4 research outputs found
System to Perform Radio Frequency Interferometry Using Optical Fiber Sensing Signal Processing Techniques
Aspects of the present disclosure involve a system and method for performing radio frequency interferometry using optical fiber sensing. Optical fiber sensing is performed as a reference signal is defined and compared, in the optical domain, to incoming signals to obtain interference fringe patterns that can be used to decode phase shift offsets with respect to the designated reference signal. The phase shift offsets can be determined by first optically modulating the reference and incoming signals using a laser source as the carrier. In the optical domain, the reference and incoming signals are combined using an optical coupler and then converted back to the electrical domain for processing
Space Flight LiDARs, Navigation & Science Instrument Implementations: Lasers, Optoelectronics, Integrated Photonics, Fiber Optic Subsystems and Components
For the past 25 years, the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center's Photonics Group in the Engineering Directorate has been substantially contributing to the flight design, development, production, testing and integration of many science and navigational instruments. The Moon to Mars initiative will rely heavily upon utilizing commercial technologies for instrumentation with aggressive schedule deadlines. The group has an extensive background in screening, qualifying, development and integration of commercial components for spaceflight applications. By remaining adaptable and employing a rigorous approach to component and instrument development, they have forged and fostered relationships with industry partners. They have been willing to communicate lessons learned in packaging, part construction, materials selection, testing, and other facets of the design and production process critical to implementation for high-reliability systems. As a result, this successful collaboration with industry vendors and component suppliers has enabled a history of mission success from the Moon to Mars (and beyond) while balancing cost, schedule, and risk postures. In cases where no commercial components exist, the group works closely with other teams at Goddard Space Flight Center and other NASA field centers to fabricate and produce flight hardware for science, remote sensing, and navigation applications. Summarized here is the last ten years of instrumentation development lessons learned and data collected from the subsystems down to the optoelectronic component level
On-sky single-mode fiber coupling measurements at the Large Binocular Telescope
The demonstration of efficient single-mode fiber (SMF) coupling is a key
requirement for the development of a compact, ultra-precise radial velocity
(RV) spectrograph. iLocater is a next generation instrument for the Large
Binocular Telescope (LBT) that uses adaptive optics (AO) to inject starlight
into a SMF. In preparation for commissioning iLocater, a prototype SMF
injection system was installed and tested at the LBT in the Y-band (0.970-1.065
m). This system was designed to verify the capability of the LBT AO system
as well as characterize on-sky SMF coupling efficiencies. SMF coupling was
measured on stars with variable airmasses, apparent magnitudes, and seeing
conditions for six half-nights using the Large Binocular Telescope
Interferometer. We present the overall optical and mechanical performance of
the SMF injection system, including details of the installation and alignment
procedure. A particular emphasis is placed on analyzing the instrument's
performance as a function of telescope elevation to inform the final design of
the fiber injection system for iLocater.Comment: 11 pages, 7 figure
iLocater: a diffraction-limited Doppler spectrometer for the Large Binocular Telescope
We are developing a stable and precise spectrograph for the Large Binocular
Telescope (LBT) named "iLocater." The instrument comprises three principal
components: a cross-dispersed echelle spectrograph that operates in the
YJ-bands (0.97-1.30 microns), a fiber-injection acquisition camera system, and
a wavelength calibration unit. iLocater will deliver high spectral resolution
(R~150,000-240,000) measurements that permit novel studies of stellar and
substellar objects in the solar neighborhood including extrasolar planets.
Unlike previous planet-finding instruments, which are seeing-limited, iLocater
operates at the diffraction limit and uses single mode fibers to eliminate the
effects of modal noise entirely. By receiving starlight from two 8.4m diameter
telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise
to overcome the limitations that prevent existing instruments from generating
sub-meter-per-second radial velocity (RV) precision. Although optimized for the
characterization of low-mass planets using the Doppler technique, iLocater will
also advance areas of research that involve crowded fields, line-blanketing,
and weak absorption lines.Comment: 13 pages, 11 figure