The NASA Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission will provide nearly all-weather observations of 3-D temperature and humidity, as well as cloud ice and precipitation horizontal structure, at high temporal resolution to conduct high-value science investigations of tropical cyclones. TROPICS will provide rapid-refresh microwave measurements (median refresh rate better than 60 minutes for the baseline mission) over the tropics that can be used to observe the thermodynamics of the troposphere and precipitation structure for storm systems at the mesoscale and synoptic scale over the entire storm lifecycle. The TROPICS constellation mission comprises four 3U CubeSats (5.4 kg each) in three low-Earth orbital planes. Each CubeSat will host a high-performance radiometer to provide temperature profiles using seven channels near the 118.75 GHz oxygen absorption line, water vapor profiles using three channels near the 183 GHz water vapor absorption line, imagery in a single channel near 90 GHz for precipitation measurements (when combined with higher resolution water vapor channels), and a single channel at 205 GHz that is more sensitive to precipitation-sized ice particles. TROPICS spatial resolution and measurement sensitivity is comparable with current state-of-the-art observing platforms. Launches for the TROPICS constellation mission are expected in 2023 (the first launch of two of the original six CubeSats occurred on June 12, 2022 but did not successfully reach orbit). NASA’s Earth System Science Pathfinder (ESSP) Program Office approved the separate TROPICS Pathfinder mission, which launched on June 30, 2021, in advance of the TROPICS constellation mission as a technology demonstration and risk reduction effort. The TROPICS Pathfinder mission has provided an opportunity to checkout and optimize all mission elements prior to the primary constellation mission. This presentation will describe the on-orbit results for the successful TROPICS Pathfinder precursor mission and will highlight numerous technical innovations that have made the TROPICS mission possible and enabled new capabilities for future earth observing missions.

Large commercial of the shelf pixel arrays in current remote sensing instruments used in CubeSats make on-board processing increasingly important and enables data improvement. Therefore, we first consider the individual steps of the adapted bad pixel detection algorithm - ISMFD. In particular, we consider pixel-to-pixel variations and temporal flickering of pixels in commercial of the shelf sCMOS imaging sensors. We were able to detect an increase of bad pixels from (2.05±0.01)% to (4.1±0.1)% using real measurement images of the flying remote sensing instrument AtmoSHINE. A preliminary implemented adaptive on-board binning method was able to achieve a constant signal-to-noise-ration on an image with a dynamic light intensity. The additional consideration of bad pixels in the binning method could demonstrate the achievement of data quality of the future remote sensing instrument AtmoLITE.

This paper presents results from the NASA ESTO funded ATLIS-P Advanced Technology Demonstration (ATD). The ATLIS-P ATD designed, built and tested a laboratory prototype land imager based on a free form reflective triplet telescope and production digital focal plane assembly (FPA). Results show this prototype system meets Landsat 8 Visible through Shortwave Infrared (VSWIR) requirements with much less size and mass than current land imaging systems. NASA ESTO funded this work through grants 80NSSC18K0103 and NNX16AP64G to Raytheon Company.

The Athena/Epic sensorcraft jointly developed with NASA Langley Research Center will demonstrate a transformation in the measurement of the Fundamental Climate Data Record to understand the Earth's energy budget— a key gauge of climate health. Utilizing residual flight hardware from the Clouds and the Earth’s Radiant Energy System (CERES) instruments, NASA Langley completed the design, development and test of an aggregated sensor called Athena which will measure the Top of Atmosphere Outgoing Longwave Radiation. This architecture readily incorporates future technology advances, significantly reduces full lifecycle costs, and forms the basis of demonstrating emerging technologies for measuring the Earth’s radiation fields.

In 2023, Hydrosat will launch its VanZyl-1 land mapping mission and substantiate accurate and timely thermal infrared (TIR) data from a commercial SmallSat platform. Science and applications communities have made clear the needs and requirements for daily, field-scale land surface temperature and evapotranspiration data. Hydrosat’s eventual SmallSat constellation will significantly advance our monitoring and management capabilities for ecosystems, agriculture, and other applications. VanZyl-1 includes a primary TIR payload with a projected ground sample distance (GSD) of 70 meters, and secondary visible through near-infrared multi-spectral payload with a GSD of 30 meters. The TIR payload incorporates a modern microbolometer Focal Plane Array (FPA) with telescope, thermal control, and calibration subsystems designed for optimal performance within a total payload volume of approximately 16U. The payloads will be hosted on an “ESPA-class” SmallSat in partnership with Loft Orbital, and operated as part of a demonstration mission with up to 5-year planned lifetime.

Gravity waves play a major role in mesospheric and lower thermospheric (MLT) dynamics and global observations of gravity waves in this region are of particular interest. To this end, a limb sounding spatial heterodyne interferometer (SHI) is used to retrieve temperature profiles which can be subsequently used to determine wave parameters. It resolves rotational structures of the O₂ atmospheric A-band airglow emission in the near-infrared. It is visible during day- and night-time, allowing a continuous observation. The image is taken by a 2D detector plane of 900 × 900 pixels. The horizontal axis is a superposition of spectral and spatial information; the vertical axis corresponds to different tangent altitudes. We propose to split the interferogram into two halves and perform a retrieval on both sides separately, thus obtaining two spatial tracks of independent temperature data. This can be utilized to obtain some information on 3D propagation characteristics of gravity waves. The feasibility and subsequent concerns of the practical usage of the interferogram split will be discussed.

The Lunar Volatile and Mineralogy Mapping Orbiter (VMMO) comprises a low-cost 12U Cubesat with deployable solar arrays, X-Band/UHF communications, option of electric or chemical propulsion, the Lunar Volatiles and Mineralogy Mapper (LVMM) payload, and an optional GPS receiver technology demonstrator. LVMM facilitates three operational modes: Active mode using illumination of the lunar surface at 532nm, 1064nm, and 1560nm to enable volatiles mapping during the lunar night and within Permanently-Shadowed Regions (PSRs); Passive mode during the lunar day with spectral channels at 300nm, 532nm, 690nm, 1064nm, and 1560nm for mapping lunar surficial ilmenite (FeTiO3); and a Communications mode for an optical data downlink demonstration at 1560nm. Previous lunar missions have detected the presence of water-ice in the lunar South Pole region. However, there is considerable uncertainty with regards to its distribution within and across the lunar surface. A number of planned future missions will further map water ice deposits, but the spatial resolution of these observations is expected to be on the order of kilometres. The LVMM using single-mode fiber lasers can improve the special resolution of the mapping to 10s of metres. VMMO has completed the Phase A study with ESA. This paper discusses the baseline LVMM payload design and its dual-use applications for both the stand-off mapping of lunar volatiles and a high-speed optical data link demonstration. In particular, the supporting fiber-laser technology readiness was advanced through ground qualification.

One of the key challenges in future space explorers is the ability to carry out complex mission profiles while avoiding constant ground support until arrival at the mission target. A key point is precise self-knowledge of location and attitude. Over the last several years there have been many demonstrations of how to use visual cues to enable safe and precise execution of key mission phases, including in large-scale missions (most recently on NASA's Mars Perseverance). Nevertheless, this transition is sure to occur at a faster pace on small missions due to their comparatively low cost. We have investigated how to forego entirely ground-based navigation throughout a mission - between launch separation and target arrival. We propose to use primarily just three small optical instruments (two star trackers and one high-resolution camera), along with a high-performance processing unit, while considering complementary sensors such as IMUs and ranging instruments for critical events. We describe two different mission profiles, a lunar landing and an asteroid mission. We have calculated suitable trajectories to reach our targets, and describe appropriate image processing techniques to reach the required positioning performance. We also describe the covariance analyses that guide both trajectory correction timeline and the observation schedule. We have built prototype hardware instrument to test our progress towards achieving this goal, and have tested it under conditions representative of a real mission. Finally, we are currently qualifying cameras for In-Orbit Demonstrations in early 2023 to inform our next steps.

The NASA Earth Science Technology Office (ESTO) funded Improved Radiometric calibration of future land Imaging Systems (IRIS) Advanced Technology Development (ATD) is developing and demonstrating technology to simplify onboard calibration systems and reduce risk, cost, size, mass, and development time for next generation small satellite instruments, while meeting or exceeding current capabilities. IRIS addresses this objective in two different, but complementary ways. The first way involves designing and building an ultra-compact, full spectrum (0.4-2.3 µm and 4- 13 µm) end-to-end calibration source and testing this source with the existing NASA ESTO Advanced Technology Land Imaging Spectroradiometer-Prototype (ATLIS-P) built by Raytheon. IRIS extends ATLIS-P by reducing volume of the onboard calibration assembly by 90% relative to current flight systems using an innovative, full-spectrum Jones source. IRIS will demonstrate a functionally complete full-spectrum prototype land imager with much reduced size and mass by verifying calibration performance across the full spectral range and full imager field of view by comparison with well-understood NIST traceable full aperture laboratory sources. The second way involves in-flight absolute solar radiometric calibration of L8 and L9 OLI onboard lamp assemblies based on Raytheon’s patented Specular Array Calibration (SPARC) method. SPARC uses spherical convex mirrors to create a collection of “solar stars” with identical spectra and well-defined radiometric properties directly traceable to the exoatmospheric solar spectral constant. This IRIS-Vicarious (IRIS-V) aspect of the project involving SPARC site observations provides in-flight absolute calibration and image quality validation. IRIS-V intends to image a commercial SPARC site on Mauna Loa developed by Labsphere. NASA ESTO funded this work through grant 80NSSC20K1676 to Raytheon Company.

Modern detector manufacturing allows spectral and polarimetric filters to be directly integrated on top of separate detector pixels. This enables the creation of CubeSat-sized spectro-polarimetric instruments that are not much larger than the detector and a lens. Redundancy inherent to the observed scene, offers the opportunity for sparse sampling in the form of not scanning all filters at every location. However, when there are fewer pushbroom steps than filters, data are missing in the resulting data cube. The missing, largely redundant data can be filled in with interpolation methods, often called demosaicers. The choice of filters and their precise layout influences the performance of the instrument after the demosaicing process. In these proceedings we describe a part of a design toolbox for both the filter layout and the optimum parameters for the reconstruction to a full spectropolarimetric data cube. The design tool is based on training a (neural) network and jointly updating the values of the filters and demosaicer. We optimized a filter layout by training on spectro-polarimetric remote observations of the Earth acquired by SPEX airborne. This optimised filter layout could reconstruct a validation scene from five overlapping snapshots (pushbroom steps), which would take 109 pushbroom steps when measuring with a classical layout and no reconstruction.

VTT has previously developed Fabry-Pérot interferometer-based hyperspectral cameras which have been fixed focal length cameras. In some applications it would be beneficial to have zoom capability to first search the target and then zoom in to the target to collect the data. This paper describes hyperspectral camera design with zoom optics and first test result of the camera. Hyperspectral camera has two operation modes; wide mode and tele mode. Optics design is done so that only one lens group need to move which makes mechanics and operation of the camera simpler.

This PDF file contains the front matter associated with SPIE Proceedings Volume 12236 including the Title Page, Copyright information, Table of Contents, and Conference Committee Page.