Patent ID: 7251899

Claim:
A direct reading prism pole for automatically taking height measurements and providing corresponding height reference data, comprising: a) a tubular housing having an open top, a flange positioned at the open top, and a conical bottom portion for wedging the tubular housing into ground soil; b) a height-adjustable rod partially inserted into the tubular housing and having an outer diameter just less than an inner diameter of the tubular housing to create a friction fit therebetween for positioning the height-adjustable rod with respect to the tubular housing; c) an encoded strip of optically-perceptible markings positioned longitudinally on the height-adjustable rod; d) an electronic control unit having an optical reader, the electronic control unit being mounted on the flange at a reading point to obtain height measurements from the encoded strip, and the electronic control unit processing the height measurements into height reference data; e) an electronic display in electrical communication with the electronic control unit for receiving the height reference data and displaying the height reference data on a screen; f) an audio device in electrical communication with the electronic control unit for emitting an alarm in response to receipt of a signal from the electronic control unit indicating movement of the height-adjustable rod with respect to the tubular housing; and g) an output device in electrical communication with the electronic control unit for sending the height reference data to a data collection device.