Monthly Archives: August 2012

Paul Doherty's Research Page

Just a quick note to highlight Paul Doherty's new research page.  It includes:

  • Overview of his research
  • Publications list
  • Software & Datasets page, including links to MapSAR and discussion groups.
  • Linkspage with a SAR & GIS bibliography including the memorably titled
    • Heggie, Travis W, and Michael E Amundson. 2009. “Dead Men Walking: Search and Rescue in US National Parks.” Wilderness & Environmental Medicine.
    • And the humorously mangled:  Is, Information, Releasable To, and Foreign Nationals. “Search and Rescue Optimal Planning System ( SAROPS ).” Training 2.
    • And three articles it sounds like I should read soon:
      • Jobe, T.R., and P.S. White. 2009. “A New Cost-distance Model for Human Accessibility and an Evaluation of Accessibility Bias in Permanent Vegetation Plots in Great Smoky Mountains National Park , USA.” Journal of Vegetation Science: 1099–1109.
      • Miller, Harvey J., and Scott a. Bridwell. 2009. “A Field-Based Theory for Time Geography.” Annals of the Association of American Geographers 99 (1) (January 8): 49–75. link
      • Pingel, Thomas J. 2011. “Estimating an Empirical Hiking Function from GPS Data.” Sports Medicine: 1–3.

At Mason we're collaborating with Paul to test a Watershed-Distance model developed by his research group.  Based on 58 tests run so far by Elena Sava on MapScore, this simple model scores 0.55.  Not bad for a model that doesn't yet discriminate by category (or any other feature).  Elena just finished a multivariate model combining Watersheds with the more usual crows'-flight distance, and we will begin testing that soon.



A Brief Intro to Search Theory (2 of 4)

In the previous post, we began to build a theory of detection over time as the result of a very large number of independent glimpses.  By assuming the environment to be fixed for awhile, we moved all the environmental factors into a constant (to be measured and tabulated), and simplified the function so it depended only on the range to the target.

In this post we simplify still further, introducing lateral range curves and the sweep width (also known as effective sweep width).  We will follow Washburn's Search & Detection, Chapter 2.  (So there's nothing new in this post. Just hopefully a clear and accessible presentation.)

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