GPS Tips
GPS systems are wonderful inventions. There is probably no better application of
this technology than the collection of samples for geochemical surveys. The
relatively old Garmin 12XL (Garmin has discontinued the 12XL, the Garmin Etek
Legend is a good replacement that does more and costs less.) that I have seems
almost designed specifically for sample collection. After the government stopped
degrading the accuracy of these tools there is no better way to do sample
collection. A completely inexperienced person, with just a minimum of training,
using a properly programmed GPS system can flawlessly collect even a
complicated detailed survey. The tests I have run on the accuracy of a programed
collection point and the marked sample point is between 1 and 5 meters or 3 to 15
feet.
this technology than the collection of samples for geochemical surveys. The
relatively old Garmin 12XL (Garmin has discontinued the 12XL, the Garmin Etek
Legend is a good replacement that does more and costs less.) that I have seems
almost designed specifically for sample collection. After the government stopped
degrading the accuracy of these tools there is no better way to do sample
collection. A completely inexperienced person, with just a minimum of training,
using a properly programmed GPS system can flawlessly collect even a
complicated detailed survey. The tests I have run on the accuracy of a programed
collection point and the marked sample point is between 1 and 5 meters or 3 to 15
feet.
Computers and GPS
Most USGS map programs will
upload and download from a
variety of GPS systems. The
Maptech program, which I use,
provides all of the USGS maps
for an entire state for $100 per
state. It can be used to digitize
collection points that can be
downloaded to your GPS. In the
field the collector simply walks
or drives to the marked point,
collects a sample in a numbered
bag and "marks" the point of
collection with the same number
as the sample bag.
upload and download from a
variety of GPS systems. The
Maptech program, which I use,
provides all of the USGS maps
for an entire state for $100 per
state. It can be used to digitize
collection points that can be
downloaded to your GPS. In the
field the collector simply walks
or drives to the marked point,
collects a sample in a numbered
bag and "marks" the point of
collection with the same number
as the sample bag.
Maptech Terrain Navigator - Locate your area of interest.
Using the
"Marker
Tool" select
each point on
the map you
would like to
collect a
sample. In
this example
samples are
being
collected
along the
available
roads using
1/10th mile
spacing.
"Marker
Tool" select
each point on
the map you
would like to
collect a
sample. In
this example
samples are
being
collected
along the
available
roads using
1/10th mile
spacing.
GPS downloads
After all points have been marked,
select the "GPS" menu and then
"Send Markers", the program will
download your collection points to
your GPS.
select the "GPS" menu and then
"Send Markers", the program will
download your collection points to
your GPS.
GPS in the Field
In the field, each collection point will appear on the map page of your GPS. You will simply drive or
walk until your "current position" mark overlaps your selected collection point and take the sample. It
is always good to "mark" the collection point with your GPS inputing the bag number used for that
sample.
walk until your "current position" mark overlaps your selected collection point and take the sample. It
is always good to "mark" the collection point with your GPS inputing the bag number used for that
sample.
GrayStone Exploration Labs, Inc.
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