Short Drilled-Braced Monument And Antenna (From RGR Site RG12 In New Mexico)

The short drilled-braced GPS monument consists of four stainless-steel rods that are set in solid bedrock (drilled and epoxied to a depth of about one yard). The GPS antenna is placed on the apex of the construction and is covered/protected by a locking plastic dome, as shown here. These monuments are designed to be highly stable against soil creep and other near-surface motions. SDB monuments are usually intended to be permanent installations, and we made every effort to find locations where we will have the option to continue making measurements after the NSF-funded Rio Grande Rift Project ends in 2010. More information on the design and construction of short drilled-braced monuments can be found here.

Single Mast Monument And Antenna (From RGR Site RG16 In Colorado)

The single mast GPS monument consists of a single stainless-steel pipe that is set vertically in solid bedrock (drilled and epoxied to a depth of about one yard). The GPS antenna is placed atop the pipe and covered/protected by a locking plastic dome, as shown.

We used the single mast monument in relatively remote locations where there was no vehicle access. Although the short-drilled braced monument is generally considered to be more stable than a single mast, the SDB requires arc welding powered by a generator that cannot be carried over distances greater than a few hundred feet.

Stainless Steel Instrument Box And Solar Panels (From RGR Site RG12 In New Mexico)

The stainless steel instrument box holds the GPS instrument, batteries and various wires and cables. It is affixed to a pole that is firmly planted in the ground and topped with a solar panel for power. At some of our sites (e.g., RG20), this construction weathered months of subzero temperatures and winds in excess of 100 mph without power failure or equipment problems.