Keyword: Telescopes

Briefs: Photonics/Optics
Algorithm for Estimating PRC Wavefront Errors from Shack-Hartmann Camera Images

Phase retrieval (PR) and Shack-Hartmann Sensor (SHS) are the two preferred methods of image-based wavefront sensing widely used in various optical testbeds, adaptive optical systems, and ground- and space-based telescopes. They are used to recover the phase...

Briefs: Software
Large Computer-Generated Hologram with Software-Generated Calibration Wavefront Map

This technology enables accurate calibration of a large Computer Generated Hologram (CGH) fabricated without great accuracy, such that the CGH still measures an aspheric surface to an excellent accuracy of a couple of nm rms. The goal is the creation of software...

Briefs: Information Technology
JWST IV&V Simulation and Test (JIST) RT Logic T501 Emulator

In order to develop a software-only test environment for the James Webb Space Telescope (JWST) mission, a solution was needed to send commands and receive telemetry between the TCTS (Telemetry and Command Test Set) and CMM-S card. The as-is solution requires the utilization of...

Articles: Photonics/Optics

In the past decade, diode lasers have made great strides in both power and reliability. The performance improvements have enabled new applications, particularly in areas where...

Briefs: Photonics/Optics
Monolithic Dual Telescope for Compact Biaxial Lidar

A document discusses the Ultra Compact Cloud Physics Lidar, a biaxial lidar with a narrow receiver field of view. It requires tight optical alignment between the transmitter and receiver paths while flying on various aircraft over various temperatures and in the presence of vibration. To...

Briefs: Physical Sciences
Alternating Magnetic Field Forces for Satellite Formation Flying

Orbiting a large number of satellites in fixed formations will be critical to many future space missions, especially large-scale interferometers, telescopes, antennas, and gravity wave detectors. Consequently, extensive research has been devoted over the last 20 years to formation...

Briefs: Electronics & Computers
Microelectronic Repair Techniques for Wafer-Level Integration

Wafer-level integration was employed to mount the microshutter array for the James Webb Space Telescope (JWST) and the detector-read-out hybrid for TIRS (Thermal Infrared Sensor). In the case of the JWST substrate, two conductors (polysilicon and aluminum) separated by a silicon oxide...

Briefs: Physical Sciences
Measurement of Cryogenic Fluid Level with Laser Propagation and Surface Floor Reflection

The risks associated with introducing new hardware and methods into an operational environment have in part prohibited cryogen level measurement technology from advancing. In prior art, measurements have been made with invasive probes immersed in the...

Briefs: Photonics/Optics
Solar Pumped Fiber Laser for Solar Sail Propulsion and Remote Power Transfer

A new method has been developed to create coherent laser light efficiently with direct optical coupling of the Sun’s energy into the gain medium for multiple uses. New advances in solar cell photovoltaic (PV) technologies have greatly improved their efficiencies,...

Application Briefs: Imaging
CMOS imager engineering units
SRI International
Menlo Park, CA
650-859-2000
www.sri.com

SRI International, working with TowerJazz (Newport Beach, CA), has...

Briefs: Physical Sciences
Preparation, Planning, and Concept Demo of a Technique to Find ≈7-to-10-m Near Earth Asteroids

A paper describes a new technique designed to increase significantly the sensitivity for finding and tracking small, dim, and fast-moving near Earth asteroids (NEAs). The technique relies on a combined use of a novel data processing approach and a...

Briefs: Information Technology
Picoradian Staring Astrometry Using a Simple Staring Telescope

A document describes solutions to problems of astrometry at the microarc-second (picoradian) level using a simple staring telescope. The problems include field-dependent beam-walk on the telescope’s mirrors, pixel position irregularity and distortion over time, non-flat intra-pixel...

Briefs: Physical Sciences

Typically, the cost of a space observatory is driven by the size and mass of the primary aperture. Generally, a monolithic aperture is much heavier and...

Briefs: Information Technology
Slot-Sampled Optical PPM Demodulation

In order to demodulate an optical PPM signal, the receiver must align its slot clock to that of the received waveform to count the number of arrivals within each slot. The large bandwidth expansion factor of PPM, M/log2(M) requires a prohibitively large sample rate when a fixed sample clock N...

Briefs: Physical Sciences
High-Speed Spectral Mapper

The Hyperspectral Infrared Imager (HyspIRI) spaceborne mission has two imaging sensors operating in the visible to shortwave infrared (VSWIR) and the thermal infrared (TIR), respectively. The HyspIRI-TIR imaging instrument is being developed for infrared mapping of the Earth in 8 spectral bands with a 5-day revisit...

Briefs: Test & Measurement
Application of a Physics-Based Stabilization Criterion to Flight System Thermal Testing

This innovation consists of a procedure and set of equations that allows thermal balance steady-state temperatures to be predicted hours before the balance is reached based on current temperature and rate-of-change measurements. This will allow tests to run...

Briefs: Test & Measurement
JWST IV&V Simulation and Test (JIST) Solid State Recorder (SSR) Simulator

As described in “JWST Integrated Simulation and Test (JIST) Core” (GSC-16739-1) on page 25, the JIST system is a software-based simulator that uses the James Webb Space Telescope (JWST) operational ground system, ground system command/telemetry databases, simulated...

Briefs: Software
Orbital Debris Engineering Model (ORDEM) v.3

A model of the manmade orbital debris environment is required by spacecraft designers, mission planners, and others in order to understand and mitigate the effects of the environment on their spacecraft or systems. A manmade environment is dynamic, and can be altered significantly by intent (e.g., the...

Briefs: Mechanical & Fluid Systems
Lightweight Liquid Helium Dewar for High-Altitude Balloon Payloads

Astrophysical observations at millimeter wavelengths require large (2-to-5- meter diameter) telescopes carried to altitudes above 35 km by scientific research balloons. The scientific performance is greatly enhanced if the telescope is cooled to temperatures below 10 K with no...

Briefs: Physical Sciences
JWST Integrated Science Instrument Module Alignment Optimization Tool

During cryogenic vacuum testing of the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM), the global alignment of the ISIM with respect to the designed interface of the JWST optical telescope element (OTE) will be measured through a series of...

Briefs: Physical Sciences
Partially Transparent Petaled Mask/Occulter for Visible-Range Spectrum

The presence of the Poisson Spot, also known as the spot of Arago, has been known since the 18th century. This spot is the consequence of constructive interference of light diffracted by the edge of the obstacle where the central position can be determined by symmetry of the...

Briefs: Test & Measurement
A System for Measuring the Sway of the Vehicle Assembly Building

A system was developed to measure the sway of the Vehicle Assembly Building (VAB) at Kennedy Space Center. This system was installed in the VAB and gathered more than one total year of data. The building movement was correlated with measurements provided by three wind towers in...

Briefs: Mechanical & Fluid Systems
Mechanism for Deploying a Long, Thin-Film Antenna From a Rover

Observations with radio telescopes address key problems in cosmology, astrobiology, heliophysics, and planetary science including the first light in the Universe (Cosmic Dawn), magnetic fields of extrasolar planets, particle acceleration mechanisms, and the lunar ionosphere. The Moon...

Briefs: Software
Implementation of a Wavefront-Sensing Algorithm

A computer program has been written as a unique implementation of an image-based wavefront-sensing algorithm reported in “Iterative-Transform Phase Retrieval Using Adaptive Diversity” (GSC-14879-1), NASA Tech Briefs, Vol. 31, No. 4 (April 2007), page 32. This software was originally intended...

Briefs: Physical Sciences
Submillimeter Planetary Atmospheric Chemistry Exploration Sounder

A report describes the Submillimeter Planetary Atmospheric Chemistry Exploration Sounder (SPACES), a highsensitivity laboratory breadboard for a spectrometer targeted at orbital planetary atmospheric analysis. The frequency range is 520 to 590 GHz, with a target noise temperature...

Briefs: Physical Sciences
Recirculating 1-K-Pot for Pulse-Tube Cryostats

A paper describes a 1-K-pot that works with a commercial pulse tube cooler for astrophysics instrumentation testbeds that require temperatures

Application Briefs: Photonics/Optics

In biological imaging, the object of interest is not always in plain sight. This is especially true when performing microscopy of cells buried deep within tissues. The tissues...

Briefs: Physical Sciences
Hyperspectral Imager-Tracker

The Hyperspectral Imager-Tracker (HIT) is a technique for visualization and tracking of low-contrast, fast-moving objects. The HIT architecture is based on an innovative and only recently developed concept in imaging optics. This innovative architecture will give the Light Prescriptions Innovators (LPI) HIT the...

Briefs: Physical Sciences
Planar Superconducting Millimeter-Wave/Terahertz Channelizing Filter

This innovation is a compact, superconducting, channelizing bandpass filter on a single-crystal (0.45 μm thick) silicon substrate, which operates from 300 to 600 GHz. This device consists of four channels with center frequencies of 310, 380, 460, and 550 GHz, with...