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June 1, 2005

What's an orthophotomap, and how do I catalog it?

A cataloger asks this question on AUTOCAT:

I'm cataloging a map from our state Dept. of Transportation that has been released in 2 versions. Both are exactly the same map, except that one has been superimposed on top of an aerial photograph. Both have exactly the same title, size, scale etc. The only difference is that one says "Photograph not to scale" on the bottom and the other doesn't. (If the map is to scale and the photograph matches the map, then why isn't the photograph to scale too?)

Is there a standard terminology among map catalogers for a map superimposed on top of a photograph, and how in the world do I make the distinction between these 2 maps clear in the OPAC?

Here's the response from map cataloging guru Paige Andrew:

Questions? Contact Stacie.

Posted by trail001 at 10:43 AM

Trivia: What's up with 007 coding for CD speed?

A recent discussion on the AUTOCAT list addressed the reason why the speed of an audio compact disc is 1.4 meters per second (007/03 f). Just in case you're curious, here's a good explanation of why this is the case:

"CDs and DVDs address this by using what is called Constant Linear Velocity (CLV) The surface moves past the read head at a constant rate. This means as the pickup head moves from the center toward the edge of the disc, the disc does not have to turn as fast since there is more ground to cover. It is akin to the old "whirly go round" at the park. The kid on the outside had to run fast, but the kid in the center barely had to move. The rate chosen was 1.4 meters per second. As the disc plays, there is more "landscape" to record on so the disc doesn't need to move as fast."

Posted by trail001 at 10:30 AM