http://www.proaxis.com/~johnbell John Bell and Associates Newsletter Latest Articles http://www.proaxis.com/~johnbell/regular/regular_online8.htm Computer programs were always a problem, and the code never seemed to be checked by the people who actually understood the details. In some cases, they were not allowed to – only the geeks had access. http://www.proaxis.com/~johnbell/regular/regular_online7.htm George Deegan sent along this report of some work that he did with the DNR. He gave us permission to edit it slightly for the newsletter, but is essentially as he sent it to us. It is a wonderful example of the trade-off you get when you try for more data (tree VBARs) by estimating heights vs. carefully measuring a smaller number of tree VBARs that balance the Basal Area estimate. I remember seeing this same affect in cruises done in Michigan. http://www.proaxis.com/~johnbell/regular/regular_online6.htm I suppose all of us, particularly husbands, have a handful of “this is how stupid I once was” stories. Here is one from my professional life.... http://www.proaxis.com/~johnbell/compassman/compassman.htm Read the latest installment from Kim Iles second book. http://www.proaxis.com/~johnbell/iitt/questionsftf_online9.htm  There is an easy way to compute this with your own data. Get some of the diameters from one of your cruises. It could be a Big BAF cruise, a measure/count set of plots or any other method you use. The method does not matter at all, as long as they trees were selected with an angle gauge like a prism or Relascope. http://www.proaxis.com/~johnbell/guest/GPS_Canopy_Tests.pdf I’m a professional timber cruiser, based in the Redwood region of northern California. I wanted to determine the accuracy of GPS data capture at points under varying amounts of forest canopy, using a variety of available GPS receivers, software, accessories, and varying satellite conditions. This series of tests were conducted in an approximately 60-year old stand of mixed Redwood and hardwood trees in the central part of Humboldt County, California. http://www.proaxis.com/~johnbell/iitt/questionsftf_online8.htm Bill from the BLM posed an interesting question. He did a VP cruise, and the result was not good enough. He wanted a 5% sampling error. He already has too good an answer for VBAR, so what should he do? http://www.proaxis.com/~johnbell/regular/regular_online5.htm A friend of mine brought up a good point a few days ago.  He wondered if the "walkthrough method" was working well enough.  It’s a good edge effect correction, and an excellent way to properly balance the selection of trees correctly (something half plots and other techniques do not do well).