 answer
174 views

TIN Interpolation in QGIS but with a predefined Delaunay triangulation

I have a set of points from which I am trying to perform a TIN triangulation. However, the algorithm for the triangulation (i.e. the resulting raster) creates triangles that I would like avoid for the ...
Tomas's user avatar
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0 answers
422 views

SAGA GIS - regression kriging

I have a problem with regression kriging in SAGA under QGIS. It gives me an error - could not execute the tool. I want to create temperature maps from data set of meteorologic station and DEM. I have ...
Lucie's user avatar
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473 views

IDW Interpolation taking hours and hours - is there a better way to configure the settings, or a better solution than the built-in IDW?

I have some USGS LPC data that has 221,593 points, with a basic square shape of 1km x 1km, with the upper left cut away as seen in the pic. This job took over 50 hours to run "Execution completed ...
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