Regarding Satellite imagery making the intentional obfuscation of data a thing of the past: That is mostly true, *except* for cases where the owners of the Satellite, or their government "sponsors" decide or decree, that certain features considered too sensitive not be shown. Then, it is a simple matter - much simpler in fact than with paper maps - to digitally create "clouds" covering that feature (change the pixel's values to white), and release the image as if it were normal, when in fact, it hides a feature or features with the clouds. I know of one case from personal experience where this occurred, and I'm sure there have been and will be many others...
Of course now, with birds up from many governments and private companies, it's much more difficult to hide a given feature from everyone at all times. Just to stir the pot a bit! Mark Champney (remove "DONTSPAM" from address to send me email...) Colin Henderson wrote: > Just to add my own opinion to this particular thread. The argument that OS >"introduce" known errors into their data is incorrect. There was a time when it was >not possible to map secret military installations due to a threat to National >Security, in these cases "filler" data was added to the maps. However, with the >advent of satellite imagery being commercially available this is no longer a concern >and so does not happen any more. > > We can trace our data due to the way in which we collect and create it, by examining >third party data that is alleged to be copied from our own we are able to determine >whether or not it is ours. We also finger print some of our raster products and use >particular colour maps - all of which help us to determine whether or not our data >has been copied. > > I personally believe that it is essential to copyright data in order to protect it, >otherwise why would anybody bother to collect it in the first place. It costs money >to collect the data and generate output, it is not unreasonable for a company to >expect to be able to protect their investment and expenditure. > > If a company can't, within reason, protect its revenues then why should it bother to >collect the data. If this view was then taken by everyone we would end up in a >situation where would have no data or at the very least lots of very low quality data. > > Colin Henderson > GI Development > Ordnance Survey > > *************************************************************** > For more information on Ordnance Survey products and services, > visit our web site at http://www.ordnancesurvey.co.uk > *************************************************************** > > --------------------------------------------------------------------- > 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]
