SURVEYORS RAISE SIGHTS WITH INFRA-RED

THE AUTHOR REPORTS ON THE USE OF AN INFRA-RED TACHOMETER BY A SURVEYING ORGANIZATION AT CHEDDAR. THIS EQUIPMENT (A WILD D13 DISTOMAT) COSTING ABOUT found5000 IS SAID TO BE REDUCING THE TIME OF SURVEYING OPERATIONS BY ABOUT 60 PER CENT, BUT THIS ADVANTAGE IS BEING PARTLY OFFSET BY ITS USE BEING RESTRICTED TO SENIOR STAFF (BECAUSE OF ITS HIGH VALUE RATHER THAN GREATER DIFFICULTY IN USE). THE EQUIPMENT CONSISTS OF COMPUTER UNIT MOUNTED BENEATH THE THEODOLITE ON THE TRIBRACH. THE VERTICAL ANGLE IS MEASURED IN THE NORMAL WAY WHILST THE INSTRUMENT AUTOMATICALLY MEASURES THE INCLINED DISTANCE, WHICH IS DISPLAYED ON A PANEL. THIS OPERATION TAKES ABOUT 10 SECONDS AND AN AVERAGE IS GIVEN IN THE EVENT OF SWAY. SWITCHES ARE USED TO CAUSE THE INSTRUMENT TO COMPUTE AND DISPLAY VERTICAL AND HORIZONTAL DISTANCES. IT HAS A RANGE OF 900M AND ACCURACY OF +OR-5MM. THE INSTRUMENT HAS PARTICULAR VALUE FOR OPERATIONS WHERE MANY OBSERVATIONS ARE MADE FROM A LIMITED NUMBER OF SET-UPS, SUCH AS THOSE EMPLOYING POLAR CO-ORDINATES. SETTING OUT OPERATIONS AND THEN DIRECT PLOTTING OF TOPOGRAPHY ARE SPECIFICALLY MENTIONED.

  • Availability:
  • Corporate Authors:

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 
  • Authors:
    • Atkinson, I
  • Publication Date: 1974-10-24

Media Info

  • Features: Photos;
  • Pagination: p. 40
  • Serial:
    • CONTRACT JOURNAL
    • Volume: 261
    • Issue Number: 4964
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00083847
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: May 1 1975 12:00AM