What's where on Mauna Kea

Here at UCO/Lick Observatory we build instruments. Originally we built for the telescopes at Lick Observatory on Mt. Hamilton (east of San Jose, California). Lately we added the UCO part to our name, and we have also been building instruments for the telescopes at Keck Observatory on Mauna Kea (the big island of Hawaii). Having spent some effort determining what is where on Mt. Hamilton, it became time to do the same for Mauna Kea.

The 7.5 minute USGS topographic quadrangle for Mauna Kea is available online. Unfortunately, many of the observatories have been built subsequent to the most recent update some 20 years ago.

The observatories on Mauna Kea do not share the geodetic favor that was so helpful on Mt. Hamilton. The environment on Mauna Kea is not conducive to casual geodetic occupation, and the few surrounding peaks of equal size are similarly difficult. Nevertheless, the NGS provides a wonderful resource that permits the inspection of the data sheets for all the reference marks in the US, including those on the Mauna Kea summit.

Putting these bits of information together creates this map. Each of the control points from the NGS data sheets is marked. The approximate location of most of the telescopes are also marked. The VLBA antenna is conspicuously absent, but it is located off the image approx. 2km south-southeast of the summit at the 12200 foot level.

From scaling this map I estimate that the position of Keck I is
W 155:28:28.8
N 19:49:35.0
using the 1983 North American Datum.
Because Keck is not marked on the quadrangle, these positions could be wrong by as much as an arcsecond. A much better set of positions for most everything is at the IFA web site.

Several aspects of these data need to be emphasized.

A significantly more reliable scaling could be performed by using site maps from the construction of the new domes. In more hospitable locations the sorts of maps which show the layout of underground utilities and roadways are usually tied to survey marks. These are typically found in blueprint rooms and on file at county permit offices.
Steve Allen <sla@ucolick.org>
UCO/Lick Observatory
University of California
Santa Cruz
, CA 95064

Phone: +1 831 459 3046
FAX: +1 831 459 2298