The Wide Field Infrared Survey Telescope (WFIRST), NASA’s next decadal astrophysics observatory, will enable advances in astrophysics by providing a large-scale survey capability in infrared wavelengths. The observatory is designed to capture data that will allow astronomers to unlock the mysteries of the universe, answering high-priority scientific questions related to the evolution of the universe and the habitability of exoplanets. Using a 2.4 m (7.9 ft) primary mirror, WFIRST will capture comparable quality images to the Hubble Space Telescope, but with more than 100 times the field of view, enabling the observatory to conduct comprehensive and efficient surveys of the infrared sky. Scientists estimate WFIRST has the potential to examine a billion galaxies over the course of its mission. Ball Aerospace was selected as NASA’s partner to design and develop the Wide Field Instrument (WFI) Opto-Mechanical Assembly for the WFIRST mission. The optical-mechanical assembly, which includes the optical bench, thermal control system, precision mechanisms, optics, electronics, and the relative calibration system, provides the stable structure and thermal environment that enables the wide-field, high quality observations of WFI. Ball's innovative design uses heritage hardware to unfold the incoming light, providing cost and schedule savings to the mission. In this paper, we present an overview of the WFI design, which completed its preliminary design review in June 2019. The overview includes a discussion of the design process, including several of the trade studies completed that led to the unfolded optical path architecture for the instrument design. The current state of the design is shown.
REMI (Reduced Envelope Multispectral Imager) is a new instrument developed by Ball Aerospace specifically for the Sustained Land Imaging (SLI) program. The goal of REMI is to meet the current Landsat mission requirements with a much smaller volume, lower cost payload. A lower single unit recurring cost enables economies of scale on multiple builds by leveraging non-recurring engineering costs. This lower cost enables multiple copies on-orbit at the same time for improved temporal sampling, an innovative approach to space segment reliability, and more frequent technology onramps. REMI achieves miniaturization through use of a common aperture for all spectral bands. REMI features a pointing mechanism that compensates for platform and ground motion while using cross-track, step-stare pointing to produce contiguous ground coverage in all spectral bands. The status of the REMI development and airborne flight testing will be presented.
To consistently observe deteriorating air quality over East Asia, the National Institute of Environmental Research, Republic of Korea, is planning to launch an environmental observation sensor, the Geostationary Environment Monitoring Spectrometer (GEMS), onboard the GK-2B satellite (a successor to the GeoKOMPSAT-1) in late 2019. GEMS is a hyperspectral spectrometer that covers the ultraviolet–visible range (300 to 500 nm) with full-width at half-maximum of 0.6 nm. It has been designed for the observation of air pollutants and short-lived climate pollutants. GEMS captures images at hourly intervals in the daytime, alternating with the Geostationary Ocean Color Imager-II every 30 min. Over the Seoul Special Metropolitan area, South Korea, the spatial sampling resolution of GEMS is 3.5 × 8 km (north–south and east–west, respectively). There are 16 baseline products, including aerosol optical depth and the vertical column density of trace gases such as nitrogen dioxide, sulfur dioxide, formaldehyde, and ozone. Research continues into additional applications (e.g., ground-level concentrations and emissions).
The Geostationary Environmental Monitoring Spectrometer (GEMS) and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instruments will provide a new capability for the understanding of air quality and pollution. Ball Aerospace is the developer of these UV/Vis Hyperspectral sensors. The GEMS and TEMPO instrument use proven remote sensing techniques and take advantage of a geostationary orbit to take hourly measurements of their respective geographical areas. The high spatial and temporal resolution of these instruments will allow for measurements of the complex diurnal cycle of pollution driven by the combination of photochemistry, chemical composition and the dynamic nature of the atmosphere.
The GEMS instrument was built for the Korea Aerospace Research Institute and their customer, the National Institute of Environmental Research (NIER) and the Principle Investigator (PI) is Jhoon Kim of Yonsei University. The TEMPO instrument was built for NASA under the Earth Venture Instrument (EVI) Program. NASA Langley Research Center (LaRC) is the managing center and the PI is Kelly Chance of the Smithsonian Astrophysical Observatory (SAO).
Greatly improved understanding of areas and objects of interest can be gained when real time, full-motion Flash LiDAR is fused with inertial navigation data and multi-spectral context imagery. On its own, full-motion Flash LiDAR provides the opportunity to exploit the z dimension for improved intelligence vs. 2-D full-motion video (FMV). The intelligence value of this data is enhanced when it is combined with inertial navigation data to produce an extended, georegistered data set suitable for a variety of analysis. Further, when fused with multispectral context imagery the typical point cloud now becomes a rich 3-D scene which is intuitively obvious to the user and allows rapid cognitive analysis with little or no training. Ball Aerospace has developed and demonstrated a real-time, full-motion LIDAR system that fuses context imagery (VIS to MWIR demonstrated) and inertial navigation data in real time, and can stream these information-rich geolocated/fused 3-D scenes from an airborne platform. In addition, since the higher-resolution context camera is boresighted and frame synchronized to the LiDAR camera and the LiDAR camera is an array sensor, techniques have been developed to rapidly interpolate the LIDAR pixel values creating a point cloud that has the same resolution as the context camera, effectively creating a high definition (HD) LiDAR image. This paper presents a design overview of the Ball TotalSight™ LIDAR system along with typical results over urban and rural areas collected from both rotary and fixed-wing aircraft. We conclude with a discussion of future work.