REGIONAL CONTROL SUPPLIED BY PHOTOGRAMMETRY

THE U. S. COAST AND GEODETIC SURVEY HAS DEVELOPED, TESTED, AND IS USING A PRECISE SYSTEM OF ANALYTIC AEROTRIANGULATION WHICH MAY BE APPLICABLE TO SURVEYS FOR HIGHWAYS, SUBURBAN (AND POSSIBLY URBAN) UTILITIES AND NATURAL RESOURCES. WHERE SECOND-ORDER GEODETIC CONTROL HAS A SPACING OF 3--5 MILES, THE POSITIONS AND ELEVATIONS OF A VIRTUALLY UNLIMITED NUMBER OF PREMARKED GROUND POINTS WITHIN A CONTROL FIGURE CAN BE DETERMINED WITH A RMS ERROR OF 0.15 FT HORIZONTALLY AND 0.25 FT VERTICALLY FOR A TOTAL COST OF ABOUT $5000 FOR 25 SQ MILES. A BLOCK OF 25 PHOTOGRAPHS IS A PRACTICAL UNIT TAKEN FROM AN ALTITUDE OF 5000--7500 FT WITH A GLASS-PLATE CAMERA AND AN OVERLAP OF 60% IN BOTH DIRECTIONS. CORRECTIONS ARE MADE FOR COMPARATOR ERRORS, FILM DEFORMATION (IF FILM IS USED), LENS DISTORTION, AND ATMOSPHERIC REFRACTION, AND A RECTANGULAR GEOCENTRIC COORDINATE SYSTEM IS APPLIED FOR EARTH CURVATURE EFFECTS. THE PREMARKED GROUND POINTS BECOME RECOVERABLE SUPPLEMENTAL CONTROL. THEREAFTER LOWER-ALTITUDE- FILM CAN BE USED FOR MAPPING IN THREE DIMENSIONS WITH CONVENTIONAL PLOTTING INSTRUMENTS WITHOUT FURTHER FIELD SURVEYS. /AUTHOR/

  • Supplemental Notes:
    • Vol 27, No SU 1, PROC PAPER 8136, PP 13-25
  • Corporate Authors:

    American Society of Civil Engineers

    345 East 47th Street
    New York, NY  United States  10017-2398
  • Authors:
    • Tewinkel, G C
  • Publication Date: 1971-5

Media Info

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Filing Info

  • Accession Number: 00202899
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 2 1971 12:00AM