Hey I agree with you Don....for most of my career it was the same, a silva compass, clinometer, 75 ft logging tape and a 10 factor prism. As for photography, what we had back in the 70's was great, but in the mid 80's they changed to the NHAP or whatever the acronym was for the high altitude photos...they were worthless. For several years the contrast and pixilation was so poor and the error in rectification was in excess of 10%. Once we started getting digitized products, we used some of the Blue Marble programs to try and correct some of the faults, but that was a pain. They got a little better over the years, but still were nowhere as good as the hard copy prints flown back in the 60's and 70's. In the coastal GA there wasn't ten foot of relief, so topo's and DEM's were useless. Finally in the late 90's we started using CIR, color infared, which were a vast improvement as we did a lot of stand typing. We didn't have access to the better photography that was made for some federal parks except on the coastal islands. So much of our timber land was either conifer or evergreen broadleaf, the CIR made the typing much clearer.
With the GPS units, they were more of a novelty at first, though we did use them to measure stands, waypoint bug spots, map skid trails and the like, but had to bring them back to the office to dial up the DC files from the local military base. After they removed the selective offsets a few years back it made them a little more practical, but we never used anything close to survey grade instruments. As for the waypoints taken at Congaree, I did average them for 50-100 points, but did not see the need for any other post processing as all I was recording was averaged points and the skies were clear and the canopy and other reflective areas pretty nil. Should be plenty adaquate for what it is to be used for. On Mar 5, 3:45 pm, DON BERTOLETTE <[email protected]> wrote: > Larry- > As a field forester for much of my life, my most valuable and accompanying > tools in the woods were a Silva Ranger compass, a Suunto clinometer, a rag > tape, a topo map, and a stereo pair of aerial photographs. > Like Paul, those tools were of inestimable value in getting around in the > woods. Still are. It's only now in my retirement that I've considered > getting a GPS. > One tool that evolved from this original set, came through the technological > advantage of being a GIS technician. When I was tasked with assembling a > vegetation map for Grand Canyon (for input into a fire area growth model), > the morphing of a topo map onto an aerial photograph was the very synergistic > result. Taking digital versions of each allowed the overlaying of separated > layers of a topo, onto a digital orthophoto quad (a digitized aerial > photograph). The result was the best of both worlds. I was often heard > saying in those times, that you could almost 'see the topo contours on the > ground' when walking in the field with these 'ortho-photo' maps. > One of the benefits of these maps was when you made changes in vegetation > type delineations in the field, back in the office, you didn't have to > rescale...you brought up the same imagery in a GIS, moved the field changes > into the office copy and you were done. > But I do like GPSs for similar tasks...but much more care needs to be taken > to be able to transfer GPS data into a GIS environment...instead of just > grabbing a coordinate pair, you need to 'average' the point, and post process > to get the accuracy required for topo standards. Handheld GPS accuracy often > times 'hovers' around the thickness of a line on a topo map. > -Don > > > > > > > From: [email protected] > > To: [email protected] > > Subject: [ENTS] Re: GPS > > Date: Thu, 5 Mar 2009 09:12:20 -0600 > > > I've never spent the money on that stuff yet. There is so much free > > publicly accessible aerial imagery and topographic maps for the entire > > country that I never thought that it was worth it to me to have the software > > with the little extra functionality - the 48 contiguous states have nearly > > complete coverage with free downloadable data from government sources such > > as the USDA, USGS, AmericaView, and most state's GIS departments. I print > > out aerial photos and topo maps for free for where ever I go and sometimes > > enter waypoints on my GPS since I rarely want to follow an exact preplanned > > route. I'm not sure what else you gain by spending the money on the > > software. Maybe I'm a little old fashioned. I use the GPS as a > > navigational aid only when needed and to mark trees, but try to rely on > > compass and map skills to save the gps batteries and to not become to > > reliant on it. > > > Paul > > > ----- Original Message ----- > > From: "Larry" <[email protected]> > > To: "ENTSTrees" <[email protected]> > > Sent: Thursday, March 05, 2009 7:36 AM > > Subject: [ENTS] Re: GPS > > > > Will, Paul, et al, Should I get the 2008 mapsource software with this > > > gps, I noticed they have several regions? Larry > > _________________________________________________________________ > Windows Live™ Contacts: Organize your contact > list.http://windowslive.com/connect/post/marcusatmicrosoft.spaces.live.com...- > Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en -~----------~----~----~----~------~----~------~--~---
