Spatial Analyst is a extension within ArcGIS that provides a range of spatial modeling and analysis tools.
2
votes
1answer
320 views
Spatial Analyst tool Look up but in ArcView3.2
Is there any option how to do a Spatial Analyst tool "Look up" operation from ArcGIS 10 in ArcView 3.2?
I have a grid with attributes and need to "extract" values from the table field (values from ...
7
votes
3answers
392 views
How do I create a raster randomly choosing a cell value from 2 or more overlapping rasters?
I'm using Arc 10. I want it to combine multiple rasters into one, always choosing randomly from the values of overlapping cells. I have an image that may explain this better:
5
votes
2answers
777 views
Can shaded relief be “blended” with DEM colour ramp in ArcGIS to produce a more visually dramatic result?
Not being able to use true transparencies with ArcGIS colour ramps where only solid colours are allowed has me always wondering about how to improve the look of the surface in my maps without ...
4
votes
1answer
215 views
How to create a field with a specified slope projecting from a 3D polygon
Im trying to figure out how to create a elevation raster from a known location (3D polygon) that projects at a specified slope (1%) for a specified distance(1-2 km). Does anyone have any idea how to ...
5
votes
1answer
208 views
How do I get the upstream distance to all points in a DEM from a single downstream point?
I want to get the upstream distance to all points in a DEM from a single downstream point. The goal is to create a "downstream distance to a point grid". This then would allow me to create "distance" ...
6
votes
2answers
470 views
What are best practices to compare densities and locations between two sets of points?
I have two sets of point shapefiles. They represent two different customer groups for a retail store. Shapefile A represents online customers, Shapefile B represents in-store customers.
What I ...
4
votes
1answer
1k views
How do I add a hyphen to the Field Calculator to merge 2 columns?
I am trying to build a field calculator expression to merge two columns into one. I am looking for the word that makes it a range.
Example: I have 2 columns in elevation, From and To. I want to ...
1
vote
2answers
506 views
arcpy.sa.Viewshed with OFFSETA
This is using ArcGIS10 arcpy with spatial analyst.
I need to call Viewshed, but with an observer height set. I have tried using a Z-aware point feature set, but that only throws an error. I am ...
0
votes
1answer
161 views
Specific Spatial Analyst tools failing while running extension using ArcGIS server
I am having having trouble running ExtractValuesToPoints on a remote server machine running ArcGIS Server (with ArcInfo and Spatial Analyst installed). It fails and throws a standard COM error. I have ...
5
votes
1answer
438 views
Are special interpolation techniques required for weather data?
I've downloaded a series of weather observations from the local weather agency - it comprises around 1,000 points spread non-uniformly across Australia, with a greater density of points located near ...
3
votes
1answer
403 views
Strange Behavior in Focal Statistics
I am trying to calculate the maximum value in a neighborhood on a raster using the Focal Statistics tool for Spatial Analyst in ArcGIS 10. Using python, I loop though several different radii, with ...
14
votes
4answers
1k views
Where can I find examples of fuzzy logic applications in ArcGIS?
The last ArcGIS version (10) includes two arctoolbox tools for fuzzy logic (Fuzzy Membership, and Fuzzy Overlay). Does anyone know where can I find some examples showing how they can be applied?
...
7
votes
3answers
713 views
How to cluster points based on a kernel density?
I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
3
votes
2answers
220 views
Is there a way of doing a statistical analysis of buffers?
I am doing a buffer analysis of incinerators and looking at the output areas within those buffers, is there a way of doing a statistical analysis of several buffers to see if there is a significant ...
5
votes
1answer
226 views
How to find upstream - lateral and downstream zones around urban areas?
I've a DTM and a shapefile of built-up areas. For a fire risk model, I've to find (within a defined buffer zone) two zones around built-up areas: one that is above/higher and lateral and the other ...
1
vote
3answers
429 views
What other tools can complete this exercise besides ArcGIS Spatial Analyst?
excel spread sheet here
The objective in the exercise is to determine how many public computers are available per person as a result of spatial distribution of libraries and people.
Part 1: Grid of ...
1
vote
3answers
1k views
Calculate XY Coordinate with “CalculateField” tool
I used model builder to build a model which can calculate the XY coordinates
and it's perfect!
However, when I export it to VBscript and run it in VBA it crashes....
The error happens at
...
5
votes
1answer
5k views
creating a dem from contours
I have a large set of contours that I received broken down into several different subsets. I have merged most of the subsets together creating a larger set of contours in three different files. I have ...
4
votes
2answers
1k views
How can I compare two point shapefiles that contain lat/longs and compute distance?
Greetings everyone, I have 2 sets of point shapefiles in ArcGIS (group A and B), each set has around 1000 entries that contain lat/long. What I want to do is compare Group A against Group B and figure ...
4
votes
1answer
290 views
When merging two DEMs, do they have to be in the same pixel bits?
I have a simple question. I have 2 different Digital Elevation Modeling (DEM). One is the state DEM and has 30m and has 16 pixel bit. I have a couple of smaller DEM that has 30m but they have 32 pixel ...
2
votes
1answer
322 views
How can you make RasterToASCII_conversion observe environment setting output cell size?
I have two rasters (an ESRI grid and an IMAGINE image) that differ in projection, extent and cell size. I want to convert the IMAGINE to an ASCII, and want it to have the extent, cell size and ...
2
votes
1answer
523 views
Solar radiation calculation from GTOP030 DEM image
Can you help me to calculate solar radiation from GTOPO30 DEM image at the 30 m spatial resolution. I'm trying to do this many times using spatial analysis-solar radiation calculation tool in arcgis. ...
2
votes
1answer
626 views
How do I know if the DEM has z values?
How do I know if the DEM contains z-values ? By looking at the DEM's layer properties and it does not mention the z values. I then add it to the ArcScene and tried to find it..nothing...
It only ...
4
votes
3answers
3k views
Find the nearest raster cell value based on a vector point
I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
0
votes
0answers
543 views
Watershed / drainage network analysis; floating point or integer raster for input?
I am a little desperate to find a solution to my problem. As I have detailed in this post I am unable to create a detailed drainage network (and catchments) from high resolution LiDAR data.
I think ...
13
votes
6answers
3k views
Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?
This is not the first time I've stumbled over this issue; it seems that I am unable to generate a correct drainage network model and the resulting catchments from full resolution (1m cells) LiDAR ...
3
votes
2answers
3k views
How do you set OFFSETA for a Viewshed in ArcGIS10?
How do I calculate height when attempting to do a viewshed analysis in ArcGIS10?
I am able to create a viewshed analysis from a poly point file, however I need to calculate for the 80ft to 100ft tower ...
2
votes
0answers
431 views
Spatial Analyst Cell Statistics seems to give the wrong answer in ArcGIS 10.0
I have a script that calculates standard deviation for a list of grids using the Cell Statistics function in Spatial Analyst for ArcGIS 10.0 The syntax is this:
stdevGrid = ...
4
votes
1answer
3k views
Thiessen Polygon delineation within a Feature
Greetings!
I am trying to create Thiessen (Voronoi) polygons, based on points within a defined shapefile extent.
The output should be inclusive to the feature. The output I receive now is the ...
2
votes
3answers
206 views
Trying to make the private land white overlay hillshade but
I'd like to have anyone's feedback on this draft map I created. Tried to make the private ownership white but since it's RGB is not near to 255.
I've seen someone created this map similiar to it and ...
4
votes
1answer
915 views
Processing time using ArcGIS Hydrology toolbox tools in standalone Python script vs. ArcCatalog
My question is: what might cause the ArcGIS 9.3 Hydrology Toolbox Snap Pour Point and Watershed tools to run significantly slower in a
Python script versus manually running the tools in ArcCatalog ...
4
votes
2answers
4k views
NoData in ArcGIS Spatial Analysis
When using Spatial Analyst I regularly have issues with NoData values cropping up in the data. Various tools appear to introduce NoData values regularly. These values then cause issues with other ...
3
votes
2answers
487 views
interpolating values within a certain distance of points
Let's say I have a set of points representing bridges. I want to create a kind of "heat" map that would highlight areas within my study area that has many bridges in good or bad condition. I have a ...
6
votes
2answers
725 views
Process a raster with multiple geoprocessing tools in arcgis 10 using python - flow between processes
I'm writing a short python script that includes processing rasters with different geoprocessing tools in ArcGis 10, for example, the three processes below, is this best way to use multiple tools ...
3
votes
1answer
667 views
Checkout Spatial Analyst extention, ArcObjects code
Update
After investigating more closely the CODE 2 sample below (at the end of this post), it does check out spatial analyst (sa) extension, however it does not reflect it in the Tools>Extensions ...
5
votes
2answers
675 views
Using an integer variable in where-clause in arcgis python script
I've seen some questions on this, but there seem to be many different answers... and none have seemed to work. I'm trying to include an integer variable in the SQL where-clause of a tool like this ...
3
votes
3answers
658 views
How do you produce a output table containing distances between mineral grains at various azimuthal directions?
I am using ArcGIS 10, the newest version and I am a senior at Western Carolina University and working on my senior thesis and the data set in which I have are images of mineral thin sections all ...
1
vote
0answers
551 views
two results of IDW in ArcMAP are different
i added the following points to ArcMAP using "Add XY Data".
x,y,z
7,39,117
27,17,122
27,61,123
46,36,136
52,14,138
55,46,141
56,56,137
65,24,144
65,36,145
Changed raster output size in "options" ...
4
votes
2answers
411 views
comparing two TINs
i have the following two files:
1) LiDAR las file1
2) Let's give it a name LiDAR las file2, contains the same file1 data, where number of points randomly removed.
So if file1 contains X number of ...
6
votes
2answers
351 views
Recommend text for Spatial Analyst? (ArcGIS)
Does anyone have a recommendation for a good reference/tutorial(s) on Spatial Analyst? The most recent I can find are from early to mid 2000s. Or has SA simply not changed much in 7 years? Thanks, ...
3
votes
1answer
1k views
rmse between two rasters step-by-step
can anyone show how to calculate the RMSE (root mean square error) between following two rasters step-by-step and discuss on the obtained results' min and max values, and how to interpret it. Thanks a ...
6
votes
3answers
3k views
Clipping a raster using a polyline or polygon
I have a large raster created from values that cover the whole United States and Alaska which are both polygon and polyline features, this raster was caluclated using Spatial Analyst IDW ...
5
votes
2answers
142 views
Monitoring programmes
I am not sure if it is a right place to ask this one but let me try.
Monitoring programmes are known for various targets and for various spatial levels.
They may include regions, countries or even ...
6
votes
7answers
2k views
Extract raster values at points
How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.
2
votes
3answers
932 views
How do you use Spatial Analyst Geoprocessing functions in ArcObjects in ArcGIS 10?
I'm trying to run some geoprocessing functions in ArcObjects. Some of the tools I want to use are part of the spatial analyst extension. In 9.3.1 it was fairly straightforward to follow the ...
7
votes
5answers
1k views
What type of interpolation should I use to visualize metal detection survey data?
I have about 500,000 points collected in a linear grid pattern over a 1 km2 area. The points were collected as part of a metal detection survey. Each point has X,Y and Coil Response mV (min -675.38 ...
1
vote
2answers
5k views
How to calculate Raster Area per Polygon?
In ArcMap, I have a raster file that contains 6 classes of landcover and a shapefile that is the census data (OA boundaries and their population).
I want the area of each class in each OA? For ...
9
votes
4answers
754 views
Are there any open source tools to detect and fill sinks on a DEM?
Are there any open source or inexpensive tools to detect and fill sinks on a DEM? ESRI Spatial Analyst is just out of my price range.
