Douglas Argos-Filter Algorithm

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• What's New in v.8.50
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What's New!

What's New in Version 8.50!

This version (8.50) of DAF differs from the prior distribution (version 7.03) in two ways: 1) great-circle distances are calculated using the WGS84 spheroid, so distance calculations may differ by a fraction of a percent; and 2) the method of choosing between the Argos primary and alternate location solutions is greatly improved (see the MEE paper above).  Differences between the filtered outputs of Version 7.03 and 8.50 would likely be few and/or qualitatively inconsequential, so don’t be overly concerned if you’ve used and published your studies using prior version(s).

What's New in Version 7.03!

1. Optionally installs Argos tracking data (points and vectors) into the NASA World Wind display software.  World Wind is similar to Google Earth in many respects, offering some advantages and some disadvantages.
2. Unique colors are defined by the user for each animal so the point-icons and vectors that are displayed in Google Earth and/or World Wind are easily distinguished in composite displays.
3. User can change (scale) the size of the date annotations that are displayed next to the locations in Google Earth.
4. The Google Earth icons (locations) are time-stamped, so they can be temporally animated using Google Earth Version V4.0.2 (beta) or later.
5. The cost-estimate subroutine more closely simulates the actual CLS America (Service Argos) invoice charges.
6. The location filtering logic was NOT changed from that of the prior version (v7.02).

What's New in Version 7.02!

1. Google Earth files are created for each animal and each filtering variant.  Drag-n-drop the KML files onto the Google Earth desktop to quickly evaluate the filtered results.
2. ArcView Project files are created for each animal that simultaneously display all Argos locations based on all filtering variants.
3. A rough estimate of Argos costs (using the new 2005 Tariff Schedule) is printed to the SAS listing.
4. The detection and removal of redundant overpass data is elaborated to possess greater sensitivity.
5. The LINE variable is now unambiguously unique for every record within each output data set.
6. Length of the ANIMAL-ID variable can be up to 25 characters.
7. Defining your PC directory pathnames and filenames is simplified.
8. Defining your PTT deployments is accomplished using an external ASCII text file.
9. An external ASCII text file is available to manually override the choice of primary or alternate location for one or more specifically identified overpasses (records), or to remove problematic overpasses entirely.
10. A new option CROSSVAL is implemented that lets the user chose between a 1-stage or 2-stage procedure when the algorithm chooses either the primary or alternate location.  Previous versions always used the 2-stage procedure, but it was found to be less reliable for animals that don’t move large distances (hundreds of kilometers) between locations.