Martin Brenner's, Pilot Balloon Resources
Warren-Knight Electronic Observation Theodolite 20-9103
This model 20-91003 was acquired in 2007 from Canada. This is a high accuracy digital pilot balloon theodolite that was designed to allow other uses such as alignment of ILS gear as well as other tasks. It is over an order of magnitude more accurate than would be necessary solely for pilot balloon work.
The model 20-9103 has the same optical and mechanical tracking system as a manual theodolite (a user familiar with previous models will have no trouble operating it). This model improves on previous generations by adding an LCD display and an RS232 serial data interface. The angular presentation is user selectable to show degrees minutes and seconds with a resolution of 10 arc seconds, or decimal equivalent with a resolution of .001 degrees. On this model reading is digital LCD and RS232 only.
The instrument has been designed to accept motor drives and worm driven potentiometer and encoders, allowing the model of electronic theodolites to work with legacy systems designed for use with the older theodolites.
The RS232 output allows single user operation with absolute theodolite positions being transmitted.