UNMANNED SEISMOMETER LEVELS SELF, CORRECTS DRIFT ERRORS

An advanced design, four-component, three-axis, feedback-controlled seismiograph is described which can be used for detecting and recording earthquake waves where the seismograph must be put in a remote location and will be manned. Electronic circuitry is included for levelling, as well as monitoring the feedback signal required for servocentering. A matched set of 3 long-period seismometers sense motion in two orthogonal horizontal directions and one in the vertical. A fourth seismometer, which is a short period device, is also aligned in the vertical plane. Automatic circuitry and mechanisms are provided. The package which is less than one cubic foot and weighs approximately 24 pounds contains three subsystems, namely, an electronic pick-off and feedback, and a levelling and vertical centering system. Aspects such as installation on irregular surfaces, detection of earth motion, compensation for residual drift, centering of each horizontal component, the feedback control of the short-period vertical seismometer, and the breadboard system are briefly outlined.

• Corporate Authors:

  National Aeronautics and Space Administration

  600 Independence Avenue, SW
  Washington, DC  United States  20546
• Publication Date: 1964-5

Media Info

• Features: Figures;
• Pagination: 2 p.

Subject/Index Terms

• TRT Terms: Automation; Building; Drift; Earthquakes; Electric circuits; Electronic equipment; Errors; Facilities; Feedback control; Installation; Leveling; Monitoring; Remote control; Remote sensing; Seismometers; Servomechanisms; Values in measurement
• Uncontrolled Terms: Correction (Mathematics); Residual value
• Old TRIS Terms: Circuits; Electronic devices
• Subject Areas: Construction; Geotechnology; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 00081529
• Record Type: Publication
• Report/Paper Numbers: Brief 63-10551
• Files: TRIS
• Created Date: Mar 6 1975 12:00AM