This IS a common practice - in mail order they SALT with fictional addresses (which they monitor via PO box) and in GIS the number is FUDGED with either additional detail (4decimal become 6decimal), rounding within practical limits (see earlier post), universal shifting in any one direction (think 360 degrees of encryption <plus added detail above>) within practical limits (ie: GDT old school) or unique projection system (now who did that?) - in any case, it ultimately becomes the positional accuracy between other items - if the resolution is high enough in the created data and designed to work with common 1:100,000 or 250,000 scaled data then you have a couple of decimal to play with and not get into trouble.
There are a lot of different ways to "fudge" the data without rendering it worthless - just stay within the specification of implied use and you should fine. No one ever said (or used) 1:100,000 scale maps for city utility maps. Hope that helps and supports some of the suggestions on this thread Regards Ralph -----Original Message----- From: Christof Kaiser [mailto:[EMAIL PROTECTED]] Sent: Tuesday, April 30, 2002 9:18 AM To: 'ALICIA COX'; [EMAIL PROTECTED] Subject: Re: MI-L Protecting GIS data (cross-posted), reply > Von: ALICIA COX [SMTP:[EMAIL PROTECTED]] > Ok. If I am understanding this conversation... > If someone successfully copyrights a set of data... > Then we are buying fictional data? A set of data that we know there is > an intentional error in it??? > If the table is purposefully wrong why do we use it, especially if they > wont even tell you were the error is, Since that spot they have the > error might be the focus area of the map you are attempting to make. As long as the intentional error in smaller than the agreed accuracy, there is no problem. Just see the intentional error as part of the noise that is in every data. Lets say the accuracy is one meter. However, the data technically also contains cm. So I could think of a 'tell tale' which makes the last cm digit in some cases to a 7. I wouldnt call that data corrupted. Regards Christof --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --- --- --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
