2016 IIP Projects Awarded
17 Projects Awarded Funding Under the Instrument Incubator Program (IIP) (2016 ROSES A.42 Solicitation NNH16ZDA001N-IIP Research Opportunities in Space and Earth Sciences)
10/31/2016 – NASA’s Science Mission Directorate, NASA Headquarters, Washington, DC, has selected proposals, for the Instrument Incubator Program (IIP-16) in support of the Earth Science Division (ESD). The IIP-16 will provide instruments and instrument subsystems technology developments that will enable future Earth science measurements and visionary Earth-observing concepts.
The ESD is awarding 17 proposals, for a total dollar value over a three-year period of approximately $53 million, through the Earth Science Technology Office (ESTO).
The goals of the IIP are to research, develop, and demonstrate new measurement technologies that:
- Enable new or greatly enhance Earth observation measurements and
- Reduce the risk, cost, size, volume, mass, and development time of Earth observing instruments.
The IIP is designed to reduce the risk of new innovative instrument systems so that they can be successfully accepted by future science solicitations. The program is designed to be flexible enough to accept technology developments at various stages of maturity, and through appropriate risk reduction activities (such as instrument design, laboratory breadboards, engineering models, laboratory and/or field demonstrations) advance the technology readiness of the instrument or instrument subsystem for infusion into future NASA science missions.
Eighty IIP-16 proposals were evaluated of which 17 have been selected for award. The awards are as follows (names hyperlinked to project abstracts):
| Scott Bailey, Virginia Tech A Solar Occultation Instrument Suitable for Constellations of Small Satellites |
| Robert Damadeo, Langley Research Center Stratospheric Aerosol and Gas Experiment (SAGE) IV Pathfinder |
| Roger De Roo, University of Michigan Wideband Autocorrelation Radiometer Receiver Development and Demonstration for Direct Measurement of Terrestrial Snow and Ice Accumulation |
| Matthew DeLand, Science Systems and Applications, Inc. Advanced Development of a Multi-Angle Stratospheric Aerosol Radiometer (MASTAR) |
| Philip Ely, DRS Technologies Multi-Band Radiometric Imager Utilizing Uncooled Microbolometer Arrays with Piezo Backscan for Earth Observation Mission Applications |
| Michael Kelly, Johns Hopkins University Applied Physics Lab Compact Midwave Imaging System |
| Matthew Lebsock, Jet Propulsion Laboratory Development and Demonstration of an Airborne Differential Absorption Radar for Humidity Sounding Inside Clouds |
| Nathaniel Livesey, Jet PropulsionLaboratory Stratospheric Water Inventory, Tomography of Convective Hydration (SWITCH) |
| Ronald Lockwood, MIT Lincoln Laboratory Chrisp Compact VNIR/SWIR Imaging Spectrometer Development |
| Charles Miller, Jet Propulsion Laboratory CARBO: The Carbon Balance Observatory |
| David Munton, University of Texas, Austin An Instrument Concept for Combined Observations of GNSS and Astronomical Sources Through a Standard Signal Path for Geodetic Applications |
| Jon Ranson, Goddard Space Flight Center Miniaturized Imaging Spectrometer to Measure Vegetation Structure and Function – MiniSpec |
| Chris Ruf, University of Michigan Next Generation GNSS Bistatic Radar Receiver |
| Mauricio Sanchez-Barbetty, Jet Propulsion Laboratory Multi Application Smallsat Tri-Band Radar |
| Tomasz Tkaczyk, Rice University Tunable Light-Guide Image Processing Snapshot Spectrometer (TuLIPSS) for Earth Science Research and Observation |
| Dong Wu, Goddard Space Flight Center SWIRP: Compact Submm-Wave and LWIR Polarimeters for Cirrus Ice Properties |
| Lauren Wye, SRI International SRI CubeSat Imaging Radar for Earth Science: Instrument Development and Demonstration (CIRES-IDD) |
Scott Bailey, Virginia Tech
A Solar Occultation Instrument Suitable for Constellations of Small Satellites
GLO: A Solar Occultation Instrument Suitable for Constellations of Small Satellites
A key challenge in the Earth Science community is to exploit rapidly advancing microsatellite (microsat) technology in the task of providing the myriad of global measurements required to understand key processes. Microsats offer the possibility of inexpensive access to space, but also present payload design challenges resulting from issues such as limited size, weight, and power (SWaP) capacity and pointing capability. We propose a technology demonstration of an instrument we refer to as GLO (GFCR (Gas Filter Correlation Radiometry) Limb solar Occultation) which would measure the vertical profile of atmospheric trace species, with state-of-the-art accuracy. GLO contains 23 Visible Near Infrared (VNIR) and Short Wavelength Infrared (SWIR) spectral bands and measures 10 constituents plus temperature (T), yet fits into a 29x16x16 cm form factor, weighs 5.25 kg, consumes just 28.2 W during observations, and does not levy stringent pointing requirements to the spacecraft. GLO has heritage from HALOE and AIM/SOFIE, both highly successful solar occultation (SO) instruments, but (using recent advances in focal plane array (FPA), and cooler technology) is much smaller and requires substantially less power. In addition, it has significantly improved vertical resolution, pointing, and Upper Troposphere and Lower Stratosphere (UTLS) aerosol and T measurement capability, as well as much reduced sensitivity to aerosol contamination in trace gas retrievals. Novel aspects of the GLO sensor include: use of tactical, but space qualified, imaging FPAs (low cost); GFCR with imaging arrays (precise channel coalignment and registration); proxy GFCR for UTLS H2O and O3 (increased insensitivity to aerosol contamination in the UTLS); and VNR plus SWIR aerosol extinction measurement capability (aerosol extinction plus bulk properties).
While GLO could have many applications (including, e.g., an inexpensive stratospheric monitoring sensor), we conceived it to probe a key but poorly documented component of the climate system, the UTLS, in a mission concept referred to as SOCRATES (Solar Occultation Constellation for Retrieving Aerosols and Trace Element Species). The goal of SOCRATES is to quantify the role of the UTLS in climate change. For SOCRATES, GLO measures T, radiatively active gases (H2O, O3, CH4, N2O), aerosols, and transport tracers (HDO, CO, HCN, HF, HCl) with vertical resolution (<1 km) and geographic sampling required for UTLS radiative forcing calculations.
Satellite SO instruments provide high vertical resolution and precision, but sample only 2 latitudes per orbit. To mitigate this shortcoming, SOCRATES consists of a constellation of 6 GLO sensors, deployed from a single launch vehicle into orbits with slightly different mean altitudes. The dispersing orbits provide the required spatial and temporal sampling, with coverage from 65 latitude. We have shown that the SOCRATES GLO constellation (6 sensors & microsats) meets all measurement complement, accuracy, vertical resolution, and spatial sampling requirements, and can be fabricated, launched, and operated in a 26-month mission within the NASA Earth Venture Mission cost capped budget.
Under this proposal, we will refine the design and fabricate a complete prototype GLO sensor [identical in form, fit and function to the SOCRATES/GLO sensor except for the use of non-space qualified (but functionally identical) components], perform functional and environmental tests to confirm it can meet SOCRATES measurement requirements, and validate the instrument concept through ground and balloon-based observations. This will provide a nearly complete demonstration of the GLO technology, and measurement approach and capabilities. The goal is to raise the GLO sensor technique and design from TRL 4 to TRL 6, providing risk reduction for the SOCRATES mission concept, and for the use of GLO in other missions.
Robert Damadeo, Langley Research Center
Stratospheric Aerosol and Gas Experiment (SAGE) IV Pathfinder
We propose to develop and build a Stratospheric Aerosol and Gas Experiment (SAGE) IV Pathfinder measurement system to demonstrate a new imaging solar occultation technique that enables a sustainable solution to NASA’s mandate under the Clean Air Act to monitor stratospheric ozone and to extend the SAGE record of stratospheric aerosol optical depth, a critical component of climate change. Leveraging over 40 years of solar occultation experience at NASA Langley Research Center (LaRC), our innovative approach will make high-precision, SAGE-quality measurements that are insensitive to pointing uncertainties of previous occultation instruments at a significant cost reduction by targeting development for an inexpensive 6U CubeSat sensorcraft rather than a traditional full-sized instrument and spacecraft bus mission. SAGE IV’s reduced form factor configuration uses existing commercially available hardware assembled in a novel configuration leading to a significant reduction in cost. Furthermore, our SAGE IV sensorcraft concept, when operating as a constellation, provides enhanced geographic coverage and redundancy.
The objective of our investigation is to develop, demonstrate, and validate a laboratory SAGE IV prototype through the IIP work proposed herein, enabling a follow-on transition to a low-risk flight mission. Under the IIP, our expert team, leveraging existing work performed under NASA LaRC Internal Research and Development (IRAD) funding, will (1) finalize the SAGE IV laboratory instrument design, (2) assemble the SAGE IV laboratory prototype, and (3) demonstrate the ability of the SAGE IV system to produce high-precision radiometric measurements via laboratory characterization and direct sun-viewing testing. SAGE IV will observe and image the Sun as a radiometric source in various spectral channels between 370 nm and 1050 nm. Our team will utilize proto-flight design techniques to the extent possible and will implement interfaces for a preselected small satellite bus to position the IIP development for a later flight opportunity.
Our proposed development will address the technical challenges of obtaining and characterizing a commercially available flight candidate detector; controlling stray light within our novel, small telescope design; characterization of the integrated optical system; implementation of embedded control functions using a Xilinx System on Chip, and end-to-end system characterization/validation including new pointing algorithms necessary for sensorcraft operation. By successfully completing the proposed development work, our team will advance the technology readiness level (TRL) of essential instrument systems from TRL 3 to TRL 5 over 3 years. This IIP will advance the state of the art and pave the way for a future constellation of sensorcraft capable of affordably meeting NASA’s objective to preserve the continuity of the stratospheric ozone and aerosol data records.
Roger De Roo, University of Michigan
Wideband Autocorrelation Radiometer Receiver Development and Demonstration for Direct Measurement of Terrestrial Snow and Ice Accumulation
The seasonal terrestrial snow pack is an important source of water for many parts of the globe. Snow’s high albedo, relative to the terrain in the absence of snow, is an important driver of Earth’s energy balance, and long term changes to the statistics of the snow pack’s properties are both a consequence and a cause of climate change. The global quantification of the amount of water in the snow pack reservoir is a long term objective of NASA’s Earth Science Division.
Thus far, the primary means of quantifying the amount of snow on the ground has been via the differential scatter-darkening mechanism, such as the 19 and 37 GHz brightness difference. While a 35+ year time series of passive microwave satellite data has been made, progress in understanding the scatter-darkened brightness signature of snow continues, especially for forested areas where vegetation scattering confounds the signature.
This proposal looks to advance an alternative approach to using passive microwave to measure the snow accumulation. Wideband autocorrelation radiometry (WiBAR) is a technique wherein the electromagnetic propagation time across a layered media, such as snow pack or lake ice, can be remotely sensed. Thermal emission from the ground under the snow pack propagates up through the snow pack to the receiver. When the upper and lower surfaces of the snow pack are locally smooth, which is true at sufficiently long wavelengths, additional paths result from the reflection of the upward traveling wave from first the upper and then the lower surface of the snow pack. Arriving at the antenna, these waves are identical except for their amplitude and the time lag associated with the extra transit of the snow pack. This time lag is the observable.
For sufficiently long wavelengths, the snow snow grains that cause the scattering are sufficiently deep in the Rayleigh region so as to be of minor importance. Unlike scatter darkening, where the microscopic properties of snow dominate the signal and the desired macroscopic properties are secondary, for WiBAR, the macroscopic properties of the snow depth is the most important parameter determining the signal, modified by the density (and thus it measures SWE), and the microscopic properties, responsible for the scattering, reduce the signal strength but do not alter the quantification of the accumulation. The bandwidth of the radiometer determines the minimum vertical extent that is observable. A wide bandwidth (several gigahertz) is desired for the relatively shallow snow covers encountered on Earth.
We have demonstrated that this signal exists and can be observed both for a snow pack and for a fresh-water lake ice pack with ground-based observations. We have done this with a spectrum analyzer functioning as the radiometer receiver back-end: in the frequency domain, the delayed ray interferes with the direct ray to produce constructive maxima and destructive minima in the brightness spectra. But this technique is inherently slow, as the number of samples required is high and the instantaneous bandwidth is low. This frequency-domain approach is much too slow for spaceborne or even airborne observation. These observations also confirm the robustness of the approach to radio-frequency interference (RFI): since the observable is a time-delay and not a brightness magnitude, the narrow-band RFI does not mask the broadband WiBAR signature.
We propose to develop a radiometer back-end that observes the entire spectrum of interest simultaneously, which will greatly reduce the observation time, possibly down to the order of milliseconds, which would make observations from a moving platform possible. We will then demonstrate the technological advancement in a direct comparison to the spectrum analyzer-based receiver measurement in a laboratory setting.
Matthew DeLand, Science Systems and Applications, Inc.
Advanced Development of a Multi-Angle Stratospheric Aerosol Radiometer (MASTAR)
The contribution of atmospheric aerosols to the Earth’s energy budget is an important, yet relatively uncertain, component of the Earth system. Stratospheric aerosols represent a less well-studied, but nevertheless significant, element of this contribution through their impact on direct radiative forcing of the climate system.
Comprehensive measurements of aerosol extinction vertical profiles with dense spatial sampling are needed to better constrain climate model simulations of aerosol extinction, composition, and particle size, in order to compute climate impacts. The most effective source of stratospheric aerosol extinction data comes from satellite limb scattering measurements, which provide greater sensitivity than space-based lidar and much better spatial sampling than occultation measurements. The Ozone Mapping and Profiling Suite (OMPS) Limb Profiler (LP), currently flying on the Suomi National Polar-orbiting Partnership (S-NPP) satellite, has been providing daily aerosol extinction profile data from limb scattering measurements since April 2012. While the S-NPP OMPS LP instrument was designed for a 7-year operating lifetime, the next OMPS LP instrument is not scheduled to fly until 2022. This raises the possibility of a data gap in this crucial measurement.
We have developed a prototype instrument, called Global Aerosol Monitoring System (GAMS), to supplement the OMPS LP measurements. Our design uses multiple viewing directions to improve spatial sampling and provide more balanced measurement sensitivity throughout the orbit compared to OMPS LP. Wavelength selection in this design is limited to simple filters (675 nm for aerosol science, 350 nm for altitude registration) to enable a compact instrument suitable for Cubesat deployment. This prototype instrument has been developed with NASA GSFC internal funding, and currently meets TRL 2 criteria.
This proposal to the Instrument/Measurement Concept Demonstration subelement of the Instrument Incubator Program (IIP-ICD) describes our plans to improve the GAMS design to produce a more scientifically capable and flight-ready instrument (Multi-Angle STratospheric Radiometer, MASTAR). The MASTAR concept was formally submitted to the 2017 Decadal Survey for Earth Science second request for information in May 2016. Adding a second channel at 1020 nm for science measurements will improve aerosol detection capabilities at low altitudes, help determine aerosol particle size properties, and increase continuity with heritage data sets. Optical design studies will be performed to optimize the performance of MASTAR and quantify stray light behavior. We will also assess the potential benefits of incorporating onboard data processing capabilities to satisfy the science objectives. The goal of this effort is to have a laboratory tested MASTAR instrument at TRL 4 by the end of the IIP award period. We do not include a Data Management Plan in this proposal, following guidance provided at the NSPIRES web site.
Philip Ely, DRS Technologies
Multi-Band Radiometric Imager Utilizing Uncooled Microbolometer Arrays with Piezo Backscan for Earth Observation Mission Applications
DRS Technologies takes pleasure in presenting this Multi-Band Uncooled Radiometer Imager (MURI) proposal for the Instrument Incubator Program (IIP) that will provide improved radiometric imaging performance, substantially reduce the cost, complexity, and development time for future Polar Orbiting earth observation imaging radiometer sensors. Our proposed solution leverages conventional, low cost uncooled microbolometers with a compact piezo driven backscan and our patented TCOMP algorithms for improved radiometric accuracy and stability. Our solution eliminates the need for cryogenic cooling, solves the problem of image smear associated with the bolometers relatively long time constant, while simultaneously ensuring low NEDT.
The objective of the DRS proposed MURI program is to demonstrate that modern, low cost, large area microbolometer FPAs can be utilized to provide narrow band radiometrically accurate imaging in 8 LWIR bands for Earth Science applications. The potential earth science applications for this technology are Land Surface Climatology, measurement of soil moisture content, measurement of Ecosystem Dynamics, Volcano Monitoring, Hazard monitoring, Geology and Soils. On the IIP Program, DRS plans to design, build, test and demonstrate an uncooled microbolometer breadboard sensor hardware for earth observation. Our Science partner, Rochester Institute of Technology (RIT), will support the airborne data collects, radiometric data analysis and comparison to LANDSAT 8 for a truth reference and the science implementation aspect of the instrument data collects. DRS/RIT will collect airborne data for three primary applications in 8 spectral bands. The first will assess initial data quality and calibration with known targets deployed, the second will demonstrate scientific products available over vegetative and urban environments, while the third will demonstrate important aspects of volcano monitoring. One key technological solution is the use of a piezo back-scan stage located at the image plane. The piezo drive velocity will be set to match the aircraft ground velocity during image collection, such that the image smear from the bolometer’s long time constant is eliminated. This is critical for the use of a standard microbolometer array which typically has ~14msec time constant. Another key feature is the real-time radiometric correction that will occur during flight to account for the instrument and optics temperature changes during operation. This methodology is being utilized by DRS in commercial radiometers and will be implemented here to account for instrument/optics temperature changes and their contribution to radiometric error. This is a dramatic shift from prior radiometers built for earth observation in that those instruments typically cool the optics to reduce radiometric error.
We envision a space instrument using 10 FPAs, with up to 12 spectral filters to cover a ground swath width of 310km from a 705km altitude orbit and a 100m GSD. For this airborne demo we plan to utilize 4 FPAs with 8 spectral band filters to demonstrate the key technology within the more limited IIP program budget. For an airborne demo, using 120mm EFL f/1 optics at 15,000ft altitude, will have a 0.65m GSD with two parallel swath widths of 414km separated by a gap of 619m. We will show direct applicability to a space instrument and how it is easily scalable using a stagger butted array approach. Much of the same hardware could be utilized on a space version of this instrument.
Period of performance of this IIP project is expected to be 36 months. The first year of the program will involve the design of the instrument hardware, the second year will be the build of the components integration and assembly of the instrument and the third year will be laboratory test of the instrument and airborne field testing. Entry level TRL for this instrument is 3; exit level TRL at the end of year 3 will be 6.
Michael Kelly, Johns Hopkins University Applied Physics Lab
Compact Midwave Imaging System
We propose to develop a next-generation satellite instrument called the Compact Midwave Imaging Sensor (CMIS), which avoids the need for large, expensive cryogenic cooling and thus permits deployment on small satellites for multiple mission applications including imaging of cloud properties, brightness temperature, cloud optical depth, and cloud fraction as well as characterizing mid-IR thermal emission from forest fires and volcanic eruptions. In this development effort, we focus on the application for measuring cloud properties. Long-term measurements of the global distribution of clouds are needed to provide inputs to climatological models for global change studies. Instruments that rely on the atmospheric window in the midwave infrared (MWIR; 3-5 μm) offer utility not only for cloud remote sensing, but also for cloud-snow discrimination. Until recently, only cryogenically cooled detector technologies such as InSb and HgCdTe were available for MWIR sensing. Because of the reliance of these technologies on closed-cycle coolers, heritage MWIR sensors tend to fly on large spacecraft due to their large size, weight, and power (SWaP). The Johns Hopkins University Applied Physics Laboratory (APL) proposes an Instrument Development and Demonstration (IIP-IDD) project to increase the technical readiness of CMIS. The low-cost, small-SWaP CMIS solution is based on the use of thermoelectrically cooled sensor that leverages newly available, low noise lead salt (PbSe) array detector technology. Lab measurements have demonstrated NEdT = 0.03K for the optimum detector operating temperature of 230 K. The objective of the proposed project is to design and develop a spaceflight prototype unit, test, characterize and calibrate the unit, and conduct an airborne campaign to demonstrate its capabilities.
Matthew Lebsock, Jet Propulsion Laboratory
Development and Demonstration of an Airborne Differential Absorption Radar for Humidity Sounding Inside Clouds
We will develop an airborne differential absorption radar, dubbed VIPR (Vapor/Ice Profiling Radar), to demonstrate a new measurement capability of simultaneously measuring water vapor and ice content inside clouds with high precision and spatial resolution. The measurements fill a gap in the existing observing system, which struggles to profile water vapor within clouds. VIPRs observations address key unsolved science questions regarding the processes regulating cloud lifecycle and the transport of water vapor by convection. The new observations will cut across several of the Earth Science focus areas including Weather, Climate Variability and Change, and Water and Energy Cycle. The concept has an entry level TRL of 3, which we will raise to TRL 6 over a three-year effort.
First, we will design and build a frequency-tunable 183 GHz radar instrument. VIPR will utilize an all-solid-state transceiver based on state-of-the-art semiconductor amplifier and frequency-multiplier/mixer technology to achieve a transmit power approaching 1 W and a receiver noise figure better than 8 dB. A frequency-modulated continuous-wave (FMCW) radar mode will be used with high isolation quasi-optical duplexing to optimize detection sensitivity. The operating frequency will be tunable over 10 GHz to span a large dynamic range of water vapor attenuation near the 183 GHz atmospheric absorption line, and a 25-cm scale monostatic reflector antenna will provide sufficient gain for airborne measurements above upper tropospheric ice clouds.
Second, we will demonstrate of the measurement technique from an airborne platform. We will install VIPR in an unpressurized aircraft and acquire water vapor and cloud observations in the world’s first demonstration of a cloud-profiling differential absorption radar. Retrievals that convert the differential scatterometry into water vapor profiles will be adapted from our existing algorithms based on CloudSat and the Microwave Limb Sounder. Measurement validation will be performed against in-situ water vapor measurements from coincident radiosondes.
Nathaniel Livesey, Jet PropulsionLaboratory
Stratospheric Water Inventory, Tomography of Convective Hydration (SWITCH)
We propose to develop and test the key transmitter and receiver systems for a spaceborne active microwave occultation sounder system making two-dimensional tomographic atmospheric composition observations with unprecedented spatial resolution (~500m vertical, 10km along track). The measurement approach employs multiple small (e.g., 6U- CubeSat-class) transmitters orbiting in the same plane and flight direction as a separate (larger) receiver instrument. The transmitters emit continuous distinct tones, and the receiver observes all transmitters simultaneously and continuously, in an occultation viewing geometry. The vertical resolution of the measurements is set, to first order, by the along-orbit spacing of the transmitters, with the horizontal resolution set by signal to noise and radiative transfer considerations.
We will develop the transmitter and receiver elements for such a system operating in the 183-GHz region, incorporating state-of-the-art technologies. The specific science target for this measurement system relates to the impact of small-scale processes (notably overshooting deep convection) on lower stratospheric (~1520km) water vapor, and hence, given water vapors role as a greenhouse gas, on climate. Straightforward retuning of the transmitters and receiver (including, potentially, in orbit) enables high resolution measurements of other species, notably ozone, for which other small scale processes (e.g., those driving exchange of air between the stratosphere and troposphere) play important roles in the Earth system.
The transmitters will use a CMOS-based ASIC to generate tones in the 1011GHz range that will then be up-converted to 183 “184GHz using a heterodyne mixer driven by a low-power local oscillator ASIC. The receiver will use a MMIC LNA-based front end subsystem developed under the ACT program, in combination with a new FPGA-based digital spectrometer. In addition to being suitable for stand-alone flight, the receiver could be incorporated as an additional channel on a future passive microwave limb sounding instrument, such as that being developed to continue and augment the record from the Aura Microwave Limb Sounder.
The components used for the transmitters and receiver are currently at TRL-4 or higher. We will design, fabricate and test the transmitter and receiver subsystems and systems, and validate them in laboratory and ground-to-ground configurations. Air-to-air testing will also be performed using a pair of high-altitude balloons, establishing TRL-6 for the measurement approach and its proposed implementation.
Ronald Lockwood, MIT Lincoln Laboratory
Chrisp Compact VNIR/SWIR Imaging Spectrometer Development
This proposal addresses the development of a compact, but highly performing, imaging spectrometer for space-based missions in the solar reflective spectral range. An initial design shows great promise but requires demonstration, particularly in the areas of micro-lithographic optical elements and for stray light control. We propose a design with a minimum of 1500 spatial samples with 200 spectral bands over the 400 nm to 2400 nm range. The imaging spectrometer volume is approximately 7.6 cm x 7 cm x 5.4 cm prior to packaging. The design is highly performing in both aberration control and in signal-to-noise performance. The purpose of this proposal is to develop a breadboard spectrometer that utilizes a catadioptric lens and a dual-faceted immersion grating. The later is a significant simplification when compared to the current standard forms, such as the Dyson or Offner forms, that require powered gratings. The breadboard will demonstrate the design and enable a quantitative assessment of the performance and of stray light contamination. This last is critical if an imaging spectrometer is to meet the stringent scientific requirements necessary for the climate change mission. The small size will also facilitate the temperature control of the spectral imager for long-term calibration stability. The design is suitable for both a small satellite platform or an unmanned aerial vehicle of modest size. The design represents a considerable reduction in size and mass compared to current designs and it is expected to also reduce risk due to its simplicity.
Charles Miller, Jet Propulsion Laboratory
CARBO: The Carbon Balance Observatory
Scientific consensus from a 2015 pre-Decadal Survey workshop highlighted the essential need for a wide-swath (mapping) low earth orbit (LEO) instrument delivering carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) measurements with global coverage. OCO-2 pioneered space-based CO2 remote sensing, but lacks the CH4, CO and mapping capabilities required for an improved understanding of the global carbon cycle.
The Carbon Balance Observatory (CARBO) advances key technologies to enable high-performance, cost-effective solutions for a space-based carbon-climate observing system. CARBO is a compact, modular, 15-30 field of view spectrometer that delivers high-precision CO2, CH4, CO and solar induced chlorophyll fluorescence (SIF) data with weekly global coverage from LEO.
CARBO employs innovative immersion grating technologies to achieve diffraction-limited performance with OCO-like spatial (2×2 km2) and spectral (20,000) resolution in a package that is >50% smaller, lighter and more cost-effective. CARBO delivers a 25- to 50-fold increase in spatial coverage compared to OCO-2 with no loss of detection sensitivity. Individual CARBO modules weigh < 20 kg, opening diverse new platform opportunities.
We will design CARBO modules covering 4 different spectral ranges then build and field test a 2-channel CO2/CH4 and SIF system. This will validate CARBO technology and deliver an instrument that can be adapted for airborne deployment and satellite validation (e.g. OCO-2, OCO-3, TropOMI).
Our implementation develops and demonstrates CARBO measurement technologies:
(1) Fabricate immersion gratings using e-beam lithography
(2) Design and fabricate individual spectrometer/telescope modules in identical housings
(3) Integrate two spectrometer/telescope modules into a single system
(4) Field-test the integrated system on Mt Wilson, validating alignment, SNR and CO2, CH4 and SIF measurement precision.
The CARBO system has entry TRL3. Tasks 1-2 advance CARBO’s modular architecture to TRL4. Tasks 3-4 advance the system to exit TRL6. The period of performance is 3 years with a start in CY2017.
David Munton, University of Texas, Austin
An Instrument Concept for Combined Observations of GNSS and Astronomical Sources Through a Standard Signal Path for Geodetic Applications
The stability of the terrestrial reference frame is critical for future scientific needs and both Global Navigation Satellite Systems (GNSS) and Very Long Baseline interferometry (VLBI) instruments are crucial for defining the terrestrial reference frame. Yet currently, VLBI and GNSS instrumentation operate independently, with each instrument subject to unique biases and calibration requirements. To relate these measurements requires a physical measurement of the separation vector between the phase center of the VLBI dish and the phase center of the GNSS antenna, or some proxy.
We ask the following question: “Is it possible to develop an instrument concept in which GNSS signals and astronomical source signals are sampled via the same signal chain, effectively ensuring that both measurements are made from the same antenna phase center, when processed in conjunction with measurements from a VLBI-like antenna?”
In our vision a calibrated wide-bandwidth instrument that is capable of capturing GNSS and VLBI signals of interest simultaneously, allows us to have both signals seen through a combined and unified instrument. This tight coupling of these two measurements eliminates the need for additional physical ties between instruments. Ultimately, we expect this work to contribute to improvements in the accuracy and stability of geodetic reference frames. A wide variety of earth observations, particularly those measuring earth features like sea level from airborne and space-borne platforms will benefit from these improvements. As a first step towards this larger vision, we propose for this initial incubator effort a UT1 measurement, which directly relates to a wide variety of mass transport phenomena in the earth system. As a first step towards this larger vision, we intend an instrument concept development effort which would investigate the development of a combined instrument while focusing on a straightforward goal of geodetic interest. We intend to focus on the measurement of UT1 using a VLBI dish and two low gain antennas. UT1, which is UT0 corrected for polar wander, is a routinely observed quantity so truth data will be available. Our plan is to demonstrate our concept using a VLBI dish, along with two small-aperture GNSS-like antennas together. We will utilize a High Rate Tracking Receiver (HRTR) we have developed as a data collection instrument. We have aligned our plan with scheduled installation of a NASA Space Geodesy Project VLBI antenna at McDonald Observatory in late 2017. This would serve as the source of our VLBI measurements, but a substantial fraction of the work will be done using a 3-m dish antenna at Applied Research Laboratories, The University of Texas at Austin (ARL:UT.) This effort is envisioned as an 18-month effort, beginning 1 January 2017 and completing 30 June 2018, with a go/no go decision point at month 12 on whether to perform the full tests with a VLBI antenna. In the first 12 months, we will primarily focus on the high-level processing architecture, explicitly defining how UT1 will be computed from measurements, as well as implementation of this architecture, and initial tests using a 3m dish and an existing HRTR available at ARL:UT. This effort will begin with a TRL level of 2, and the exit TRL level will be 3.
Jon Ranson, Goddard Space Flight Center
Miniaturized Imaging Spectrometer to Measure Vegetation Structure and Function – MiniSpec
Earth’s vegetated ecosystems are a key factor for sustaining life on Earth. They provide food, fiber and habitat and operate as key components of the carbon, water and energy cycles. They also offer the benefit of functioning to removing CO2 from the atmosphere and converting it to stored biomass ( and oxygen) but are susceptible to changing climate.
NASA has strong interest in detecting and predicting changes to Earth’s ecosystems as described in their Strategic and Science plans. Vegetation productivity can be estimated by light use efficiency (LUE) models which take into account vegetation stress from lack of soil moisture, disease and insects etc.. Variable shadow fraction, however, limits the accuracy of this approach and currently used methods and concepts require complex sensors with multi-angle views to infer shadow fraction. The instrument concept proposed here is designed to provide the spectral radiance measurements needed for vegetation functioning and high definition vegetation structure diurnal sampling . The scientific measurements needed are visible, near infrared and shortwave infrared calibrated radiances for vegetation function, high definition, ~1 meter resolution panchromatic stereo images for vegetation structure. These measurements are to acquired at three times per day best suited to capture vegetation functional response to environmental conditions. requires a diurnal constellation to capture data at appropriate times during the daylight hours. The most robust and cost effective approach is to deploy six SmallSats on an EELV Secondary Payload (ESPA) ring. This requires that the spectrometer be miniaturized yet fully capable of delivering the spectral and spatial measurements. The proposal team will utilize free form optics enabling high spectral and spatial resolution on a very small bus. For the first time the complete picture of vegetation functioning will be acquired and type, amount and productivity of vegetation will be quantified. (a)
Objectives and Benefits
The goal of this work is to develop a viable instrument concept using innovative free-form optics suitable for diurnal ( i.e., day time multi-temporal) observations of vegetation type, structure and productivity to be deployed on a small satellite constellation.
Objectives are:
1) develop and test an instrument concept that uses free form optics and other technologies to reduce size and mass of a hyperspectral spectrometer to acquire reflected solar radiation in the visible to shortwave region of the EM spectrum.
2) include in the instrument concept an optical system enhanced by advanced image processing that can acquire high resolution vegetation structure.
3) include in the instrument concept the requirement to produce instruments for diurnal sampling of spatial and spectral measurements using a modular instrument design and constellation of small satellites.
(4) through this proposed project advance the TRL level of the present instrument concept from 2 to 4.
(c) The period of performance will be January 1 2017 to June 30 2018, 18 months
(d) The entry and planned exit Technology Readiness Level (TRL) are TRL2 to TRL4.
The benefits of this proposed instrument is the first higher resolution diurnal measurements of vegetation functioning and tractable approach for reducing errors induced by scene shadows. The data can be used to assess vegetation type, health, carbon content in a variety of ecosystems. It is especially powerful in forested areas where varying shadow fraction limits the accuracy of current approaches. The results can used to monitor vegetation productivity seasonally and eventually long term to identify areas of anomalous productivity or impacts from climate change. The results can also be used to assist the use of global missions currently estimating spectral variables that can be related ecosystem productivity such as Photo Chemical Index (PRI), Solar Induced fluorescence etc.
Chris Ruf, University of Michigan
Next Generation GNSS Bistatic Radar Receiver
Global Navigation Satellite System (GNSS) bistatic radars use the existing constellations of navigation satellites (GPS, Galileo, etc.) as the transmit half of a bistatic radar link. The receive half of the link is a customized GNSS receiver designed specifically for remote sensing applications. The current state of the art in these receivers at the TRL-6 or higher level is exemplified by the science payload carried on NASA’s CYGNSS mission constellation of small satellites. This receiver demonstrated, during a recent TRL raising technology demonstration mission, that it is capable of measuring ocean surface winds, near surface soil moisture, sea surface height (altimetry), and polar ice extent from low Earth orbit. The current receiver can only process at most four simultaneous measurements and can only use the L1 signal transmitted by the GPS satellite constellation. The use of only L1 signals limits the horizontal resolution (for ocean wind, soil moisture and ice extent applications) and the vertical resolution (for altimetry). The processing of at most four signals and only from GPS satellites limits the spatial sampling and revisit time for all applications. A next generation GNSS bistatic radar receiver will be developed that is capable of processing signals transmitted by both GPS and Galileo satellites, including both low (L1/E1) and high (L5/E5) bandwidth signals. The receiver will also be capable of processing between 7 (minimum) and 14 (goal) simultaneous signals. As a direct consequence of these hardware and firmware developments, horizontal resolution will be improved by a factor of three, vertical resolution by a factor of ten, and spatial coverage and revisit time by a factor of two (minimum) to four (goal). In terms of the impact of these performance enhancements on the scientific value of remotely sensed geophysical properties, the improvements range from significant but incremental to fundamentally enabling. Examples of significant incremental improvements are the measurement of ocean surface winds and ice extent. The improved spatial resolution will, for example, enable finer spatial scale structure to be resolved in storms and smaller leads and tongues to be imaged at the polar ice edge. Examples of enabling improvements are in the areas of sea level change and flood prediction. The ability to measure sea surface height with 10X higher accuracy will place GNSS methods in the same general range of performance as existing satellite altimeter missions. The ability to measure soil moisture with high spatial and temporal resolution will enable soil saturation monitoring during potential flash flood events. In these and other ways, the next generation GNSS bistatic radar receiver will enable major improvements in climate studies, weather monitoring and prediction, disaster management, and uses by commercial maritime organizations.
This three year effort will raise the technology readiness of a Next Generation GNSS Bistatic Radar Receiver from TRL-4 to TRL-6.
Mauricio Sanchez-Barbetty, Jet Propulsion Laboratory
Multi Application Smallsat Tri-Band Radar
MASTR (the Multi-Application Smallsat Tri-band Radar) is a SmallSat instrument concept capable of electronic scanning, Doppler velocity measurement, and polarimetry at Ku/Ka/W-band frequencies. These capabilities allow MASTR to work as a cloud and precipitation radar, an altimeter (targeting sea ice height and snow depth) or as a scatterometer (in a spinning platform configuration). Consequently, MASTR has the potential to support several of NASA’s Earth science programs including Cloud and Radiation, Precipitation Measurement, Cryospheric Sciences, Climate Variability and Change, and Physical Oceanography. We propose to demonstrate AirMASTR, an airborne prototype of MASTR. The architecture uses Active Linear Array Feeds (ALAFs) made out of tiles to feed a parabolic-cylindrical reflector in the RF front end. The back end uses a baseband digital system with direct up/down conversion for a simplified instrument architecture. A modular design allows MASTR to grow in size without the need for significant redesign. MASTR was conceived to enable significantly smaller instruments that meet several science needs using a modularized architecture that is flexible and can adapt to multiple measurement objectives.
The proposed work will be divided into the following major tasks: 1) Design and Manufacture the Scanning Array Tiles (SATs) at Ku and Ka band; 2) Integrate the SATs to form the Active Linear Array Feeds (ALAF’s) that will include the new Ku and Ka band feeds with the existing W-band feed; 3) Develop the digital system and the frequency converters; 4) Integrate and Test AirMASTR with a 30×50 cm reflector; and 5) Complete a set of engineering flights aboard NASA’s DC-8 aircraft.
The entry TRL for AirMASTR will be 3, while the exit TRL will be 7 upon completion of the engineering flights. At that point MASTR can be considered to have TRL 5.
Tomasz Tkaczyk, Rice University
Tunable Light-Guide Image Processing Snapshot Spectrometer (TuLIPSS) for Earth Science Research and Observation
Objectives and Benefits We propose to develop and test a Tunable Light-guide Image Processing Snapshot Spectrometer (TuLIPSS) for future implementation on UAV, airborne, and orbiting platforms. The proposed system, when fully operational, will be able to perform a wide variety of Earth remote sensing observations. Here we focus on the development of a high fidelity functional prototype to be flight-tested on an aerial platform by the end of the funded period. TuLIPSS will be capable of acquiring instantaneous images across the visible and near-IR, with a flexible spatial/spectral resolution tradespace. This is accomplished using custom-adaptable fiber optic image processing bundles whose input is in the form of a densely-packed coherent waveguide. The optical output from each waveguide, or line of waveguides, can be flexibly designated as spatial or spectral enabling a wide variety of observational configurations.. Thus, the system’s innovative aspect is the controlled repositioning of pixels between the input and output of waveguide coherent structures, allowing efficient multi-dimensional (x, y, λ) snapshot imaging and operational flexibility. This flexibility enables a range of spatial/spectral configurations (e.g. specific sub-bands around target lines, prioritization of spatial or spectral resolution, etc.) to satisfy specific observational goals. Additionally, TuLIPSS is low resource (mass, volume, power) but highly capable.
The ability to collect data across an entire scene in a single exposure makes TuLIPSS uniquely suited to a range of Earth science applications, including the ability to record transient surface and atmospheric phenomena, and to provide multiple views through an atmospheric column for tomographic studies.
As proposed, TuLIPSS will allow:
a) snapshot hyperspectral image acquisition and high light collection efficiency
b) tunable adjustment of spatial and spectral resolution, and flexible selection of target wavelengths
c) spectral coverage across relevant wavelengths from 400nm 1000nm
d) easy exchange of image sensors, allowing different camera formats and sensitivities
e) flexibility in development of the number of input/output fiber bundles
Proposed Work and Methodology
The main project objectives include:
– Development of high resolution fiber optic bundle components and advancement of fiber bundle technology
– Development of an automatic spectral/spatial resolution tuning mechanism
– Development of automatic calibration and control routines
– System integration for VIS-NIR imaging range
– Testing in airborne environment
The basic principal of the spatial/spectral image processing methodology proposed here is the coupling of fore optics to a light-guide image processor (LIP) that distributes the incoming photons to a sensor array in a flexible, application-specific manner, describing spatial and spectral information. In this project we will develop a system capable of automatic adjustment of sampling. Three main configurations will include 400x330x30 to 250x210x80 and 150x125x250 cube size where the numbers denote the ranges in the two spatial and one spectral dimensions. The camera used to assemble the system will be PCO Edge 5.5 capable of recording relevant signals in the 400-1000 nm range. TuLIPSS will allow selection of the sub-band at selected spectral-spatial sampling. Note: the spectral range can be expanded by incorporating a second focal plane array sensitive to 1000-1900 nm range. This extension will be considered in subsequent projects.
Period of Performance Duration of the project is three years.
Entry and Planned exit TRL The proposed system has been developed beyond the breadboard stage and is currently estimated to be at TRL 3. The system is well-matched to reach a level of TRL 5 by the end of the funding period.
Dong Wu, Goddard Space Flight Center
SWIRP: Compact Submm-Wave and LWIR Polarimeters for Cirrus Ice Properties
Clouds remain as a major source of uncertainty in climate models. Ice clouds, in particular, are poorly constrained and have been used as a tuning parameter in the models to balance radiation budget at the top of atmosphere and precipitation at the surface. Lack of accurate cloud ice and its microphysical property measurements has led to large uncertainty about global clouds and their processes within the atmosphere. NASA’s Aerosol, Cloud and Ecosystems (ACE), an Earth Science Decadal Survey (DS) mission, recommended an advanced science payload with submm-wave and longwave infrared (LWIR) radiometers for such cloud ice measurement. In a recent community white paper, Cloud and Precipitation Process Measurements (CaPPM), dynamics and microphysical properties are identified as the key links between the cloud-precipitation pro-cesses and need more accurate measurements.
In this project we will develop a compact Submm-Wave and LWIR Polarimeters (SWIRP) in-strument to enable accurate measurements of cloud ice and its microphysical properties (particle size and shape). Radiometric and polarimetric measurements from the proposed submm (220 and 680 GHz) and IR (8.6, 11, and 12 μm) bands, providing the needed sensitivity over a full dynam-ic range of cloud ice, will be used jointly in cloud retrievals. The conical scanning configuration with SWIRP will preserve horizontal (H) and vertical (V) polarization information for bulk cloud particle shape retrievals while the SWIRP’s matched submm and LWIR footprints will allow the joint retrieval of cloud particle size with these frequency bands. The compactness of SWIRP de-sign enables cost-effective deployment of these radiometers-polarimeters on future large space-flight missions (e.g., ACE), or on small distributed flight systems for rapid update and frequent revisit sampling to study fast atmospheric processes. In IIP-16 we will substantiate the technical feasibility of miniaturizing mm/submm polarimet-ric direct-detection receivers, a novel multi-channel LWIR spectro-polarimeters, and a compact Bearing and Power Transfer Assembly (BAPTA) for conical scanning observations. We will build a prototype instrument with self-calibration in a volume of 20x20x40 cm, and complete laboratory environmental and rooftop tests at the end of project. The entry level for the proposed instrument is TRL=3, and it will reach TRL=5 within the 3-year period of performance.
Lauren Wye, SRI International
SRI CubeSat Imaging Radar for Earth Science: Instrument Development and Demonstration (CIRES-IDD)
Space-based interferometric synthetic aperture radar (InSAR) is a key change-detection tool in NASA’s Earth Science Division portfolio. InSAR addresses three of the seven major themes summarized by the National Research Council Earth Sciences Decadal Survey: 1) solid-earth hazards and dynamics; 2) human health and security; and 3) land-use change, ecosystem dynamics, and biodiversity. All require global, frequent assessments of solid surface deformation via InSAR measurements.
For maximum impact, InSAR measurements must be precise (sub-cm level) and timely. Frequent acquisitions (sub-weekly) are needed to provide enhanced deformation precision through time series averaging, and ensure that an event is properly captured and characterized. Orbital mechanics prevent single-platform sensors from simultaneously achieving rapid revisit times and wide-area coverage. Multiple platforms are needed to avoid compromising coverage, but traditional InSAR sensors are too expensive (> $300M) to replicate.
Under the NASA ESTO IIP program, SRI International (SRI) and our team of collaborators propose to develop a complete SAR/InSAR instrument for CubeSats. The instrument is called CIRES-IDD (CubeSat Imaging Radar for Earth Science Instrument Development and Demonstration). We will leverage SRI’s TRL-5 CIRES radar hardware developed under NASA ACT funding, SRI’s TRL 4 image formation software, and a TRL-3 high-gain deployable membrane antenna to form the complete instrument.
CIRES-IDD is a three-year program with ground and airborne unmanned aerial systems (UAS) demonstrations to retire technology risks and raise the CIRES-IDD system TRL from 3 to 6 in preparation for a future orbital demonstration campaign. The planned IIP period of performance is from 9 January 2017 to 8 January 2020. The following points summarize the maturation plan for each technology piece.
We will start by maturing the SAR/InSAR image-processing solution. SRI will apply their extensive set of SAR algorithms and coherent registration techniques to CIRES-IDD. We will test and debug the developed software on the UAS platform, followed by a rigorous calibration campaign. SRI experience with adapting the image formation tools to different systems (e.g., operational TRL-9 airborne radar systems) enables a relatively straightforward algorithm development path based on previously proven techniques.
Our antenna partner, Physical Sciences Inc. (PSI), will develop the high-gain deployable membrane antenna (>36 dBi). PSI will iteratively develop and test increasing scales of antenna test articles, focusing on deployment, tensioning, packaging efficiency, and RF performance. Antenna risk reduction tests will include microgravity deployment and folding tests, among others.
Working with NASA Ames Research Center and the NASA Airborne Science Program, we will execute four UAS flight campaigns to validate CIRES-IDD utility at altitude. These flights will demonstrate the full SAR/InSAR performance capabilities (25-m imaging resolution, sub-cm-level InSAR accuracy, SNR >13 dB) and demonstrate scientific relevance. We have partnered with Jet Propulsion Laboratory, Stanford University, and the U.S. Geological Survey to identify local areas of interest and assist with analyzing and assessing the utility of the data for scientific research.
The lessons learned from UAS testing will be used to optimize the CIRES-IDD design features such as thermal resilience, power management, mass, volume, and sensor capabilities, thereby improving system performance and reducing risks for future on-orbit operations. Although the proposed project’s ultimate goal is to prepare and prove CIRES-IDD for future on-orbit CubeSat operations, the UAS SAR system resulting from this effort will become a useful scientific research platform in its own right, a capability also valued in the Decadal Survey.