Prof. Y. Lupardi

And a Dutch one .

quote:Originally posted by Jiheffe:[...]posted a topic on exporting the maps to OziExplorer using screen captures and some stitching in Paint Shop Pro. Quite cluttery to do, but the results are interesting! Once in OziExplorer, you can play around with routes, tracks, etc...[...] Last weekend I was at a Belgium GC-event. There I found out that there is also (just as in Holland we seem to have a KabouterBond) a group of Flamish gnomes doing their good works out of sight. I have seen a CD with all 1:50.000 maps ready for use with Ozi Explorer. These disks pop up in caches it seems.

quote:Originally posted by newly_weds:It seems you are able to download a full database of the benchmark points .. is this a working version? We only have about 5600 surveyed points. And the list you can get to download at: http://rdnap.kadaster.nl/rd/help.html is only accurate at 10 meters. Used for finding the markers. Then there is a list on paper you can order for 40 euro. That one has them on the meter and a description of the place. But if you want to get the real accurate positions you have to pay a lot. Or have a good story about scientific need to get a few for free.

In this low-lying muddy tiny country in Europe we have also benchmarks. The official and known ones are part of the RD-grid, a local network of markers. Within this set there are special GPS-Kernnet points. The total number (inclusive churchtowers, watertowers etc.) is about 5500. See more about them here: http://rdnap.kadaster.nl/rd/index.html and push button 'gast'. And of course there are many free or wild markers nailed in by all kind of organisations for al kind of purposes. The offical markers are not very spectaculair here: bald nails in concrete. For our hunting site (we are working on it): http://www.geocaching.nl/benchmark/index.htm A site is being made so finders can place stories and photographs there. About my own adventures there are some illustrated stories (in Dutch!): http://www.xs4all.nl/~atarist/geo/hunt1/benchmarkhunting.htm A short text about benchmark hunting can also be found here: http://www.xs4all.nl/~atarist/geo/benchmark.htm Prof. Y. Lupardi

quote:Originally posted by rusty0101:[...]My question is how is a surveyors gps used? [...]In a couple of other threads I read that surveyors start from a known benchmark with their GPS and work off of those readings. My suspicion is [...] -Rusty You do not have to be a surveyor or have super-expensive machines if you have time on your hands. I have experimented with a GPS12 and managed to get the position of a corner of my roof within 20 cm. I also tested benchmarks of known position to verify this. More you can read on my webpage: http://www.xs4all.nl/~atarist/geo/gps_accuracy.htm

quote:Originally posted by survey tech:Pacing can be very useful. With a little practice you can regularly get within 1-2 feet on a level surface over a distance of 100 feet or more. [...]. With a rope between your ankles you can walk in very precise steps (do not fall over, takes some learning:-). Most people are big enough to make steps of 1 meter, so with a bit of calibration of the ropelength, pacing metrically precisely is easy.

quote:Originally posted by ca_surveyor: The RTK (Real Time Kinematic) system costs about $20 to $30 k depending upon which bells and whistles you want.. Check out Trimbles web site for more exotic stuff. . I am very lucky to live in a town in the Netherlands where there is a firm selling second hand surveyer (GPS) stuff. See: http://www.lnrglobalcom.nl/site/occasions where they have a few Leica SR9500/AT302 GPS multistations for only 7.5 K Euro ( is about the same in $$). So let mentioned prices of 20/30 K$ not stop your search. Look around: somewhere in the USA someone will be selling second hand also! Prof. Y. Lupardi