Pacific Northwest Geodetic Array
Central Washington University

Redmond-type Monuments

Redmond-type monuments are low cost bedrock monuments modified from the RBUT UNAVCO design. The monument consists of a 3 meter length of 2.5 cm diameter INVAR rod with a center punch on the end as the mark. The INVAR rod is set vertically within vertical 2 meter-deep drill hole, leaving about 1 meter of rod above above the surface. Non-shrink grout anchors the INVAR rod within the lower 1.5 meters of the drill hole. A concrete collar with epoxy-coated rebar reinforcing surrounds (but is not directly attached to) the INVAR rod for horizontal stabilization.

If you are interested in receiving a copy of the Redmond drawing, please e-mail charlier@geology.cwu.edu, or download the REDM drawings as a GIF file.

Materials, Costs and Drawings

 Technical drawing
 Installation costs

Ancillary Equipment

We used Trimble SSI receivers and choke ring antennas with stainless steel recoverable antenna mounts. The antenna mount was modifed from a Mark Smith (JPL) and Frank Wyatt (Scripps) design. The antenna cables are buried and encased in liqutite conduit or liqutite armored cable. The conduit and cables connections are protected by encapsulated shrink tubing.

All of our sites have secure and covered facilities. We use NEMA/EEMAC Type I enclosures with bulkhead fittings. The enclosures contains the GPS receiver, U.S. Robotics 56 kbs modem and heavy duty surge protectors.