October 2002 Meeting
Fast Tracking at Trex
Talk: Trex has developed two innovative infrared
tracking systems, the Rapid Optical Beam Steering (ROBS) system and
the Fast InfraRed Sniper Tracker (FIRST). FIRST utilizes some of the
innovations originally built into the ROBS.
The ROBS was developed by Trex beginning in 1986 for
BMDO and the Navy as a prototype 0.5 meter aperture, wide-angle, multiple
target detection, tracking, and imaging system with laser ranging
capability. The ROBS uses two separate InSb cameras both at 3-5 microns
and separate apertures for acquisition and tracking while FIRST uses
the same camera and changeable optical path. The acquisition camera
for ROBS has a 2 cm aperture, similar to that used for FIRST in acquisition
mode. For tracking, the ROBS system uses a separate camera and large
aperture (0.5 m), the FIRST uses a 6cm aperture and the same camera.
ROBS is based on an innovative telescope design featuring an oversize
primary and a lightweight, moveable secondary assembly. The secondary
assembly can be moved very precisely (few microradians precision)
and very fast (~ 1,000 radians/sec2) over a wide field of 24 degrees.
The ROBS has tracked up to 4 targets simultaneously.
A new version of the ROBS, 3DATA, is being completed
and will have a number of new features, including capability to track
up to 20 targets per second, simultaneously. The FIRST has been demonstrated
to track a bullet (0.50 caliber) The FIRST has a dramatically different
optical head, resembling a periscope with the first mirror (flat)
controlled by two direct drive motors, providing elevation and azimuth
control at accelerations up to 40,000 radians/sec2. Details of the
design and performance will be presented.
Speaker: Dr. Paul Fairchild received a Ph.D.
in chemistry from the University of California in 1980 and was a Post
Doctoral associate at Cornell University (1980-1981) and SRI International
(1981-1983). He has worked as a staff scientist at TRW (1983-1988)
and has been a senior scientist at Trex Enterprises since 1988. The
last few years at Trex he has been in the Laser Radar Group. His main
interests have been in the areas of laser imaging and laser radar.
Most recently he has been the manager of a program (3DATA) to develop
a 3-Dimensional acquisition and tracking system for use by the Air
Force in rapidly retargeting and tracking multiple targets.
Meeting Review:
October 2002 Meeting of the OSSD at Trex Enterprises
by Graham Brewis, Allied Optical Corp.
The October meeting of the OSSD held at Trex Enterprises
was well attended and audience participation was lively. Paul Fairchild
gave a thorough overview of their Rapid Optical Beam Steering (ROBS)
system and Fast InfraRed Sniper Tracker (FIRST) using a PowerPoint
presentation. This was followed by a “hands on” tour of the two systems
where both Paul and Suzanne Montgomery answered many questions about
the mechanical hardware, design tradeoffs, and the funding process
for such developments.
Paul’s presentation covered the optical design of the
present ROBS system as well as the new version of ROBS, 3DATA . Actual
tracking of planes was presented in a video clip. An example of a
FIRST system that was in the same room as the ROBS system was available
to be scrutinized. This unit allowed the attendees to examine in reasonable
detail the mechanical design used to accomplish the rapid scanning
required to track rifle bullets.
OSSD meetings held in the past at Trex featured the
ROBS platform actively tracking simulated targets. Watching the mirror
mount jump around gives the observer an appreciation of the technical
challenges that had to be overcome in order for the system to work
reliably. The system was being upgraded at the time of this meeting
and could not be turned on. We were informed that the current optical
design for both systems was laid out using Zemax and the mechanical
design was done using SolidWorks.
