Hemispherical sundial with installation indicia
Holographic sundial
Horizontal sundial adjustable for accurate reading at...
Laser guided celestial identification device
Latitude finder
Longitude location device
Method and apparatus for determining the position of stars
Method and apparatus for precise calibration of magnetic compass
Method and apparatus for sight reduction
Method of and apparatus for telling time at night
Modern sundial
Multipotent astrolabe
Plate sundial with installation indicia
Quasi-uniaxial solar trajectory tracking transit system
Reflected spot sundial
Remote light source responsive visual time indicator
Satellite locator
Satellite spacecraft targeting device and method
Self-orienting platform
Sextant having a microprocessor for calculating the position of