OBSTRUCTION DETECTION PROGRAM

A LASER-SCANNING SYSTEM WAS DEVELOPED FOR DETECTING SMALL OBJECTS THAT MAY BE ON A GUIDEWAY SURFACE. THE SYSTEM USES A COLLECTION OF TRANSMITTERS AND RECEIVERS APPROPRIATELY SPACED ALONG THE GUIDEWAY TO SCAN ACROSS THE GUIDEWAY AGAINST A CONTINUOUS RETRO-REFLECTIVE FENCE. THE TRANSMITTERS EMIT A NARROW BEAM OF LIGHT FROM A GALLIUM-ARSENIDE LASER. A PHOTO-DIODE RECEIVER LOCATED AT THE CENTER OF THE TRANSMITTER MONITORS THE REFLECTIONS FROM THE RETRO-REFLECTORS DURING THE SCANNING OPERATION. AN OBJECT WHICH GETS IN THE WAY OF THE BEAM WILL CAUSE THE RECEIVER TO SEE A BLANK SPOT. THIS VARIATION IS REPORTED TO A CENTRAL CONTROL STATION WHICH COMMUNICATES PROPER WARNINGS TO ANY VEHICLE IN THE VICINITY OF THE OBJECT SO THAT CRASH AVOIDANCE ACTIONS MAY BE TAKEN. THIS WAS A FEASIBILITY PROGRAM. AN ENGINEERING MODEL WAS CONSTRUCTED,REFLECTIVITY LOSSES CAUSED BY CONTAMINATION BUILD-UP WERE DETERMINED, AND ATMOSPHERIC TRANSMISSION CHARACTERISTICS WERE MEASURED. THE SYSTEM APPEARED TO BE ECONOMICALLY AND TECHNICALLY FEASIBLE. /AUTHOR/

• Corporate Authors:

  Department of Transportation

  /Office of High Speed Transportation
  ,   United States 
• Publication Date: 1969-3-15

Subject/Index Terms

• TRT Terms: Crashes; Detectors; Feasibility analysis; Lasers; Obstructions (Navigation); Signal to noise ratio; Vehicle detectors; Warning systems
• Old TRIS Terms: Obstruction
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225727
• Record Type: Publication
• Source Agency: Traffic Systems Reviews & Abstracts
• Files: TRIS, USDOT
• Created Date: Jun 15 1970 12:00AM