Engineering topics
Mouroulis, Pantazis
Publications and source records attributed to Mouroulis, Pantazis.
Imaging spectrometer stray spectral response: in-flight characterization and correction
UNKNOWN
Radiometric and spectral stray light correction for the Portable Remote Imaging Spectrometer (PRISM) coastal ocean sensor
The airborne Portable Remote Imaging Spectrometer (PRISM) instrument is based on a fast (F/1.8) Dyson spectrometer operating at 350-1050 nm and a two-mirror telescope combined with a Teledyne HyViSI 6604A detector array. Raw PRISM data contain electronic and optical artifacts that must be removed prior to radiometric calibration. We provide an overview of the process transforming raw digital numbers to calibrated radiance values. Electronic panel artifacts are first corrected using empirical relationships developed from laboratory data. The instrument spectral response functions (SRF) are reconstructed using a measurement-based optimization technique. Removal of SRF effects from the data improves retrieval of true spectra, particularly in the typically low-signal near-ultraviolet and near-infrared regions. As a final step, radiometric calibration is performed using corrected measurements of an object of known radiance. Implementation of the complete calibration procedure maximizes data quality in preparation for subsequent processing steps, such as atmospheric removal and spectral signature classification.
Snow and Water Imaging Spectrometer (SWIS): First alignment and characterization results
The Snow and Water Imaging Spectrometer (SWIS) is a fast, high-uniformity, low-polarization sensitivity imaging spectrometer and telescope system designed for integration on a 6U CubeSat platform. Operating in the 350-1700 nm spectral region with 5.7 nm sampling, SWIS is capable of simultaneously addressing the demanding needs of coastal ocean science and snow and ice monitoring. New key technologies that facilitate the development of this instrument include a linear variable anti-reflection (LVAR) detector coating for stray light management, and a single drive on-board calibration mechanism utilizing a transmissive diffuser for solar calibration. We provide an overview of the SWIS instrument design and potential science applications and describe the instrument assembly and alignment, supported by laboratory measurements.
Radiometric and spectral stray light correction for the PRISM coastal ocean sensor
UNKNOWN
A Status of U-Class Earth Science Instruments at JPL
With advancements in CubeSat technologies and low-cost launch opportunities, CubeSats could play a role in meeting NASA’s key Earth science measurement objectives, especially in extreme weather and ecosystem processes. In this paper, we discuss the development of “science grade” hyperspectral imager, microwave spectrometer, IR sounder, and Ka-band radar instruments at JPL. They are scheduled to launch in early to late 2018 while the hyperspectral imager is being developed for airborne flights and for space in the future. The limitations in power, mass, and volume imposed by the CubeSat platform required the identification of new technologies in order to miniaturize instruments into a specific form factor. In conclusion, we will summarize strategies to implement small and low-cost instruments and suggest an architecture for enabling a constellation of U-class instruments.
Snow and Water Imaging Spectrometer (SWIS): Development of a CubeSat-Compatible Instrument
No abstract available
Snow and Water Imaging Spectrometer (SWIS): Development of a CubeSat-Compatible Instrument
The Snow and Water Imaging Spectrometer (SWIS) is a fast, high-uniformity, low-polarization sensitivity imaging spectrometer and telescope system designed for integration on a 6U CubeSat platform. Operating in the 350-1700 nm spectral region with 5.7 nm sampling, SWIS is capable of simultaneously addressing the demanding needs of coastal ocean science and snow and ice monitoring. New key technologies that facilitate the development of this instrument include a linear variable anti-reflection (LVAR) detector coating for stray light management, and a single drive on-board calibration mechanism utilizing a transmissive diffuser for solar calibration. We provide an overview of the SWIS instrument design, spacecraft configuration design, and potential science missions.
The Airborne Methane Plume Spectrometer (AMPS): Quantitative Imaging of Methane Plumes in Real Time
No abstract available
Snow and Water Imaging Spectrometer (SWIS): Optomechanical and System Design for a Cubesat-compatible Instrument
We discuss progress in the SWIS optomechanical design, thermal analysis, and mission plan. We also describe an innovative single drive on-board calibration system capable of addressing the stringent radiometric stability and knowledge these missions require.
Landsat-Swath Imaging Spectrometer Design
We describe the design of a high-throughput pushbroom imaging spectrometer and telescope system that is capable of Landsat swath and resolution while providing better than 10 nm per pixel spectral resolution. The design is based on a 3200 x 480 element x 18 μm pixel size focal plane array, two of which are utilized to cover the full swath. At an optical speed of F/1.8, the system is the fastest proposed to date to our knowledge. The utilization of only two spectrometer modules fed from the same telescope reduces system complexity while providing a solution within achievable detector technology. Predictions of complete system response are shown. Also, it is shown that detailed ghost analysis is a requirement for this type of spectrometer and forms an essential part of a complete design.
Monitoring Earth's Shortwave Reflectance: GEO Instrument Concept
In this paper we present a GEO instrument concept dedicated to monitoring the Earth's global spectral reflectance with a high revisit rate. Based on our measurement goals, the ideal instrument needs to be highly sensitive (SNR greater than 100) and to achieve global coverage with spectral sampling (less than or equal to 10nm) and spatial sampling (less than or equal to 1km) over a large bandwidth (380-2510 nm) with a revisit time (greater than or equal to greater than or equal to 3x/day) sufficient to fully measure the spectral-radiometric-spatial evolution of clouds and confounding factor during daytime. After a brief study of existing instruments and their capabilities, we choose to use a GEO constellation of up to 6 satellites as a platform for this instrument concept in order to achieve the revisit time requirement with a single launch. We derive the main parameters of the instrument and show the above requirements can be fulfilled while retaining an instrument architecture as compact as possible by controlling the telescope aperture size and using a passively cooled detector.
Interplanetary CubeSats: Opening the Solar System to a Broad Community at Lower Cost
Interplanetary CubeSats could enable small, low-cost missions beyond low Earth orbit. This class is defined by mass < ~ 10 kg, cost < $30 M, and durations up to 5 years. Over the coming decade, a stretch of each of six distinct technology areas, creating one overarching architecture, could enable comparatively low-cost Solar System exploration missions with capabilities far beyond those demonstrated in small satellites to date. The six technology areas are: (1) CubeSat electronics and subsystems extended to operate in the interplanetary environment, especially radiation and duration of operation; (2) Optical telecommunications to enable very small, low-power uplink/downlink over interplanetary distances; (3) Solar sail propulsion to enable high !V maneuvering using no propellant; (4) Navigation of the Interplanetary Superhighway to enable multiple destinations over reasonable mission durations using achievable !V; (5) Small, highly capable instrumentation enabling acquisition of high-quality scientific and exploration information; and (6) Onboard storage and processing of raw instrument data and navigation information to enable maximum utility of uplink and downlink telecom capacity, and minimal operations staffing. The NASA Innovative Advanced Concepts (NIAC) program in 2011 selected Interplanetary CubeSats for further investigation, some results of which are reported here for Phase 1.