User:Mav/Data Acquisition in GIS notes by maveric149/2002-04-05 Lecture

Data Acquisition in GIS notes by maveric149 2002-04-05 Lecture

Digitizing of data

turning something into coputer readable format - literally turing it into 1s and 0s. In other words representing something mathematically that was not initially mathematical.

Digitizer =

is a tablet with a grid of wires under a plastic covering. To mark positions you use a "curser" (mouse-like device). The resolution of the table is based on the number of wires that are in the grid. Wen you push the button on the cursor it sends out a magnetic signal that is picked up by the grid - marking the position.

Scanning

inside the scanner is an array of photodectors. Alalog would be a satellite moving over the earth and scanning the surface. Its angle in constantly changing. It has a lightsource, surface, and detector array. Physical resolution is the number of detectors in every inch.

Lecture: Digitizing theory, hardware museum pieces

On Scanning:

http://www.scantips.com/ Best beginner's site I've run across so far (pv).

Scanning Manufacturers:

HP, Umax, Microtek, Epson

Scanning Demo

ArcView Image Analysis Extension Demo: Georeferencing an Image

WebSites of the Week on Digitizing:

http://www.ssg-surfer.com/?source=goto
This is the main site for this company

http://www.ssg-surfer.com/html/didger_details.html
This is where the digitizing software info is. interesting info on current product.

http://www.innovativegis.com/education/primer/sources.html
This has some good information on Digitizing.

http://www.geography.ccsu.edu/harmonj/g378/html/prod/sld001.htm
Here is a Power Point Presentation useful information for lecture.

http://www.giscafe.com/Download/Digitizing_Tools/
This is a site that has FREE digitizing tools. I dont know anything about them. I havent had time to check out the site yet.

http://web.mit.edu/gis/www/arcviewdigitizing/
This is a great site ! It has wonderful screen shots and lays out the exercises very clearly.