Monument Pins

Back to comparison table	Mount Commonly Used	Stability	Cost	Install Time	Labor	Substrate	Site Impact
	campaign GPS/GNSS antenna mount	med-high	$15-50	<1 hr	1	BR, R	low

 
Danish geodetic marker near Kangerlussuaq, Greenland (left); simple stainless steel pin at site DOIW in Afar, Ethiopia (right).

Pros

• Inexpensive (e.g. $15-50, depending on marker design)

• Can be installed with a battery-powered drill

• Small footprint, low profile

• Short installation time (<1 hr, can be as little as 15 minutes)

• Materials and machining are available in most cities

• Can be installed on a rooftop or other stone or cement structure

• Can be occupied with a wide variety of antenna mounts

Cons

• Can only be installed in solid material

• Must be occupied with a temporary antenna mount

Design and Construction

There are a variety of marker designs. In general, markers consist of a post with a 1 mm dimple or intersecting crosshairs on top. The marker most commonly used by UNAVCO is the dimpled monument pin, or "Bevis pin." The Bevis pin is a 6-inch long, 1/2-inch diameter stainless steel pin machined with notches on the sides to prohibit rotation and a 1 mm dimple on the top. Machine and installation instructions are given below.

Bevis pin machining instructions (.pdf)

Bevis pin installation instructions (.pdf)

Approximate Cost

$15-50; varies depending on marker design.

Materials

• pin

• epoxy or quick-setting, expansive concrete and water

Tools

• battery-powered drill

• tube to blow rock flour out of the hole

• level (optional but preferable)

• needle-nosed pliers for rescuing pins from over-drilled holes (recommended)

Mount Commonly Used

         

Many mounts can be used with a monument pin, including the Tech 2000 mast, UNAVCO fixed-height spike mount, standard, short, or fixed-height tripod, or bipod. See the UNAVCO Resources: GNSS Antenna Mounts page.

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