Post by Wyldcomfort on Jul 28, 2007 6:41:54 GMT -5
Here is a note from Dean regarding GPSing. I also wanted to thank Jody for his hard work in mapping Horsefal. We all need to let him know how much we appreciate his efforts on our behalf. He has spent months working on this.... Have a wonderful day and please do what you can to assist in this matter.... Oh - still no word on SB101 signing.... Thanks, Lindy
The following two examples show GPS data collected by ATV'ers in an attempt
to capture some of the ATV trails on the Oregon Dunes. This is a very
small representation of the mass number of trails actually out there. As
you can see, there are places where the GPS data is very good and other
places where GPS data was collected only a few moments later that is a long
way from the actual location. Without a significant amount of manual
editing, plus knowledge of those trails, it is nearly impossible to produce
an accurate product. The GPS data collection receivers we have at the
Forest Service provide more consistent results, but still experience
similar problems which cannot be predicted.
If you still plan on gathering GPS data, rather than attempting to collect
mass amounts of data regarding the location of each trail, I like how Jody
chose to only GPS the perimeter of the riding area for Horsfall. Even with
collecting only the perimeter, it still took 7 hours of steady riding time.
PDF not available.
(See attached file: winchester.pdf)(See attached file:
horsfall_utm_photo_trails.pdf)
Feel free to share these examples with the other folks who have been
thinking of possibly GPS'ing more ATV trails. Also, if the GPS receivers
are WAAS enabled, there has been a change in satellites that provide the
WAAS signal. Their GPS receivers may be looking for unavailable satellites
and may no longer benefit from the WAAS location corrections. Garmin and
Trimble have downloadable firmware to correct this.
Dean Devlin
GIS/Data Services Specialist
U.S. Forest Service
R-6 DRM Customer Services Area 2
e-mail: ddevlin@fs.fed.us Phone: (541) 271-6052
Duty Station: Oregon Dunes NRA, Reedsport OR
The following two examples show GPS data collected by ATV'ers in an attempt
to capture some of the ATV trails on the Oregon Dunes. This is a very
small representation of the mass number of trails actually out there. As
you can see, there are places where the GPS data is very good and other
places where GPS data was collected only a few moments later that is a long
way from the actual location. Without a significant amount of manual
editing, plus knowledge of those trails, it is nearly impossible to produce
an accurate product. The GPS data collection receivers we have at the
Forest Service provide more consistent results, but still experience
similar problems which cannot be predicted.
If you still plan on gathering GPS data, rather than attempting to collect
mass amounts of data regarding the location of each trail, I like how Jody
chose to only GPS the perimeter of the riding area for Horsfall. Even with
collecting only the perimeter, it still took 7 hours of steady riding time.
PDF not available.
(See attached file: winchester.pdf)(See attached file:
horsfall_utm_photo_trails.pdf)
Feel free to share these examples with the other folks who have been
thinking of possibly GPS'ing more ATV trails. Also, if the GPS receivers
are WAAS enabled, there has been a change in satellites that provide the
WAAS signal. Their GPS receivers may be looking for unavailable satellites
and may no longer benefit from the WAAS location corrections. Garmin and
Trimble have downloadable firmware to correct this.
Dean Devlin
GIS/Data Services Specialist
U.S. Forest Service
R-6 DRM Customer Services Area 2
e-mail: ddevlin@fs.fed.us Phone: (541) 271-6052
Duty Station: Oregon Dunes NRA, Reedsport OR