[Taxacom] Inappropriate accuracy of locality data

Frederick W. Schueler bckcdb at istar.ca
Tue Nov 30 17:55:55 CST 2010

On 11/29/2010 4:54 AM, Bob Mesibov wrote:

> A typical 'consumer' handheld GPS unit gives a location with an accuracy of plus or minus 10-20 m under typical field conditions. In hilly or densely forested country the accuracy may not be this good. The very popular Garmin E-Trex has 15 m RMS accuracy, i.e. about 2/3rds of the time the GPS location will be within 15 m of the real position - under favourable conditions.

* this has been a very interesting thread, and I'll read it in detail 
when things are less frantic here, but I'll just say how I deal with 
accuracy/site size in my database.

ACCURACY is a string field which is initially loaded with the presumed 
accuracy of the source data, in the case of a handheld GPS such as the 
eTrex "25m waypoint." If an area larger than this is visited, the 
leading number is increased in size, and the orientation of the site is 
described - "100m site" for a more-or less circular wandering, or "75m 
downstream," "10km along County Road 19" or whatever is the appropriate 
description if the wandering was along some feature or otherwise linear.

The reasoning behind this is that this gives a raw diameter for the 
collection in the measurement, while providing guidance for those hoping 
to replicate the visit to a site, without having to have a separate 
FOOTPRINT field that would complicate data entry.

           Frederick W. Schueler & Aleta Karstad
Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm
Thirty Years Later Expedition - 
Longterm ecological monitoring - http://fragileinheritance.org/
Daily Paintings - http://karstaddailypaintings.blogspot.com/
      RR#2 Bishops Mills, Ontario, Canada K0G 1T0
    on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
     (613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/

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