Electronic sextant

Claim 1

An improved double-reflecting sextant for accurately measuring an angle and for automatically providing angular measurement and time electrical output signals which are suitable for further electrical processing and automatic data reduction and comprising: a. a sextant including means for measuring an angle and including a horizon mirror-glass and an index mirror, whereby the sextant may be collimated by aligning an image of the horizon on the index mirror with a horizon sighting through the horizon mirror-glass, and then the altitude of a celestial body above the horizon may be measured by adjusting the angular position of the index mirror until an image of the celestial body on the index mirror is aligned with a horizon sighting through the horizon mirror-glass, and a digital encoder means for providing a digital electrical signal indicative of the magnitude of said measured angle; b. clock means for providing an accurate indication of the time at which the measurement is made and for producing an electrical output signal indicative of that time; and c. electronic means, including means actuated by the operator for completing an electrical circuit for a given period of time, for automatically providing synchronized output electrical signals from said measuring means and said clock means which are suitable for further electrical processing and automatic data reduction, said electronic means including first electronic means coupled to said encoder means for automatically providing an average of said angle measurement over the given period of time, and second electronic means coupled to said clock means for automatically providing an averaged time during which the measurement is made over the given period of time, whereby a single operator may take measurements with the sextant thereby eliminating the requirement for a second operator, and further eliminating synchronization and transcription errors between several operators.