Patent ID: 6259519
Filing Date: 2001-07-10
Classification: G01B,G01C

Abstract:
A method of determining the planar inclination of a surface comprising the steps of:modulating each of three lasers positioned within a sensor body with a different sine wave frequency based on stored values within a wave-table by superimposing onto the emitted light beam from each laser the respective sine wave frequency;emitting the light beam from each laser onto a surface to be analyzed;scattering the light beam emitted from each laser onto a respective position sensitive detector formed from a semiconductor chip that is positioned within the sensor body;demodulating each light beam by:producing electrical signals from each respective position sensitive detector corresponding to the position of the scattered light beam, andintegrating the electrical signals by values in the wave-table to obtain demodulated values; andcalculating the planar inclination of the surface based on the demodulated values.