Questions tagged [analysis]

The process of extracting geographic, statistical, geometric, or scientific information from one or more related collections of GIS features and data.

32 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5
votes
0answers
63 views

Using the height of river to approximate its extreme flood boundaries - terrain analysis in QGIS?

Using QGIS I'm trying to analyse an area/DEM with this criteria: - heights 10 meter above the river-centerline in both sides of river. I can do it with the calculation of contours (2m) from DEM and ...
3
votes
0answers
1k views

Performing Multicriteria Analysis Using Distance Along Road Network?

There is the possibility that I will be working on a project which will look at thousands of properties in a region and measure their accessibility to different services (schools, parks, hospitals, ...
2
votes
0answers
44 views

How to automatically compare two aerial photographs with a GIS with regard to certain features?

At present, we are trying to automatically record the new use of land by buildings by systematically comparing aerial photographs (e.g. 2007 farmland -> 2008 warehouse). For this purpose, high-...
2
votes
0answers
326 views

how to calculate cumulative cost of movement, accounting for wind direction, in R?

I am trying to reproduce the calculation of the duration of sail-powered navigation as described in an academic article (http://www.tandfonline.com/doi/full/10.1080/15230406.2017.1403376), but using R ...
2
votes
0answers
36 views

Working with intersecting polar grids

I'm having some trouble figuring out the best way handle some GIS data. I want to analyze pollution from specific sites at specific points. I have a list of sites I'm interested in all across the ...
2
votes
0answers
439 views

Performing Raster Algebra and Multicriteria Analysis using FME?

I'm trying to use FME to do some raster algebra for some Multi-Criteria Analysis. At the moment, I have three rasters, all with the same extents and resolution: Slope, Hydro, and Infrastructure Mask. ...
2
votes
0answers
694 views

How do I create a leader line for a label in my bar graph in ArcMap?

I am displaying a bar graph of various tornado watches and warnings along with the actual tornado touchdowns themselves. Since the tornado touchdowns are such a small number compared to the large ...
2
votes
0answers
1k views

Mean coordinates in QGIS

I am using QGIS v 1.7.4 for MAC and I am trying to calculate mean coordinates for a set of points using ftools. To calculate my result I am going to Vector -> Analysis tools -> mean ...
1
vote
0answers
28 views

Vector to grid - Computing statistics by grid cells

I have a vector point data from drifting buoys (speed, direction, sst, slp) that I want to analyse in a grid. What are the right tools for this? Example of my points data below. Each point has the ...
1
vote
0answers
319 views

Standard Method to calculate Average Moving Speed from Times & Coords?

...I wasn't sure if this question was best suited to GIS, SO or Math, so after reading GIS Topics I decided to ask here, but I'll relocate if necessary... :-) I'm working on automating various ...
1
vote
0answers
49 views

Road Network Accessibility

I am working in qgis with 3 layers: one is road network and other is hospitals and locations of accidents , later two layers are as points, I want to figure out what accident location (points ) are ...
1
vote
0answers
22 views

Are tesselation patterns an effective way of covering a shape?

I am using Facebook place search to explore business pages on Facebook. If I input a longitude and latitude into facebook's GraphAPI, I can search within a given radius for facebook business pages. ...
1
vote
0answers
79 views

Is it possible to combine buffer zone analysis with time series analysis in QGIS?

There is a multitemporal analyzer in QGIS where it is possible to do a buffer zone analysis combined with time series analysis, where there are two layers an input layer and a target layer and the ...
1
vote
0answers
93 views

How to do regression analysis in SAGA for topographic correction

Currently I am trying to do the topographic correction using C-Correction. I would like to know if there is a way to do the regression analysis between L (uncorrected reflectance of each band from ...
1
vote
0answers
476 views

How to delineate a zone of slope break

I have a DEM of a region and want to delineate about a half-mile region at the base of hills (e.g. an area where the slope changes from steep to shallow). I ran the slope analysis tool and it kinda ...
1
vote
0answers
45 views

Analysis of concentrations

I process images of trace gases concentrations distribution over the layer of atmosphere. I need to analyse values of concentrations, rather detect so-called "background" values and "extremal" ones ...
1
vote
0answers
197 views

Calculating spread of invasive species using ArcGIS for Desktop?

I have ArcGIS Desktop Advanced and so far have completed the following; Used Supervised classification on a satellite image to identify the invasive species with field verification. I have converted ...
1
vote
0answers
767 views

How to calculate the average point spacing for a layer of points in QGIS?

I have a set of points and want to calculate the average point spacing for further analysis. ArcMap has the 3D Analyst Point File Information for this but I'm searching for an alternative in QGIS. ...
1
vote
0answers
131 views

how to use line feature as stops input in network analyst?

I'm trying to build a certain route with network analyst on a Network Dataset. As an input to create the route I want to use line features. I am trying to do this with network analyst in ArcGIS 10.0 ...
1
vote
0answers
142 views

Get pixel values ascii 50 files

I'm working with photos from a camera. The camera is arranged to take NDVI values instead of RGB for each pixel. I have several folders with 50 pictures in each folder as '*.asc' files the pictures. ...
1
vote
0answers
120 views

How to produce a simple ZTV/ZVI in openWind?

I'm struggling to get to grips with openWind. I need to produce a ZTV showing a 5km radius around the chimney of a proposed industrial development. I'm not sure of the height of the stack yet but for ...
1
vote
0answers
429 views

network based interpolation methods, which one could I use?

I need to interpolate traffic data consisting in raw number of vehicles passing across certain points, where counters are. It is evident I haven't a uniform distribution of points and values about ...
1
vote
0answers
61 views

Analyse effect of groups on raster maps

I work with a mechanistic model that uses climate data to simulate some specific output for different time steps and spatial locations. Now I want to investigate the effect of different climate data ...
1
vote
0answers
394 views

Divide polygon evenly based on lines and intersection points

I have this purple polygon illustrated in the figure below. I would like to split the polygon so that each line segment (green) split the polygon evenly with the surrounding line segments. A line ...
1
vote
0answers
2k views

Error #010067 when running spline interpolation

I am attempting to run a spline interpolation on a point dataset of 585 features in ArcGIS 9.3, using the spatial analyst toolbar. The dataset holds only latitude, longitude and abundance attribute ...
1
vote
0answers
388 views

GIS Maximum area coverage problem

I want to find optimum antenna location for an area. Every antenna can cover an circular area. These areas diameter is 750meter. So how can i find minimum number of antennas and locations. NOTE: I use ...
1
vote
0answers
100 views

3D tool for a visual analysis

Given a 3D mesh I need to visualize and analyze properties and elements generated from the object such as: tensors coplanar/similar elements ( coplanar faces, aligned vertices, etc etc, 3D geometry ...
1
vote
0answers
137 views

How to relate Slope map and Curvature map so as to have in the end PERCENTAGE PROBABILITY MAP?

i am trying to deal with road detection this last month. So i am working with particle filtering that produces particles, that means possible targets(to my case cars)/points, with hidden information ...
1
vote
1answer
2k views

Extract values from raster by using polygons

I am working with multiple raster files that cover all of united states. The file format of the rasters - GeoTIFF. I have around 100 geotiffs that I need to process. Then I have another shapefile with ...
0
votes
1answer
40 views

Analysing landuse data in a buffer layer

In my project I want to analyse the landuse around some points within a certain radius. So I created a buffer around my points but I have no idea how QGIS could probably tell me what different ...
0
votes
0answers
40 views

Network Analyst takes so long

Is there some kind of limitations of number of features when we work with Network Analyst in SDE ? My net has 170.000 features, is it a problem ? Because it take at least 6 hours to finish the "Build ...
0
votes
0answers
159 views

GRASS 7.3 r.fill.dir Does Not Create Output Raster

I am running GRASS 7.3 on Mac OS X El Capitan (2.9GHz, 8GB RAM). I have had to disable SIP in order to run it, but it works. I am hoping to perform some hydrological analyses on a few DEMs. My DEMs ...