DFM Engineering, Inc. is the premier astronomical telescope manufacturer in the United States. We have manufactured and installed over 100 professional astronomical telescopes worldwide including telescopes located in Australia, Chile, China, India, Germany, Greece, and South Africa. We have also retrofitted our Telescope Control System (TCS) on over 40 older telescopes manufactured by other firms during our 45+ years of serving the astronomical community. Our control system and it's predecessors are used on more professional telescopes than any other control system worldwide.
DFM Engineering has built over a hundred professional astronomical telescopes with equatorial fork mounts with apertures ranging from 0.4-m to 2.4-m. Presently we are finishing our tenth 52-inch (1.3-M) aperture telescope. These telescopes use friction drives (sometimes called roller drives) to produce high stiffness and very smooth tracking. We also have considerable experience with direct drive telescopes where the drive motors are located on each axis.
In addition to our traditional telescope product line, DFM Engineering has extensive experience manufacturing custom telescopes, including ATLAS (the Killer Asteroid Survey), and satellite trackers.
SPACE SITUATIONAL AWARENESS:
Trusted by the US government and industry for over 45 years, DFM offers world-leading technology for accurate tracking of satellites, debris, and objects in all orbital regimes. DFM Engineering is a global leader in the design and manufacture of systems for Space Domain Awareness (SDA) and space control. With high fidelity tracking, actions in space are captured in detail. Our state-of-the-art optical manufacturing and testing facility is experienced at producing the highest quality complete optical systems required for demanding Space Situational Awareness (SSA) applications. It is DFM's extensive experience with electro-optical surveillance capabilities and their necessary sensors that will make your custom SSA project a success.
DFM Engineering's extensive portfolio of best-in-class designs led us to develop DFM's new flagship product, The LEO Scope™. Optimized for scaled deployment, The LEO Scope™ offers humanity hope for the future to address the dire need for additional Space Situational Awareness (SSA) satellite tracking Optical Ground Stations (OGS) in consideration of the ever increasing fleet of satellites being deployed.
Featuring the highest performance/cost of all commercially available satellite tracking Optical Ground Stations (OGS), the LEO Scope™ has 26-inch (66cm) aperture optics based upon our ATLAS design, with the telescope / camera offering F/1.7, 4.4-degree FOV, and a Ximea Gpixel GSENSE6060 cMOS camera (6144 x 6144 with 10µm square pixels 61-mm x 61-mm, 86.8-mm diagonal). This OGS offers low inertia and high stiffness to track at LEO rates which can exceed 10-degrees per second. 14th magnitude stars are easily detected in less then a tenth of a second exposure. Two degree step and settle performance of +/- 1.5 arc seconds within one second. The OTA accepts a single filter, or DFM's Filter Cassette Changer System utilizing an 8-position filter cassette. These 125-mm X 125-mm research-grade filters, when integrated with 3 or more telescopes that form a networked array, allow for real-time imaging in color for full-frame Space Object Identification (SOI), a vital capability for SSA.
In addition to addressing SSA needs, the LEO Scope™ was also designed to offer the first practical platform for a optical communications ground station. Built upon our industry proven technologies coupled with DFM's patent-pending optical design, our cost-effective optical communication terminal will enable large amounts of secure data to be transmitted over long distances at the speed of light. Our LEO Comm™ will construct the data highways necessary to eliminate existing barriers of connectivity.
Currently, the entire optical communication ground station marketplace is in the prototype phase. DFM Engineering is entering an exciting new phase bringing our technology to market with our partners and customers. DFM Engineering will be implementing optical communication as a key enabler of our commercial business model going forward.
During the past 20 years, observatory design has evolved. Much has been learned about how the observatory affects the image production of the telescope (dome "seeing" ). Modern observatory design stresses reducing heat sources within the observatory and promoting good ventilation. Keeping the telescope and surrounding area at the night time outside ambient temperature is essential for good images.
An often neglected aspect of observatory design is "dome seeing," a term encompassing how the design and construction of the dome (and the surrounding structure) affects the delivered image quality. During nighttime viewing, the air is usually cooler than any structures of significant mass. This causes the air inside and immediately surrounding the dome to be warmer than the ambient air temperature. When the dome shutter is opened, a stack effect (or chimney effect) causes the warmer air in the dome to vent out of the shutter, a turbulent flow then mixes warm and cool air. Because of the shutter's limited area, the air distortion is concentrated directly in the line-of-sight of the telescope.
Heat sources within the dome include, the telescope, the instruments, people, and thermal mass. External heat sources include solar heating and hot air infiltration. Ventilation is only one step towards bringing about temperature equilibrium and it needs to be directed appropriately. With an array of temperature sensors, DFM Engineering can test and analyze various techniques to reduce the effect of dome seeing.
DFM can recommend what combination of insulation, ventilation, and forced convection need be implemented to address existing problems. By taking into account the prevailing winds, dome layout, and various heat sources and their time constants, a proper solution can be chosen to significantly reduce dome seeing issues.
DFM Engineering has the skills necessary to help you drastically improve the seeing ability of your existing telescope installation. After working with many architects over the last 40 years, we understand the limitations architects have in building a high-performance observatory. Due to this, we have designed our own observatory building that not only offers excellent performance, but it also integrates all the support equipment necessary to easily service your telescope. We have three different sizes available, all of which have been previously built to assure that they perform to DFM standards.
SUMMARY OF OUR STANDARD TELESCOPE FEATURES:
DFM Engineering telescopes use state-of-the-art friction drives that are very efficient, require very little power, and dissipate very little heat in the observatory. The equatorial fork mount provides a convenient and compact telescope capable of carrying a large instrument load and requires minimal counterweights for fast, dynamic response.
We offer Renishaw 26-bit absolute encoders to provide telescope pointing information for all new telescopes AND for our older telescopes with an optional upgrade. These modern encoders simplify initialization of the telescope position system and provide very accurate pointing-typically better than 10 arc seconds RMS on the sky above a zenith distance of 70-degrees.
Our current The Telescope Control System (TCS) provides a user-friendly interface to the telescope. Using a industrial rack mount custom Motor Driver Chassis (MDC) to provide the telescope control functions, TCSGalil™ runs connected to a Microsoft Windows operating system environment allowing use of many third party software packages that provide graphical user interfaces (GUI) such as "TheSky", "CCD Soft", and "Orchestrate" from Software Bisque and similar programs running under the ASCOM platform. TCSGalil™ becomes a peripheral to your computer system, allowing integration with your own observing program.
Our astronomical optics are made from near zero expansion materials such as ZeroDur, Astrosital, ULE, or TSG. The optics are supplied with interferograms of the optical shop testing and the testing is performed in autocollimation. The data is presented as wavefront error for the all-up optical system. All optics are mounted within removable mirror cells. The primary mirror cell may be easily removed from the telescope using the mirror handling tools supplied. Disassembly of the telescope is not needed for routine mirror service.
DFM’s big iron telescope approach is designed for high positioning accuracy and ultra-smooth tracking with large instrument payloads and makes Nasmyth and Coudé configurations and their associated wavelength focus issues a thing of the past.
DFM Engineering can also provide instrumentation such as filter wheels, off axis guide probes, auto guiders, spectrographs, and commercially available CMOS and CCD cameras. Check out our Products page for more information.