Results for “camera design” — Page 41

NASA NTRS2004

Stray Light Lessons Learned from the Mars Reconnaissance Orbiter's Optical Navigation Camera

The Optical Navigation Camera (ONC) is a technical demonstration slated to fly on NASA"s Mars Reconnaissance Orbiter in 2005. Conventional navigation methods have reduced accuracy in the days immediately preceding Mars orbit insertion. The resulting uncertainty in spacecraft location limits rover landing sites to relatively safe areas, away from interesting features that may harbor clues to past life on the planet. The ONC will provide accurate navigation on approach for future missions by measuring the locations of the satellites of Mars relative to background stars. Because Mars will be a bright extended object just outside the camera"s field of view, stray light control at small angles is essential. The ONC optomechanical design was analyzed by stray light experts and appropriate baffles were implemented. However, stray light testing revealed significantly higher levels of light than expected at the most critical angles. The primary error source proved to be the interface between ground glass surfaces (and the paint that had been applied to them) and the polished surfaces of the lenses. This paper will describe troubleshooting and correction of the problem, as well as other lessons learned that affected stray light performance.

stray lights↗

NASA NTRS2018

Measurements of Parachute Dynamics in the World's Largest Wind Tunnel by Stereo Photogrammetry

Between 2012 and 2017, parachutes for four NASA Projects were tested in the 80- by 120-Ft test section of the National Full-Scale Aerodynamic Complex (NFAC) at NASA Ames Research Center. These projects were: (1) Low-Density Supersonic Decelerator (LDSD); (2) Capsule Parachute Assembly System (CPAS, for Orion); (3) Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight, a Mars mission); and (4) Mars 2020. In all tests stereo photogrammetry was used to measure time-dependent positions of features on the canopies. For the LDSD and CPAS tests, where the purpose was to study the trade-off between stability and drag of different parachute designs, the pendulum motion of the canopies about the riser attachment point was measured by calibrated cameras in the diffuser. The CPAS test also included static measurements where the inflated parachutes were pulled to the side by a system of tethers. The Insight tests were structural qualification tests where each canopy was packed in a bag and launched from a mortar. Cameras in the diffuser measured the trajectory of the bag and the stripping of the bag from the canopy. The Mars 2020 test was a workmanship verification test where the canopies were either launched from a mortar or deployed from a sleeve stretched along the tunnel axis. The deployments were recorded from many directions by thirteen high-speed cameras distributed in the diffuser and test section. Photogrammetry was not planned; however, after a tunnel-related accident ended the test prematurely, photogrammetric measurements were bootstrapped from the images to support the accident investigations. This paper describes how the photogrammetry measurements were made in each test and presents typical results.

Schairer, Edward T.↗

NASA NTRS2019

The Inter-Calibration of the DSCOVR EPIC Imager 2 with Aqua-MODIS and NPP-VIIRS

The Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) continuously observes the illuminated disk from the Lagrange-1 point. The EPIC sensor was designed to monitor the diurnal variation of ozone, clouds, aerosols, and vegetation, especially those features that benefit from observation near-backscatter conditions. The EPIC sensor does not contain any onboard calibration systems. This study describes the inter-calibration of EPIC channels 5 (0.44 μm), 6 (0.55 μm), 7 (0.68 μm), and 10 (0.78 μm) with respect to Aqua-MODIS and NPP-VIIRS. The calibration is transferred using coincident ray-matched reflectance pairs over all-sky tropical ocean (ATO) and deep convective cloud (DCC) targets. A robust and automated image-alignment technique based on feature matching was formulated to improve the navigation quality of the EPIC images. The EPIC V02 dataset exhibits improved navigation over V01. Because the visible channels display similar spatial features, a single visible channel can be used to co-register the remaining visible bands. The VIIRS-referenced EPIC ATO and DCC ray-matched calibration coefficients are within 0.3%. The EPIC four-year calibration trends based on VIIRS are within 0.15%/year. The MODIS-based EPIC calibration coefficients were compared against the Geogdzhayev and Marshak 2018 published calibration coefficients and are found to be within 1.6%.

DSCOVR↗

NASA NTRSDate not supplied

The LUVOIR Extreme Coronagraph for Living Planetary Systems (ECLIPS) I: Searching and Characterizing Exoplanetary Gems

Detection and characterization of Earth-like planets around nearby stars using the direct imaging technique is a key scientific objective of future NASA astrophysics flagship missions. As a result, dedicated exoplanet instruments are being studied for the Large UV/Optical/Infrared Surveyor (LUVOIR) and the Habitable Exoplanet Imager (HabEx) mission concepts. In this paper we discuss the Extreme Coronagraph for Living Planetary Systems (ECLIPS) instrument of LUVOIR. ECLIPS will be capable of providing starlight suppression levels of ten orders of magnitude over a broad range of wavelengths in order to detect and characterize the light reflected from potentially Earth-like planets. It will also allow future astronomers to study in great detail the diversity of exoplanets. First, we review the main science drivers and emphasize those that are the most stressing on the instrument design. We then present the overall parameters of the instrument (general architecture and back-end camera). We delve into the details of the static coronagraph masks, which have a significant impact on the scientific productivity of the mission. We discuss the choices the LUVOIR team made in order to maximize the discovery yield of exoEarth candidates. We then present our work on the technological feasibility of such an instrument, focusing in particular on the image stability necessary to achieve ten orders of magnitude of starlight extinction over hours of exposure. We present our error budget and show that using a combination of instrument level (low and high order wavefront sensors) and observatory level telemetry can yield an overall architecture that meets these requirements. Finally, we discuss future technology development efforts that will mature these technologies.

L Pueyo↗

NASA NTRSDate not supplied

The Doppler Wind Temperature Sensor (DWTS) Flight Evaluation and Experiments (TES-16,17)

The Doppler Wind Temperature Sensor instrument (DWTS), developed by Global Atmospheric Technologies and Sciences (GATS), is a powerful yet simple tool with the potential of becoming a new window to upper atmosphere dynamics. Based around a defense-grade infrared camera peering through a static gas cell used as a scanning spectral filter, the DWTS is designed to measure the fingerprints of wind and thermal waves as they propagate to the mesosphere and lower thermosphere. DWTS achieves this scanning by measuring the induced change in the doppler shift of the emission as it passes through the DWTS field of view. DWTS holds promise to aid in more accurate weather determination (Gordley, et al), and the core technology can be easily adapted to study other atmospheres of interest. In partnership with GATS, NOAA, and other collaborators, NASA Ames and the Nano Orbital Workshop group have been working to evaluate the DWTS instrument on orbit and optimize it as a flexible cube satellite payload. The first mission selected for DWTS evaluation is preparing for flight in early 2024, followed by a more capable science mission in 2025, with both missions part of the TES-n/NOW flight series. The first flight, TES-16/DWTS-A, will incorporate a single DWTS instrument in an approximately 2U payload volume with the imaging aperture perpendicular to the flight velocity vector. With an estimated power consumption of 20 watts, supplied via a custom NOW-designed GaN converter, the instrument will maintain the imaging sensor plane at 80K using an integrated pulse-tube cryocooler during instrument evaluation periods. Data from DWTS will be captured via a NOW-designed custom data processor before being transmitted via S-band radio back to select ground stations, with instrument command and control operated via L-band global-coverage radio. After the TES-16/DWTS-A initial demonstration mission, the subsequent TES-17/DWTS-B mission will be a dedicated science mission equipped with three DWTS instruments, each hosting a different gas cell to obtain full altitude coverage from 20 to 200 km both day and night from a single cube satellite. The intention of the flight series, and one of NASA’s interests in the instrument, is to advance a Martian atmospheric instrument (Colaprete, Gordley, et al) which, if successful, would greatly further understanding of Martian atmospheric behavior. The proposed paper will review the flight series in detail, including challenges from the TES-16 flight tests and the projected challenges and application to Mars study. Additional detail regarding the possible applications of a Cognitive Communication technique in current flight development by NOW collaborators at the NASA Glenn Research Center will also be discussed, including the implications of using an automated User Initiated Service (UIS) protocol to maximize the data collected per orbit.

Doppler Wind Temperature Sensor↗

NASA NTRSDate not supplied

Low-Earth Flight Test of an Inflatable Decelerator (LOFTID) Aeroshell Flight Performance

On November 10, 2022, NASA launched the Low-earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) vehicle as a secondary payload mounted inside the launch vehicle adaptor on an Atlas V 401 out of the Vandenburg Space Force Base (VSFB). The primary payload, Joint Polar Satellite System-2 (JPSS-2), was delivered successfully to a sun synchronous trajectory shortly after launch, at which point the Centaur upper stage performed a burn to de-orbit the system. Once on the desired trajectory to enter the atmosphere the top of the payload adaptor was ejected to expose the LOFTID vehicle, then the LOFTID aeroshell, a Hypersonic Inflatable Aerodynamic Decelerator (HIAD), was deployed and inflated without issue. The Centaur pointed the LOFTID to the desired attitude to enter the atmosphere, spun the assembly to three rpm, separated the reentry vehicle, and finally performed a collision avoidance maneuver to prevent the Centaur from re-contacting the LOFTID after atmospheric entry. The LOFTID vehicle maintained the design attitude and spin rate from separation to atmospheric entry, roughly 30 minutes, demonstrating the aeroshell did not experience any energy damping from inflatable structure flexibility. The LOFTID vehicle entered the atmosphere over Alaska at >8km/sec and decelerated as designed demonstrating stable flight from hypersonic entry through subsonic parachute deployment. On-board visible light cameras captured the reactions of the heatshield through all phases of flight and co-located infrared light cameras captured the temperature distribution of the aft side of the heat shield anchored to a distribution of thermocouples on the inflatable structure (IS) in the field of view. Thermocouples were also embedded in the forward side of the aeroshell both in the Flexible Thermal Protection System (FTPS) as well as the IS. This presentation will discuss aeroshell response to the atmospheric entry. The visible light cameras captured mechanical response of the IS to the loads applied in the different phases of entry. Events seen on the visible light cameras correlate with the response of the load cell pins on webbing elements that attach the aeroshell to the centerbody structure. Thermocouple data captured verifies the aerothermal response of the aeroshell was in-kind with pre-flight analysis predictions although some-what lower in most locations. This data will allow the improvement of the aeroshell modeling tools predictive capability. Post-flight inspection of the aeroshell after splash down and ocean recovery shows that all the aeroshell materials and manufacturing techniques developed over the past 15 years of HIAD technology development performed as de-signed at large scale, a scale which cannot be replicated in ground test facilities. The HIAD supported the LOFTID vehicle high in the water after touching down under parachute and maintained buoyancy and integrity for the hour it took to position the recovery vessel near the LOFTID after splash down. There was no indication the HIAD would have experienced an issue maintaining buoyancy for many more hours after water impact as the component maintained adequate inflation pressure more than 12 hours after water extraction with no additional inflation gas in tanks, as the inflation gas remaining in the tank was vented prior to impact. The LOFTID aeroshell was an unqualified success and has opened up opportunities for commercial application.

LOFTID Aeroshell Flight Performance↗

NASA NTRSDate not supplied

Overview and Performance of the LOFTID Instrumentation Suite

On November 10, 2022, NASA launched the Low-earth Orbit Flight Test of an Inflatable Decelerator (LOFTID) vehicle as a secondary payload mounted inside the launch vehicle adaptor on an Atlas V out of the Vandenburg Space Force Base (VSFB). The primary payload, Joint Polar Satellite System-2 (JPSS-2), was delivered successfully to a sun synchronous trajectory shortly after launch, at which point the Centaur upper stage performed a burn to de-orbit the system. Once on the desired trajectory to enter the atmosphere the payload adaptor canister was ejected by the payload adapter separation system to expose the packed LOFTID vehicle, then the LOFTID aeroshell, a Hypersonic Inflatable Aerodynamic Decelerator (HIAD), was deployed and inflated as planned. The Centaur pointed the LOFTID vehicle to the desired attitude to enter the atmosphere, spun the assembly to roughly three rpm, and separated the reentry vehicle. The LOFTID vehicle entered the atmosphere over Alaska at >8km/sec and decelerated as designed demonstrating stable flight from hypersonic entry through subsonic parachute deployment. On-board visible light cameras captured the reactions of the heatshield through all phases of flight, and co-located infrared light cameras captured the temperature distribution of the aft side of the heat shield anchored to a distribution of thermocouples on the inflatable structure (IS) in the field of view. Thermocouples were also embedded in the forward side of the aeroshell both in the Flexible Thermal Protection System (FTPS) as well as the IS. Heat Flux Gages and Pressure Transducers measured the heating rate and surface pressure experienced by the rigid nose of the reentry vehicle. Loadcells measured the interface loads between the IS and the rigid centerbody. This paper will discuss many of the key instruments flown on the successful LOFTID technology demonstration mission and will provide some high level results, while pointing to more detailed papers on the post-flight analyses.

Gregory T Swanson↗

NASA NTRS2016

Design of NEID, an Extreme Precision Doppler Spectrograph for WIYN

We have developed an optical design for a high resolution spectrograph in response to NASA's call for an extreme precision Doppler spectrometer (EPDS) for the WIYN telescope. Our instrument covers a wavelength range of 380 to 930 nm using a single detector and with a resolution of 100,000. To deliver the most stable spectrum, we avoid the use of an image slicer, in favor of a large (195 mm diameter) beam footprint on a 1x2 mosaic R4 Echelle grating. The optical design is based on a classic white pupil layout, with a single parabolic mirror that is used as the main and transfer collimator. Cross dispersion is provided by a single large PBM2Y glass prism. The refractive camera consists of only four rotationally symmetric lenses made from i-Line glasses, yet delivers very high image quality over the full spectral bandpass. We present the optical design of the main spectrograph bench and discuss the design trade-offs and expected performance.

Optics↗

NASA NTRS2000

Design Models for the Development of Helium-Carbon Sorption Crycoolers

We have developed models for predicting the performance of helium-based Joule-Thomson continuous-flow cryocoolers using charcoal-pumped sorption compressors. The models take as inputs the number of compressors, desired heat-lift, cold tip temperature, and available precooling temperature and provide design parameters as outputs. Future laboratory development will be used to verify and improve the models. We will present a preliminary design for a two-stage vibration-free cryocooler that is being proposed as part of a mid-infrared camera on NASA's Next Generation Space Telescope. Model predictions show that a 10 mW helium-carbon cryocooler with a base temperature of 5.5 K will reject less than 650 mW at 18 K. The total input power to the helium-carbon stage is 650 mW. These models, which run in MathCad and Microsoft Excel, can be coupled to similar models for hydrogen sorption coolers to give designs for 2-stage vibration-free cryocoolers that provide cooling from approx. 50 K to 4 K.

Lindensmith, C. A.↗

NASA NTRS2000

Design Models for the Development of Helium-Carbon Sorption Cryocoolers

We have developed models for predicting the performance of helium-based Joule-Thomson continuous-flow cryocoolers using charcoal-pumped sorption compressors. The models take as inputs the number of compressors, desired heat-lift, cold tip temperature, and available precooling temperature and provide design parameters as outputs. Future laboratory development will be used to verify and improve the models. We will present a preliminary design for a two-stage vibration-free cryocooler that is being proposed as part of a mid-infrared camera on NASA's Next Generation Space Telescope. Model predictions show that a 10 mW helium-carbon cryocooler with a base temperature of 5.5 K will reject less than 650 mW at 18 K. The total input power to the helium-carbon stage is 650 mW. These models, which run in MathCad and Microsoft Excel, can be coupled to similar models for hydrogen sorption coolers to give designs for 2-stage vibration-free cryocoolers that provide cooling from approximately 50 K to 4 K.

Lindensmith, Chris A.↗

NASA NTRS1991

Design and fabrication of an autonomous rendezvous and docking sensor using off-the-shelf hardware

NASA Marshall Space Flight Center (MSFC) has developed and tested an engineering model of an automated rendezvous and docking sensor system composed of a video camera ringed with laser diodes at two wavelengths and a standard remote manipulator system target that has been modified with retro-reflective tape and 830 and 780 mm optical filters. TRW has provided additional engineering analysis, design, and manufacturing support, resulting in a robust, low cost, automated rendezvous and docking sensor design. We have addressed the issue of space qualification using off-the-shelf hardware components. We have also addressed the performance problems of increased signal to noise ratio, increased range, increased frame rate, graceful degradation through component redundancy, and improved range calibration. Next year, we will build a breadboard of this sensor. The phenomenology of the background scene of a target vehicle as viewed against earth and space backgrounds under various lighting conditions will be simulated using the TRW Dynamic Scene Generator Facility (DSGF). Solar illumination angles of the target vehicle and candidate docking target ranging from eclipse to full sun will be explored. The sensor will be transportable for testing at the MSFC Flight Robotics Laboratory (EB24) using the Dynamic Overhead Telerobotic Simulator (DOTS).

Grimm, Gary E.↗

DOE OSTI2023

A low noise CMOS camera system for 2D resonant inelastic soft X-ray scattering

Resonant Inelastic X-ray Scattering (RIXS) is a powerful spectroscopic technique to study quantum properties of materials in the bulk. A novel variant of RIXS, called 2D RIXS, enables concurrent measurement of the scattered X-ray spectrum for a wide range of input energies, improving on the typically low throughput of 1D RIXS. In the soft X-ray domain, 2D RIXS demands an X-ray camera system with small pixels, large area, high quantum efficiency and low noise to limit the false detection rate in long duration exposures. We designed and implemented a 7.5 Megapixel back-illuminated CMOS detector with 5 μm pixels and high quantum efficiency in the 200–1,000 eV X-ray energy range for the QERLIN 2D RIXS spectrometer at the Advanced Light Source. The QERLIN beamline and detector are currently in commissioning. The camera noise from in-situ 3 s long dark exposures is 7e - or less and the leakage current is 6.5 × 10 -3 e - /(pixel ∙ s). For individual 500 eV X-rays, the expected efficiency is greater than 75% and the false detection rate is ~1 × 10 -5 per pixel.

47 OTHER INSTRUMENTATION↗

NASA NTRSDate not supplied

Unsteady Pressure Sensitive Paint Camera Calibration Improvements

Data collection using unsteady pressure-sensitive paint (uPSP) has been greatly increased in recent large-scale demonstrations. With this significant increase comes challenges to process this magnitude of data. Techniques designed for several thousands of images collected in a lab do not necessarily scale to millions collected in a production-level system. Novel techniques are needed to meet the tighter requirements imposed on computation time, robustness, and accuracy. This paper outlines a number of such techniques and improvements in regards to the camera calibration process.

Camera calibration↗

NASA NTRS2002

Design and Fabrication of a Two-Dimensional Superconducting Bolometer Array

Large format, two dimensional arrays of close-packed bolometers will enable submillimeter cameras and spectrometers to obtain images and spectra orders of magnitude faster than present instruments. The South Pole Imaging Fabry-Perot Interferometer (SPIFI) for the AST/RO observatory and the Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory will employ a large-format, two-dimensional, closepacked bolometer arrays. Both these instruments are imaging Fabry-Perot spectrometers operating at wavelengths between 100 micron and 700 micron. The array format is 16x32 pixels, using a 32-element multiplexer developed in part for this purpose. The low backgrounds achieved in spectroscopy require very sensitive detectors with NEPs of order 5x10(exp 18) W/square root of Hz. Superconducting detectors can be close-packed using the Pop-Up Detector (PUD) format, and SQUID multiplexers operating at the detector bas temperature can be intimately coupled to them. We have fabricated an engineering model array with this technology which features a very compact, modular approach for large format arrays.

Benford, Dominic↗

NASA NTRS1981

Cartographic potential of a spacecraft line-array camera system - Stereosat

A study of the Stereosat mission, which may acquire analog/digital stereo image data of cartographic quality with linear array camera systems, is presented, with attention given to the Stereosat system and the mission parameters, the utilization of the Stereosat studies in order to indicate the nature and scope of the problems associated with recording image data of high geometric fidelity from spacecraft equipped with line array sensors, and the assessing of the possibilities of meeting the completeness and accuracy requirements of cartographic products. A 713-km circular, sun-synchronous, near polar orbit, with an inclination of 98.24 deg and a repeat cycle of 48 days is designed to insure global coverage of the earth's land masses during the three-year lifetime of the mission. Three cameras (fore, vertical, and aft looking), mounted so as to record stereotriplets for a 61.4 km wide swath at a nominal focal plane scale of 1:1,000,000, are considered. The IFOV of 15 m should be adequate for producing thematic and image maps at scales of 1:50,000 to 1:250,000. The value of the coverage to cartographers will be dictated by the accuracy of the digital image data, which is largely a function of satellite control.

Welch, R.↗

NASA NTRS1988

Planar and finger-shaped optical tactile sensors for robotic applications

Progress is described regarding the development of optical tactile sensors specifically designed for application to dexterous robotics. These sensors operate on optical principles involving the frustration of total internal reflection at a waveguide/elastomer interface and produce a grey-scale tactile image that represents the normal (vertical) forces of contact. The first tactile sensor discussed is a compact, 32 x 32 planar sensor array intended for mounting on a parallel-jaw gripper. Optical fibers were employed to convey the tactile image to a CCD camera and microprocessor-based image analysis system. The second sensor had the shape and size of a human fingertip and was designed for a dexterous robotic hand. It contained 256 sensing sites (taxels) distributed in a dual-density pattern that included a tactile fovea near the tip measuring 13 x 13 mm and containing 169 taxels. The design and construction details of these tactile sensors are presented, in addition to photographs of tactile imprints.

Begej, Stefan↗

DOE OSTI2024

Development of Short-Pulse Laser-Based Diagnostics for Pulsed Power-Driven Warm Dense Matter

This report summarizes a research project conducted at the Physics Department’s Zebra Pulsed Power Laboratory (ZPPL) at the University of Nevada Reno, aimed at developing short-pulse laser-based diagnostics to probe pulsed-power-driven warm dense matter. ZPPL combines a MegaAmpere (MA) pulsed power generator, Zebra, and a relativistic intensity, short-pulse laser, Leopard, offering a unique university-scale platform for high energy density physics, laboratory astrophysics, and inertial fusion energy research. The project focused on establishing a hard X-ray radiographic capability using high-intensity, short-pulse laser-generated X-rays to probe warm dense matter created by the Zebra current. Initial experiments produced X-ray radiographs of a static (cold) aluminum wire using silver and gold foil and wire targets, but intense background radiation from Zebra shots overwhelmed the laser-produced X-rays. To mitigate this, a radiationhardened detector housing was designed and implemented. Additional diagnostic, including a filter stack bremsstrahlung spectrometer and an X-ray pinhole camera, were developed to characterize laser-produced hard X-ray spectra and locate hard X-ray sources in the vacuum chamber. These revealed that strong hard X-rays (> 20 keV) originated near the anode cap, bombarded by energetic electrons. Due to laser unavailability during some experiments, detector performance was successfully tested using hard X-ray sources from the Zebra current, demonstrating their readiness for coupled experiments. The project supported one Ph.D. student (Dr. Lei Chen), who conducted experimental and numerical research, and provided training opportunities and data for three undergraduate senior theses.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

NASA NTRS1979

Ultraviolet astronomy instrumentation for sounding rocket and Shuttle/Spacelab missions

The paper deals with an electrographic Schmidt camera for wide-field imaging and objective-spectrographic sky surveys, and with a nebula spectrograph designed to obtain slit spectra of nebulae and other diffuse sources. Each of these ultraviolet astronomy instruments has been successfully used in sounding rocket flights. It is seen that, with some minor modifications, both instruments should be readily adaptable to Spacelab missions.

Carruthers, G. R.↗