ATLANTIC APPLIED RESEARCH CORPORATION HAS BEEN DEVELOPING A VERY HIGH ACCURACY LASER SURFACE SHAPE MEASUREMENT SYSTEM.

ATLANTIC APPLIED RESEARCH CORPORATION HAS BEEN DEVELOPING A VERY HIGH ACCURACY LASER SURFACE SHAPE MEASUREMENT SYSTEM. IT CURRENTLY HAS THE ABILITY TO SCAN A MEASUREMENT LASER BEAM IN ONE DIMENSION AND MEASURE THE POSITION OF THE SURFACE OF ALMOST ANY OBJECT IT STRIKES RELATIVE TO A REFERENCE PLANE. THIS NON CONTACT LINEAR DISPLACEMENT SENSOR PROJECT WOULD INVOLVE ADAPTING THE SCANNING MECHANISM SO THAT THE LASER BEAM WOULD BE DIRECTED ALTERNATELY AT THE PROBE AND AT THE MODEL'S SURFACE TO MEASURE THE DISTANCE BETWEEN THEM. COMPUTER PROGRAMS WOULD BE DEVELOPED TO ACQUIRE AND STORE THE POSITION DATA. THE SCANNING SYSTEM, INCLUDING THE LIGHT SOURCE AND RECEIVING PHTO DETECTOR WOULD BE LOCATED SEVERAL FEET FROM THE MODEL, OUTSIDE OF THE MACH 6 WIND TUNNEL. IT WILL OPERATE BY PASSING THE LIGHT THROUGH A WINDOW IN THE TUNNEL WALL. THUS THE HIGH INTERNAL TEMPERATURE IS NOT A PROBLEM. FOR PROBE AND MODEL SURFACES WHICH ARE DIFFUSE REFLECTING SURFACES, IT IS NOT NECESSARY TO ALIGN THE LASER BEAM NORMAL TO THE SURFACES BUT ONLY KNOW THE INCIDENCE ANGLE, SINCE THE SYSTEM USES A RANGE FINDING TECHNIQUE. A MINOR CORRECTION TO THE SPEED OF LIGHT DUE TO THE TEMPERATURE AND DENSITY OVER THE REGION BETWEEN THE PROBE AND THE MODEL MAY BE REQUIRED. THE SENSITIVITY OF THIS CORRECTION WILL BE INVESTIGATED. A DEPTH OF FIELD OF A 20 CENTIMETERS IS PRACTICAL. THE VERSATILITY OF THE SCANNING SYSTEM ALLOWS THE USE OF A SIMPLE SCANNER TO MEASURE MORE THAN ONE PROBE, IF DESIRED.