LASER-OPTICAL SYSTEM FOR PRECISE DISTANCE MEASUREMENTS

THE MEASUREMENT OF GEODETIC DISTANCES WITH A TUNGSTEN OR A MERCURY VAPOR LAMP ACHIEVES A FAIRLY HIGH DEGREE OF ACCURACY, BUT IS LIMITED IN RANGE AND OBSERVATIONS HAVE TO BE MADE AT NIGHT. AN INSTRUMENT WITH A LASAR LIGHT SOURCE, TO INCREASE ACCURACY AND TO MEASURE LONGER DISTANCES IN BRIGHT SUNLIGHT, IS DESCRIBED. THE TRANSMITTER COMPONENTS CONSIST OF A 2 MILLIWATT GAS LASAR, A KDP CELL, AND A BEAM EXPANDER. AS THE 2 MILLIMETER LASAR BEAM PASSES THROUGH THE BEAM EXPANDER, THE BEAM IS EXPANDED TO 20 MILLIMETERS. THE BEAM EXPANDER IS ADJUSTABLE, AND THE BEAM CAN BE AOLLIMATED FROM ABOUT 1.5 METERS TO ABOUT 30 METERS AT TEN MILES. TO ELIMINATE AS MUCH ERROR AS POSSIBLE, A CRYSTAL OVEN WAS DEVELOPED, WITH A MERCURY THERMISTOR TO CONTROL THE OVEN TEMPERATURE. IN A PRECISION TEST THE INSTRUMENT OPERATED VERY SMOOTHLY. THE MEAN OF FOUR MEASUREMENTS WAS 3 MILLIMETERS LONGER THAN THE MEAN TAPED DISTANCE. THE LASAR LIGHT IS NOT DANGEROUS EXCEPT TO THE EYES AND THIS DANGER CAN BE AVOIDED BY OBSERVING A FEW SAFETY PRECAUTIONS.

  • Supplemental Notes:
    • Vol 61, No 402, PP 250-253, 4 FIG
  • Authors:
    • Lesley, G B
  • Publication Date: 1969-7

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  • Accession Number: 00202788
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 20 1994 12:00AM