Perhaps each of you with concerns regarding coordinate accuracy have already
considered this option, but have you thought about using a total station?
Their accuracy cannot be beaten and while they are not as convenient as
handheld GPSes, their accuracy would be worth it for those concerned with
its compromise in using a GPS.
Cheers,
Heather

> ----------
> From:         Howard Beverly[SMTP:[log in to unmask]]
> Reply To:     HISTORICAL ARCHAEOLOGY
> Sent:         Thursday, January 04, 2001 11:22 AM
> To:   [log in to unmask]
> Subject:      Re: GPS
>
> GPS can be a very useful tool, but like all others tools it needs to be
> implemented correctly.  Three of the biggest problems in using GPS that I
> have encountered include not knowing the datum for the captured
> coordinates
> (are then in UTM, State Plane, Decimal Degree, NAD27, NAD83, WGS72
> HPGN/HARN, meters/feet ..etc); not applying the correction to the data
> (before selective availability was turned off); and not tracking enough
> satellites to give an accurate reading (mostly from hilly/heavy vegetation
> areas).
>
> The following link is to an article about the effect of turning off
> selective availability on GPS.  Also see GPSWorld, June 2000 for another
> article on the same subject.
> http://www.geospatial-online.com/0600/0600divis.html
>
> This article gives a good brief explanation on how selective availability
> affected GPS.
> http://www.geoplace.com/gw/2000/0008/0800gps.asp
>
> And this article discusses the difference between accuracy and precision
> with GPS.
> http://www.geoplace.com/gw/2000/1000/1000gps.asp
>
> Just some thoughts and suggestions for reading.
>
> howard
>
> Howard Beverly
> GIS Analyst
> Archaeologist
> System Administrator
> Wilbur Smith Associates
> Lexington, Kentucky
> [log in to unmask]
>