Monthly Archives: April 2015

Whitebox Geospatial Analysis Tools v. 3.2.2 Released

Whitebox Geospatial Analysis Tools v. 3.2.2 Released.

http://www.uoguelph.ca/~hydrogeo/Whitebox/download.shtml  (Whitebox GAT download link)

Whitebox Geospatial Analysis Tools v. 3.2.2 has been released by Prof. John Lindsay.  A lot of interesting and useful tools have been added in this new version. See below for a partial list of new features:

  • LAS files can now be rendered based on the Classification, Scan Angle, and GPS Time in addition to Elevation and Intensity. This is on top of several other improvements that have been made to the display of LAS file data in Whitebox GAT.
  • Added Conditional Evaluation tool (if-then-else statement). I really like this tool and now wonder how it was that I managed to get by without it.
  • Added a PickFromList tool, which outputs a raster with the value from a stack of rasters based on an input position raster.
  • Added LowestPositionHighestPositionPercentEqualTo,PercentGreaterThan, and PercentLessThan tools for working with raster stacks, i.e. lists of overlapping raster images.
  • Added a tool to create histograms based on the elevations, intensity, and scan angles within a LiDAR (LAS) file. It will also output the percentiles of the distribution, e.g. 95th percentile of elevation.
  • Added the AddPointCoordinateToTable tool, which can be used to add the x-y coordinates of points within a Point type ShapeFile as fields within its attribute table.
  • Added a tool to filter the points in a LiDAR (LAS) file based on a threshold in the absolute scan angle. Currently the output is a shapefile of mass-point shape but eventually we would like to have it write to a new LAS file.
  • The Merge Points Files tool was replaced with the more general Merge Shapefiles tool, which works with any ShapeType.
  • Added the FindLowestHighestLocations tool, which will output vector points corresponding to the lowest and highest points in a raster. This has already come in handy several times.
  • Added ExtractRasterValuesAtPoints tool for extracting the cell values of each image in a raster stack corresponding to a set of vector points. Values are placed within the vector attribute table.
  • Added DeleteSmallLakesAndExtendRivers tool, which can be used to remove small lakes (polygons) in a vector drainage network and to extend the associated river network (intersecting polylines) into the interior of the lake. I created this tool in response to an interesting question asked over on the GIS Stack Exchange: http://gis.stackexchange.com/questions/116718/alternative-to-delete-polygons-and-extend-lines-of-production-mapping.
  • Added a Long Profile From Point tool, which can generate one or more longitudinal profiles for the flowpaths issuing from a set of vector points.
  • Modified the Mosaic With Feathering tool to handle RGB images in addition to continuous scale rasters. At the moment, this only works for the nearest- neighbour mode. I’m not sure why I didn’t do this earlier.
  • Added Image Stack Profile tool to create a line graphs for a set of vector points through an image stack, such as multi-spectral satellite image data. This can be handy for visualizing the spectral signatures of individual pixels.
  • Added a Simple Region Grow tool that will perform a very simple region grow segmentation of pixels in an image stack based on a specified threshold. I’d like to continue development in this area and eventually include a full object-based image segmentation.
  • Added parallel implementations of the D8 flow pointer and accumulation algorithms. At the moment this is really an experimental tool that is not intended for widespread use but there is more to come, including parallel versions of all the flow accumulation algorithms.
  • Fixed a bug in the Hillslopes tool.
  • I’ve added a whole suite of tools to the Elevation Residuals toolbox for performing multi-scaled topographic position analysis. This includes modified tools for calculating difference and deviation from mean elevations using an integral image approach that is extremely computationally efficient, even with large search windows. It also includes the Local Topographic Position Scale Signature and the Maximum Elevation Deviation tools. Combined with the ‘customRGBScript.groovy’ script, these functions allow for the creation of some spectacular multi-scale topographic position visualizations. See: https://whiteboxgeospatial.wordpress.com/2014/12/25/a-new-form-of-multi-scale-topographic-position-visualization/ for examples.

Google Scholar Button for Chrome

https://chrome.google.com/webstore/detail/google-scholar-button/ldipcbpaocekfooobnbcddclnhejkcpn

This extension adds a browser button for easy access to Google Scholar from any web page. Click the Scholar button to:

– Find full text on the web or in your university library. Select the title of the paper on the page you’re reading, and click the Scholar button to find it.

– Transfer your query from web search to Scholar. Press the Scholar button to see top three results; click “full screen” in the lower left of the popup to see them all.

– Format references in widely used citation styles. Press the quote button in the popup to see a formatted reference and copy it into the paper you’re writing.

scholar

REDD+ for the Guiana Shield

Technical Cooperation Project

LidarBlog.com

Dr. Qiusheng Wu @ SUNY Binghamton

Writing Science

How to write papers that get cited and proposals that get funded

GIS In Ecology

Providing Training, Advice And Consultation On The Use Of GIS In Ecology

metrhispanic

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GeoAcademy

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Scientia Plus Conscientia

Thoughts on Science and Nature

r4hydrology

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Karl Hennermann

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GIS and Science

Applications of geospatial technology for scientific research and understanding.

GISblog.com

GIS, Mapping, Remote Sensing, Geodata, Geospatial news

Whitebox Geospatial Analysis Tools

Open-source GIS development and spatial analysis with Whitebox GAT

TopoToolbox

MATLAB-based software for topographic analysis

Anything Geospatial – AnyGeo

Dr. Qiusheng Wu @ SUNY Binghamton

GeospatialPython.com

Dr. Qiusheng Wu @ SUNY Binghamton

Another GIS Blog

Dr. Qiusheng Wu @ SUNY Binghamton

ArcPy Café

Get all your ArcGIS Python Recipes here!

Planet Python

Dr. Qiusheng Wu @ SUNY Binghamton