+Gungadoy Posted November 19, 2015 Share Posted November 19, 2015 (edited) I had an interesting find earlier this year while benchmarking along Tamiami Trail. It stretches from Miami to the west coast of S. Florida. If you wanted to see alligators in the wild, this would be the roadway to travel. Check out the pics at this adventure: Big Cypress Nat'l Preserve Has anyone seen one of these or have some info about their use? An Aerial Survey Target along the shoulder of the road. In fact there were several along the road in this stretch of roadway. You can see it on Google Earth on the SW side of the road near N 25 46 39.83902 W 080 50 40.33139 or by PID AJ7752; Only viewable on NGS site. Edited November 19, 2015 by Gungadoy Quote Link to comment
mloser Posted November 19, 2015 Share Posted November 19, 2015 I have never seen one made for the purpose like this. Quite often I have come across painted crosses or painted Ts. A couple of times I found white plastic across a tri-station in a large X shape, once in great shape, a few times partly disintegrated. Quote Link to comment
+DukeOfURL01 Posted December 13, 2015 Share Posted December 13, 2015 (edited) I believe those, and big crosses that you sometimes see at or near benchmarks, are for Geo-rectifying aerial photos. Edited December 13, 2015 by DukeOfURL01 Quote Link to comment
Z15 Posted December 14, 2015 Share Posted December 14, 2015 (edited) On all the aerial photos we placed for mapping at the DOT in my 30 yrs (were a lot), the Photogrammetry Engineer always furnished us a topo map with the flight path and where he wanted us to place the targets as well as what size to use, the paint (white or yellow) for pavement and white vinyl panels for terrain (woods etc) locations. We always put down black plastic so they could find the "X" in the photos. Typically we always used 8 inch x 8 ft "X" or a "V". Higher flights (to cover larger area) required different sizes like a 16x16 ft"X" but those were rare and usually for preliminary route location for wider coverage. We had to provide XYZ coordinates for all the points we marked and he often chose what were called wing shots (outer edge of flight path) for elevations only. It all depend on what they were going to use the photo's for, sometimes we never ran control because he had us place the targets at certain distances apart to have a scale for preliminary route location studies. Note - The yellow painted "X" almost always cause some stir among the public with all kinds of black opps theories for them and many never believed they were for aerial mapping for highway improvements. Once we were painting them along US-41 when a local county cop stopped and aske; are you going to widen the road? My partner said, No, were going to make it longer! The cop gave him a nasty look and took off like a bullet. One time the maint. dept had to send a crew out to obliterate some after the flight because some people were afraid to drive over them and were calling police etc. Weird! That was along US2. Edited December 14, 2015 by Z15 Quote Link to comment
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