# Douglas Argos-Filter Algorithm

Douglas Argos-Filter Algorithm

## Detailed Description

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).