The increase in efficiency by using the modern servo motors
will result in a considerable reduction in the costs to operate the antennas. At the Fairbanks site,
the electrical connect and usage cost savings are estimated to pay for the upgrade in a few years.
The new electrical servo motor drive system also has favorable environmental effects. The noise
is highly reduced as the new servo system is very quiet. Also, the hydraulic system components are
nearing their useful life. If a hydraulic component has a catastrophic failure, it could very easily
result in a massive spill of hydraulic oil requiring a very expensive cleanup.
The new drive system will be controlled by an industrial PC. The PC allows automatic downloading
of satellite ephemeris data in three different data formats from web site databases. The software
propagates the satellite ephemeris data and converts it to the proper mount angles and velocities
to drive the antenna to track the desired satellite. The antennas can track not only geosynchronous
satellites (which is very easy), but can also track polar low orbit satellites and satellites that
are in very high and elongated orbits. The control system also allows auto tracking where position
information from the radio signal is used to provide position corrections to the antenna drives.
The NOAA control system builds on DFM Engineering's experience of driving the antennas at PARI to
acquire and track stars. The software will be expanded to allow tracking satellites and incorporates
other features to interface with the existing station operations. DFM Engineering was chosen because
of our proven capabilities of providing control system retrofits to similar antennas and optical
telescopes. The DFM proposal was deemed to be technically superior to the other proposals received
and also was priced slightly lower in cost.
The Wallops NOAA Station antenna upgrade
will be installed in April, 2003.
The Fairbanks NOAA Station installation
will be performed in August, 2003.
Related stories and products:
DFM Control System Upgrade at PARI
DFM TCS (Telescope Control System)
PARI (Pisgah Astronomical Research
NOAA (National Oceanographic and Atmospheric
Wallops NOAA Station
Fairbanks NOAA Station