| A joint research program was developed by the U.S. Geological Survey,
NASA - JPL, California Institute of Technology, and Ashtech Technology,
Inc. to study the earth's movements as a possible predictor of
earthquakes. By using GPS and microwave technology, movements of
the earth's surface as little as 5mm vertically and 3mm horizontally can
be detected and recorded. The key to measuring the earth's
movements is Ashtech Technology's system.
The Ashtech choke-ring antenna is
identical to the U.S. Government-sponsored antenna design structure in
physical, electrical, multipath and phase center properties. The
antenna consists of a choke-ring ground plate with five concentric ring
assemblies, a Dorne & Margolin dipole antenna element (100% IGS
compatible), an Ashtech proprietary Low Noise Amplifier (LNA) and a
large dome covering the entire antenna for added |
protection
from foreign particles. The antenna is ideal when used in
combination with the Ashtech Z-12 GPS receiver for precise geodetic applications.
The original manufacturing method used to produce
the antenna was to "hog out" the configuration from a solid
block of 6061-T6 aluminum measuring 16"x16"x5"
thick. This method was very expensive, costing $507 per part.
Under the direction of Bob Watkins, Manufacturing
Engineering Manager, Ashtech approached SKS for a feasibility study on
die casting the antenna. Although the initial cost analysis
indicated that the die-cast tooling would cost $59,000, the good news
was that tooling costs would be fully amortized after the production of
only 150 parts. each part could now be manufactured for just $112,
a cost saving of $395 per unit. |