Above is a clip of the overall map better 2008 map I found online.I was going to insert it below the smaller clip below but I am still trying to get used to this blog format and how to move and edit image inserts.
We need to know. We need a central cooperative system to manage true positions or a way to qualify the positions as to accuracy.
Map Lat/Lon as shown by address - how correct is it on Google Earth or other maps that can look up and show a picture of the house or lot?
As a surveyor I have also found that when I find the true lat/lon using WGS84 datum, I many times get a different position that the exact same object or point I see on the photo overlay. For example, let me look up an address such as 9111 Freedom Ave, Sapulpa, OK 74066 with Google Earth on 20090913:
I have been there, I surveyed that area, and I know that other map locations true lat/lon locations are about 74 feet east and about 14 feet north of the photo position of any point in that area. This particular address/photo location is good and I know it matches up with reality even though the location on the true grid of the photo may be off as much as 80 feet East-North-East here.
How does a person contact the outfit that positions the photo on their grid for their maps. Let me know when you find out because there is little to know contact link to seek answers or a better map or system to quality or correct or certify any of this information except for maybe a few of us Land Surveyors who care enough to try or even understand that the errors exist.
By the way - that aerial view is OLD and that area has changed a lot. There is good 2008 and soon, 2009 county maps available on line downloadable - very big and time consuming to download but available for us to download with patience and high speed connections. Too bad they cannot connect them online to view online like existing OLD aerial overlays. We have come a long way but we can sure integrate what we have better for improvements.
No comments:
Post a Comment