DFM Engineering, Inc.
1035 Delaware Ave. Unit D
Longmont, CO 80501
Phone: 303-678-8143
Fax: 303-772-9411

Siderostats & Coeleostats

DFM Engineering has provided five siderostats mounting 0.5 meter aperture flat mirrors. These have been used for the JPL/Keck test bed interferometer and have extremely low jitter in the axis motion and in mirror piston. We have also provided drives for larger systems.


• Extremely low jitter

• 4 degrees per second axes motion

• Mirror front surface located precisely at    the intersection of the axes

• On axis 1 arc second resolution    encoders

• Axes fiducials

• Computer control system

Coeleostats: A ceoleostat is typically a siderostat, but the word is poorly defined. The name may also be used to describe a beam director.

Configurations Summary


Beam Directors

Electro-Optical-Mechanical Systems™ (EOMS™)


Satellite Trackers