Michael Maszkiewicz

Development of compact and low distortion imaging spectrometer for Mars missions and airborne aerial vehicles

The paper describes a joint development of a compact and low distortion imaging spectrometer system for future Mars sample return mission and unmanned aerial vehicles under the collaboration between the Canadian Space Agency and Defence Research and Development Canada. A Dyson design was selected as the imaging spectrometer due to its compactness, high optical output and low distortion. After briefly describing the requirement of the imaging spectrometer system, the preliminary results of the design of the Dyson spectrometer were reported.

Hyperspectral Environment and Resource Observer (HERO) mission

The Canadian Space Agency (CSA) has conducted mission and payload concept studies in preparation for launch of the first Canadian hyperspectral Earth observation satellite. Named the Hyperspectral Environment and Resource Observer (HERO) mission, its objective is to provide information-rich optical imagery that enhances decision-making and stewardship of sensitive ecosystems and natural resources. The mission is designed to provide accurate forest inventory and health information, map the geology of the north, assess environmental impacts, and strategically extend the Canadian investment in Earth observations. The mission builds on the Canadian industry experience and expertise in satellite development and remote sensing and will make new capabilities available for a wide variety of users worldwide. In 2005, the preliminary system requirement review (PSRR) and phase A (preliminary mission definition) were concluded. The resulting mission characteristics are a swath width greater than 30 km, a ground sampling distance of 30 m, a spectral range from 400 to 2500 nm, and a spectral sampling interval of 10 nm. HERO is primarily a flexible tasking mission with a raw capacity of ~600 000 km2 daily ground area coverage. Large-area mapping is to be performed as a background mission. The proposed instrument design consists of dual spectrometers and telescope assemblies. The fore-optics is composed of a three-mirrors anastigmatic (TMA) telescope. The Offner-type spectrometers have separate visible near infrared (VNIR) and short-wave infrared (SWIR) detectors. Expected performance includes a signal-to-noise ratio (SNR) of 600:1 in the VNIR and 200:1 in the SWIR, F/2.2 spectrometers with minimized smile and keystone, and instrument modulation transfer function (MTF) of at least 0.3 at the Nyquist frequency for all wavelengths and fields.

Optical communications between moving transceivers using double phase-conjugation beam tracking

Theoretical and experimental studies of double phase conjugation of two nearly opposite optical beams in a nematic liquid crystal with thermal optical nonlinearity are presented. A theoretical model describing wave coupling and interactions with the material is applied to define conditions for thermal-nonlinearity double phase conjugation. Experimentally, double phase conjugation of two independent laser beams at 1500 nm has been demonstrated in a stack of nematic liquid crystal layers with absorptive coatings on layer’s walls. The experimental observations have been in good agreement with theoretical predictions. Signal transmission, beam-jitter compensation and beam tracking, realized with a double phase-conjugation mirror, have been demonstrated in a modeling experiment using simulated transmitters’ movements.

Ambient optomechanical alignment and pupil metrology for the flight instruments aboard the James Webb Space Telescope

While efforts within the optics community focus on the development of high-quality systems and data products, comparatively little attention is paid to their use. Our standards for verification and validation are high; but in some user domains, standards are either lax or do not exist at all. In forensic imagery analysis, for example, standards exist to judge image quality, but do not exist to judge the quality of an analysis. In litigation, a high quality analysis is by default the one performed by the victorious attorney’s expert. This paper argues for the need to extend quality standards into the domain of imagery analysis, which is expected to increase in national visibility and significance with the increasing deployment of unmanned aerial vehicle—UAV, or “drone”—sensors in the continental U. S.. It argues that like a good radiometric calibration, made as independent of the calibrated instrument as possible, a good analysis should be subject to standards the most basic of which is the separation of issues of scientific fact from analysis results.

Development of advanced miniaturized Dyson imaging spectrometer for Mars rover and small aircraft

The Canadian Space Agency and the Defence Research and Development Canada are jointly developing an advanced miniaturized imaging spectrometer for future Mars rover and onboard a small aircraft. This work is the further development of the two previous concept studies for Mars: Canadian Hyperspectral Imager for Mars Exploration and Resource Assessment (CHIMERA) and Hyperspectral and Luminescence Observer (HALO). Based on outcomes of the concept studies, a Dyson spectrometer design was selected as the imaging spectrometer due to its compactness, high optical output and low distortion. This paper briefly describes the options of imaging spectrometers proposed in the HALO study. Then the requirements of the advanced miniaturized imaging spectrometer system are provided. Finally the preliminary results of the development of the Dyson imaging spectrometer system will be reported.

Design and technical demonstration of a spectral dispersive module for an IR hyperspectral instrument for Earth monitoring from geo-synchronous Earth orbit

This paper presents the development of an instrumental prototype for IR hyperspectral imaging from geo-synchronous earth orbit (GEO). Within the framework of collaboration and funding support from the Canadian Space Agency (CSA), Telops performed the development and technical demonstration of a spectral dispersive module (SDM) with potential application for the US NOAA Hyperspectral Environmental Suite (HES). HES development will provide infrared and visible environmental data collection capabilities for the next GOES program series of geo-synchronous satellites that will collect weather and environmental data to aid in the prediction of weather and in climate monitoring. The design of the SDM is based on an Offner configuration. Such a design allows the gathering of high spatial and spectral resolution data while keeping the spatial and spectral distortions smaller than the size of a pixel. A convex diffraction grating is used in the system as a spectrally dispersing element. The targeted application of this Offner spectrometer configuration is weather sounding in the mid-IR spectral range. The design and demonstration phase of the SDM is described. Test results, such as spectral/spatial resolution, distortion, transmission and efficiency, with the engineering laboratory model are presented.

Thermal holographic gratings in liquid crystal cell for dynamic beam control in 1500 nm range

The study of thermally induced holographic gratings written in NLC by the laser beams at telecommunication wavelength of 1500 nm is presented. Thermally induced gratings are especially interesting as having at least one order of magnitude faster response time than orientational gratings. However, their formation in the range 1300-1600 nm is limited due to small absorption of NLCs and absence of effective doping. The formation of thermal grating in our cell is initiated by absorption in the cell walls coating. The tuning of liquid crystal temperature and orientational enhancement of thermal grating allowed us to reach 3% level of diffraction efficiency at low writing beams intensity (23 Wcm-2) and small thickness of material (0.02 mm). Holographic liquid crystal devices can be used in all-optical switching, beam routing, automatic wave front correction, phase conjugation etc.

Optical Testing and Verification Methods for the James Webb Space Telescope Integrated Science Instrument Module Element

NASA’s James Webb Space Telescope (JWST) is a 6.5m diameter, segmented, deployable telescope for cryogenic IR space astronomy. The JWST Observatory includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM), that contains four science instruments (SI) and the Fine Guidance Sensor (FGS). The SIs are mounted to a composite metering structure. The SIs and FGS were integrated to the ISIM structure and optically tested at NASAs Goddard Space Flight Center using the Optical Telescope Element SIMulator (OSIM). OSIM is a full-field, cryogenic JWST telescope simulator. SI performance, including alignment and wavefront error, was evaluated using OSIM. We describe test and analysis methods for optical performance verification of the ISIM Element, with an emphasis on the processes used to plan and execute the test. The complexity of ISIM and OSIM drove us to develop a software tool for test planning that allows for configuration control of observations, implementation of associated scripts, and management of hardware and software limits and constraints, as well as tools for rapid data evaluation, and flexible re-planning in response to the unexpected. As examples of our test and analysis approach, we discuss how factors such as the ground test thermal environment are compensated in alignment. We describe how these innovative methods for test planning and execution and post-test analysis were instrumental in the verification program for the ISIM element, with enough information to allow the reader to consider these innovations and lessons learned in this successful effort in their future testing for other programs.

JWST science instrument pupil alignment measurements

NASA’s James Webb Space Telescope (JWST) is a 6.5m diameter, segmented, deployable telescope for cryogenic IR space astronomy (~40K). The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI), including a guider. OSIM is a full field, cryogenic, optical simulator of the JWST OTE. It is the “Master Tool” for verifying the cryogenic alignment and optical performance of ISIM by providing simulated point source/star images to each of the four Science Instruments in ISIM. Included in OSIM is a Pupil Imaging Module (PIM) - a large format CCD used for measuring pupil alignment. Located at a virtual stop location within OSIM, the PIM records superimposed shadow images of pupil alignment reference (PAR) targets located in the OSIM and SI pupils. The OSIM Pupil Imaging Module was described by Brent Bos, et al, at SPIE in 2011 prior to ISIM testing. We have recently completed the third and final ISIM cryogenic performance verification test before ISIM was integrated with the OTE. In this paper, we describe PIM implementation, performance, and measurement results.

Diamond machining of ZnSe grisms for the Near Infrared Imager and Slitless Spectrograph (NIRISS) onboard JWST

LLNL diamond machined a ZnSe grism for spectroscopy of transiting exoplanets on NIRISS, a Canadian instrument that will fly on the James Webb Space Telescope. The grism operates over the wavelength range of 0.6 to 2.5 μm. It is cross-dispersed by a ZnS prism and has a resolving power in first order of ~700. The surface error over the full 29 x 30 mm grating aperture is 0.03 wave rms at 633nm. We measured a diffraction efficiency at 633 nm of 56% (nearly 88% after accounting for Fresnel reflection). The diffraction pattern is clean with no discernible ghosts.