SaTScan 9.4 released, better than ever!

SaTScan is a program for detecting clusters over space, time, and space-time.  It is available for Windows, Mac OS X, and Linux. SaTScan 9.4 was recently released and it is better than ever!  The data import wizard now allows shapefiles to be read and and a graphing feature has been added to help examine temporal trends. Visit the link for a better look at the rundown of new features.

The Import Wizard now reads shapefiles.

In previous posts, I've covered the types of files you will need and how to aggregate data in preparation for importing it. Since version 9.2, SaTScan has had the ability to export *.kml and *.shp so that the most likely clusters can be viewed in GIS software. (Aside: Google Earth Pro is now free! https://www.google.com/work/mapsearth/products/earthpro.html)

Below is an example looking at clusters of low immunization rates in California from the journal Pediatrics. Free full-text: http://pediatrics.aappublications.org/content/135/2/280.full.pdf+html

In SaTScan, using lat/long coordinates, allows users to export to *.kml and *.shp.
Google Earth opens the *.kml automatically when a run is complete.

A few tutorials are being made, http://www.satscan.org/tutorials.html and sample data is available. Be sure to read the expertly written user's guide before running: http://goo.gl/rHg7M6. and the long and varied bibliography of analyses conducted with SaTScan: http://www.satscan.org/references.html

Update #1 (2/20/15)
Scan statistics can also be implemented in R's Spatial Epi Package and rsatscan.

Free Online Mapping Classes From PSU and Coursera

Course dates: Last updated on 12/16/2014

Penn State has an online Open Web Mapping Class for free using open source software.  The course materials are available at: https://www.e-education.psu.edu/geog585/ through a creative commons license. You can also take the paid version of the online course for credit.  Coursework includes QGIS, GDAL, OGR, GeoServer, TileMill, Openlayers, and OpenStreetMap.  Penn State also has several map-related classes on Coursera.

Coursera has at least six relevant classes to GIS, GPS, and more during this upcoming fall 2014 and winter 2015 sessions.  Please note some of the courses do offer different tracts that range from basic to technical in difficulty.  This fall and winter there are exciting course offerings!

Introductory

• Maps and the Geospatial Revolution, March 25, 2015 (Penn State)
• Geodesign: Change Your World, July 8,2015
• Or sign-up for future sessions, just click the drop-down for the date.  You will get an e-mail announcement

One course is on Geodesign

• Geospatial Intelligence and the Geospatial Revolution, January 14, 2015 

Intermediate-Advanced

• From GPS to Google Maps to Spatial Computing, Just finished, next session TBD (University of Minnesota)

Another is on GPS, mapping, and spatial computing

• An Introduction to Satellite Navigation, with an interactive Worldwide Laboratory using Smartphones, Just finished, next session TBD (Stanford University)

• If you have a programming background checkout Programming Mobile Applications for Android Handheld Systems, TBD (University of Maryland College Park).

Other-related

• Epidemics the Dynamics of Infectious Disease, TBD (Penn State)
• A small part of the course involves using GPS data generated over the course of a MOOCDEMIC or mock epidemic.

Also don't forget, ESRI does have some free and low cost tutorials for ArcGIS on their training page as well: http://www.esri.com/training/main.  Be sure to checkout Directions Magazine's articles and webinars for other opportunities.

If anyone else has any that they would like to share, feel free to write them in the comments section below!

Update #1:  Noteworthy addition:  ESRI is offering a free MOOC or massive open online course entitled "Going Places with Spatial Analysis".  Head over to the link below to signup for notification when registration begins, which is shortly: Going Places Signup / Start Page

Image Processing Using Orfeo Toolbox in QGIS

Satellite and aerial images are more than pretty pictures.  Each image contains a wealth of data that can be queried, modified, extracted, and visualized through simple and advanced techniques.  This blog entry will cover a few basic tools in the Orfeo Toolbox in QGIS.  Instructions for installing Orfeo Toolbox in the QGIS processing toolbox can be found be clicking here.  There is also a standalone Monteverdi 2 program.

Quick Background on Orfeo Toolbox
The toolbox, often abbreviated OTB, was created to promote the use of several French satellites.  Like many programs, the algorithms are geared towards popular satellites.  For more on its creation, visit: http://www.orfeo-toolbox.org/otb/about-otb.html.

In QGIS
After following the instructions above, go under "Processing" and make sure the "Toolbox" is selected. You will see Orfeo's tools grouped into what types of functions they perform.

Screenshot of Orfeo Toolbox in QGIS's Processing Toolbox

Feature Extraction, Identification, and Classification
Extracting features from imagery is an extremely powerful tool.  For example, roads can be extracted from imagery.  Edges of images and line segments can be detected.  They can a provide a quick unique source of data for areas large and small.  Click on any of the images below to get a closer look.

Extracted edges of buildings at a college campus.

Line segment detection: In this case the lines of a tennis court (and fencing).
The tan lines are generated by the software.

Line segments differentiating a road, sidewalk, and  nearby grass.

Images can also be searched for specific objects. to automate their discovery. Image classification, groupings based on spectral characteristics, whether supervised or unsupervised, is another post in itself.

Change Detection
Another important aspect of imagery is detecting changes over time, whether something is new, absent, modified, or (re)moved.

Left: Unpainted roof, Center: Roof painted red, Right: Change Detection of Roof

Documentation
Remote sensing and image processing are technical fields.  There is a significant amount of documentation (hundreds of pages) on the Orfeo Toolbox website. A shortened manual and a series of short practical exercises could help to expand its user base.  If you work in remote sensing and image processing, be sure to check out this fantastic resource!