"dpb" wrote in message
...
wrote:
...

Just out of curiosity, why do you need accuracy in plot layout to a
tenth of an acre on an 80-100 acre plot? That's .1% accuracy, which
seems extreme for common agri plot sizing.

That's consistent w/ FSA measurements for compliance; of course, they have
their USDA-issued devices that I've no idea what cost. If there's an
overage, one can be penalized so it is advantageous to be accurate. It
didn't use to be so much an issue before the GPS-based surveys and
4-wheelers; now they monitor much more closely since have the facility to
do so as compared when they had to use the old measuring wheel or chain.

Realistically, if within about an acre would be adequate; what I was
thinking is that if, indeed, the waypoints are 10-ft off in worst case
that could be nearly 4A in the total aggregate if each side happened to
stack up wrong. And, of course, there are other fields that are full mile
in length and the 1 rod equates to 2A over the length so a few feet can
begin to add up to measurable difference fairly quickly.

--
If it's essentially a one-time use, consider renting a Trimble back-pack
unit for a day or so. In a recent trial here, we located rare plants --
seedlings -- that were going into the ground, for which we needed continued
historical data (e.g., seed source, growing medium, transplant success, etc.
We GPS'd 700 plants, most of which were at most 2 feet apart and came up
with a plot using Arcmap that shows each individual plant in a small area
about 30' x 30'. Now we can go back to individual plants and measure their
growth, vitality, etc. (A previous planting tried using plant tags and
small flags to identify each plant, but neighborhood youth discovered the
site, picked up the flags, and moved the plant tags around, which meant the
group lost all of its records for individual plants.)