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

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2
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1answer
417 views

How to obtain closest point of point over polylines layer in PostGIS 1.4 (without st_ClosestPoint)?

I´ve got a polylines layer (pipes) and a points layer (valves) and In Postgis 1.4 I would like to obtain the closest points but exactly on the closest polyline. In other words, i need to locate each ...
3
votes
0answers
305 views

Create a path following a road, interpolating from a set of points

I have several hundred vehicular routes within a city from which I wish to create shapefiles. These take the form of directions such as "From Green Street, turn left into Brown Street, Right into ...
3
votes
0answers
47 views

Soft edges for interpolation output

I've built the following heatmap using QGis 2.8.2's Raster->Interpolation feature. It looks almost the way I want: The background layer is Google Maps tiles by using the OpenLayers plugin. ...
6
votes
4answers
386 views

What are the most efficient Geographic Weighted Regression packages?

What are the most memory efficient open source packages for calculating a geographically weighted regression (GWR)? I am in a situation where I need to do a geographically weighted regression on a ...
1
vote
0answers
17 views

Measuring error of Spatial Analyst interpolation such as spline, nearest neighbor and kriging?

I am planing to use interpolation method using spatial analyst tool and I found several methods like spline NN and kriging. I know I can do interpolation using geostatistical analyst but some ...
0
votes
1answer
62 views

How to create soil-type maps using QGIS

I am trying to create a soil-type map of an area from point data using QGIS. I tried interpolating the data, since soil is continuous. I did this by allocating a number to each point type and then ...
0
votes
0answers
10 views

Kriging problem within ArcGIS Model Builder

I am creating a model that accepts in a .csv file and plots the XY points on a calculated field. The preferred interpolation method is Kriging, and when I try and update the Z-Value field, the ...
0
votes
2answers
112 views

Why do the range of values change when I export geostatistical layer to raster?

I did an interpolation of soil pH using 232 data points in geostatistical analyst with IDW, RBF and ordinary kriging. For all 3 methods, the range of pH values change (become smaller) after I export ...
0
votes
1answer
33 views

choice of number of neighbors in IDW

I am not so familiar with 'interpolation' math, albeit I grasp the underlying logic. I was wondering if there is a rule of thumb in the choice of the number of neighbor points to use in IDW ...
1
vote
1answer
37 views

Interpolation extent

the following pics will hopefully explain my problem. After interpolation an clipping the grid I get the result you can see on the pic. Next to the boundaries there are a lot of gaps caused by the ...
1
vote
0answers
29 views

How to interpolate a Raster DTM

I have a GeoTIFF DTM produced from Agisoft Photoscan at 0.05 m resolution. However the interpolation used by the program to remove the riparian vegetation has used points from the channel, thus ...
1
vote
0answers
46 views

Geoserver render interpolated polygons

First post here on the GIS forum, ill try to do my best explaining my situation. Im looking for solutions or pointers in the right direction. So, right now I'm experimenting with Geoserver. The data ...
2
votes
1answer
182 views

How to add an interpolation raster from the python console in QGIS?

I'm trying to add an interpolation layer based on an existing vector layer by using the Python Console (initially in the menu Raster/Interpolation), but can't find anything related in the ...
1
vote
1answer
67 views

What resampling method is used in gdal_merge?

I am using the gdal_merge python script to merge rasters that have slightly different, though similar, input resolutions. The documentation advertises that it can handle different resolutions, and in ...
0
votes
2answers
200 views

Store GPS trace with timestamps, then interpolate location by time

I'd like to: Load a 1-second interval GPS trace (not GPX) into PostGIS Then query the table at sub-second accuracy (about 5Hz), and get PostGIS to interpolate the location by time. Is this ...
1
vote
0answers
25 views

give importance weighting to sample points in an IDW-interpolation

I am trying to make an IDW-interpolation in arcgis 10.1. In my sample file i have points with the same x,y and z values. According the arcgis-resource-site, the points are considered duplicates and ...
0
votes
0answers
24 views

Thin Plate Spline interpolation

I am completely new to spline interpolation, and I want to apply Thin Plate Spline using the fields package in R, and after I have applied Tps then do leave-one-out cross validation. This is how my ...
32
votes
9answers
13k views

Open source methods for kriging?

I have a point dataset which I'd like to Krige, ideally using an open-source software package. If possible, I'd also like to choose the semi-variogram model during the process to improve the ...
2
votes
0answers
38 views

How to visualize Smoke Dispersion by interpolating point data

During the last weeks, I am trying to develop an application within my current working project, which aims to simulate smoke dispersion of fire incidents. Software used: ArcGIS for Desktop/Server ...
0
votes
1answer
70 views

IDW in R with cross validation

I want to perform IDW interpolation using R, and more specifically, using the idw command from the gstat package. Also, I want to use the optimal number of neighbors (point locations) and distance ...
1
vote
1answer
51 views

How to use gdal.FillNodata in python?

I am trying to use gdal.FillNodata in python on a ".tif" raster. The nodata value is set to -3.402823e+38. Here is my code : import gdal from gdalconst import * ET = ...
4
votes
2answers
200 views

Interpolate Temperature Using DEM

I want to "co-interpolate" temperature with DEM. I have SRTM 90m aggregated to 1km and I want to "co-interpolate" my DEM with points with temperature data. How do I do this? I am using ArcGIS 10.
1
vote
1answer
176 views

Interpolation grid for scattered data having (latitude, longitude) coordinates

I've got some scattered data in the form of (latitude, longitude, someParameterValue). I'm using inverse distance weighting interpolation method to interpolate them in a rectangular grid of pixels. ...
0
votes
0answers
22 views

Interpolating a set of GPS points on ellipsoid earth model

I have a set of GPS (latitude, longitude) co-ordinates along with the time at which the coordinates were collected. Additionally, I have the speed and the heading of the vehicle at those coordinates. ...
0
votes
0answers
21 views

Deriving RMS Error Interpolation Method in ArcGIS

Which is the best process for deriving RMS error for interpolation methods. I would like to compare which of the interpolation method in ArcGIS is best for my data.I need the procedure of determining ...
0
votes
1answer
33 views

Changing the origin of a Geotiff and resampling

I have georeferenced data from 1 to 10M resolution in GeoTiff format. I can use gdal to resample everything to 5M, but I would like to store the data so that rather than having an origin at a decimal ...
2
votes
2answers
57 views

Isolation and interpretation of vineyard multispectral data

I have 3 band multispectral raster imagery over a vineyard from which i have created a number of indices e.g. NDVI. The data is fairly high resolution (5cm/pixel) so shows a lot of along vine and ...
0
votes
0answers
35 views

Using Raster Calculator with Elevation Data from Contour Map

I am following this tutorial to attempt to determine flooding in the Gulf region based on estimated rises in sea level. I have taken topographic maps from the USGS and used to contouring tool to turn ...
3
votes
1answer
361 views

Can ArcGIS handle missing values to create a contour map?

I am trying to create a contour map for a waterbody. It turns out that in several locations there is no data. I just don't want to use the missing values as zero in ArcGIS because it would create ...
2
votes
1answer
585 views

Inverse distance weighted interpolation for categorical and/or binary datasets

I want to perform an Inverse distance weighted (IDW) interpolation to a series of points. However my data set can be categorical or binary and just like the IDW I want to interpolate the new values ...
0
votes
0answers
63 views

How to interpolate raster to get finer resolution?

I am working with precipitation raster layer. It happens the raster data to be in a resolution of 0.25 degrees grid. How could I interpolate those pixels to have a better resolution, say, a resolution ...
2
votes
0answers
38 views

Interpreting results of QGIS intepolation and Heat map from point shapefile

I have taken a step interpolation and heat map of the data point shapefile (building Centroid) with QGIS ver-2.8.1, as shown below. My question are: What is the difference of the two methods? How ...
1
vote
0answers
23 views

Coordinates interpolation for video frame synchronization

I'm taking an aerial video with gps coordinates. Here's the problem: the video is x frame at second, and the gps module gives me coordinates every second. So I've the coordinate of the first frame for ...
1
vote
1answer
91 views

Transforming Lat/Long NASA points into raster for ArcMap?

I have this irradiation file and I would like it to upload it in ArcMap in order to overlay it with other layers to do clips, intersections, etc? ...
3
votes
1answer
56 views

How to remove spikes from grid in SAGA GIS? [duplicate]

I tried to get a grid by interpolating LAS file using Ordinary Kriging. But the product grid has many pixels which values strongly stands out from average surface - I mean one pixel sinks nad spikes. ...
2
votes
1answer
58 views

Relationship between contour interval and spatial resolution of a generated DEM

If I have contour lines with interval say 10, 5, or 2 (etc.), and I generated a DEM from them, what is the relationship between between the contour interval and the resolution of the DEM? Irrespective ...
3
votes
1answer
145 views

Strange spatial interpolation results from ordinary kriging

I'm using Ordinary Kriging to interpolate a set of spatial data. I'm working on different sets which represent different days of measurement. I get good results, apart from one specific set. Will post ...
3
votes
2answers
96 views

Kriging values greater than the most extreme value of the input layer?

I'll admit I don't understand kriging to the fullest. Yet, I've read that the weights should add up to 1 as in IDW and Natural Neighbors. However, surrounding the biggest elevation points of my ...
0
votes
0answers
55 views

QGIS interpolation gives same value across the grid, what am I doing wrong?

Following this question, I've tried to use interpolation in QGIS to get a sense of the topography of a map based on about 3500 track points with elevation. The elevation ranges between 213 and 353 ...
1
vote
0answers
23 views

Strange interpolation with natual-neighbor metod

I have base shape file and try to use different interpolation methods to get image like this: This layer is constructed using point to raster conversion. Generally, interpolation methods as idw ...
2
votes
1answer
70 views

TIN Interpolation in QGIS creates weird lines?

I am using TIN Interpolation to interpolate point features based on their cost attribute (value is between 0 and 5000). Graduated symbology creates something like this: However when I am using TIN ...
2
votes
0answers
33 views

Expand data set by interpolation

I have a data set that is classified into 7 landcover classes. I've been asked to expand this data set to a new boundary. My question is How can I interpolate my existing data out to meet the new ...
2
votes
1answer
61 views

How to interpolate line Z from sparse attribute values

I have a series of end-to-end connected 3d lines which I'd like to add elevation values for all vertices on the lines which are currently null or 0. How to accomplish this? In the following image ...
3
votes
1answer
638 views

“Topo to Raster” tool for QGIS?

is there any analogue of the ArcGIS "topo to raster" tool in QGIS? I need to creates surfaces from shp for some cases from points and for some from lines and this instrument is very convenient.
1
vote
1answer
53 views

Interpolating points conditionally

I have two sets of data. One comprises all home sales in a given area, where each data 'point' is actually a polygon representing the lot that was sold. The other set comprises arrests made in the ...
2
votes
1answer
31 views

Why does the use of barrier lines significantly increase idw processing time?

The IDW tool's documentation states that using barrier lines will significantly extend the processing time. It does not explain why this happen. Is anyone able to provide an insight into the inner ...
2
votes
1answer
571 views

Ordinary kriging tools available in ArcGIS?

I have been using Geosoft's Target to interpolate X, Y coordinates then use them to create grids using ordinary kriging. I am now working with ArcGIS which I am new to and can't seem to be able to ...
1
vote
1answer
202 views

Can we create topographical map of private land using GPS elevation data?

Is there a way to create a relatively precise topographical map of a private land using GPS elevation data? As the land is a little bit over 100,000 square meters, the available regional topographical ...
6
votes
3answers
826 views

Spatio-temporal block kriging with R package gstat?

In the documentation of sp I saw that the coords argument of the SpatialPolygons function only accepts 2 columns. Is it not possible to create 3-dimensional polygons? I am doing spatio-temporal ...
1
vote
1answer
65 views

Unit of measurement from standard error prediction map

I am performing an ordinary kriging analysis and came out with the prediction standard error map. I would like to know the units of such map. Can anyone help me?