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Suborbital Instruments and Sensor Systems for Earth ScienceMeasurements


Scope Title:

Sensorsand Sensor Systems Targeting Aerosols andClouds

NASA seeks measurement capabilities that supportcurrent satellite and model validation, advancement of surface-basedremote-sensing networks, and targeted Airborne Science Program andship-based field campaign activities as discussed in annual NASAROSES solicitations. Data from such sensors also inform processstudies to improve our scientific understanding of the Earth system. Insitu sensor systems (airborne, land, and water-based) can comprisestand-alone instrument and data packages; instrument systems configuredfor integration on ship-based (or alternate surface-based-platform) andin-water deployments, NASA’s Airborne Science aircraft fleetor commercial providers, UAS, balloons, or ground networks; orend-to-end solutions providing needed data products from mated sensorand airborne/surface/subsurface platforms. An important goal is tocreate sustainable measurement capabilities to support NASA’sEarth science objectives, with infusion of new technologies and systemsinto current/future NASA research programs. Instrument prototypes as adeliverable in Phase II proposals and/or field demonstrations are highlyencouraged. 

Complete instrument systems are generally desired,including features such as remote/unattended operation and dataacquisition, and minimum size, weight, and power consumption. Allproposals must summarize the current state of the art and demonstratehow the proposed sensor or sensor system represents a significantimprovement over the state of the art.  


Specific desired sensors or mated platform/sensorsinclude: 

  • Small, low-cost multi-angle and multi-spectral (350to 1600 nm wavelengths) imager suitable for airborne observations ofcloud fraction and stereo-derived structure. 
  • High-size- and high-time-resolution measurements ofthe dry aerosol electrical mobility size distribution (10 to 1000 nmdiameter) at 1 Hz suitable for deployment on aircraft from the surfaceto 43,000 ft altitude. 
  • Aerosol absorption coefficient covering the 400 to800 nm spectral range for deployment on aircraft from the surface to43,000 ft altitude; non-filter-based techniques (e.g., photoacousticspectroscopy) are preferred over filter-based instruments, but theinstrument must be robust to temperature and pressure changesencountered during airborne operation. 
  • Aerosol scattering or extinction coefficientcovering the 400 to 800 nm spectral range for deployment on aircraftfrom the surface to 43,000 ft altitude, where the instrument is robustto temperature and pressure changes encountered during airborneoperation. 
  • Aerosol scattering as a function of scattering angle(phase function or, preferably, phase matrix) .
  • Aerosol complex refractive index. 
  • Aerosol and cloud particle number and sizedistribution covering the diameter size range of 0.01 to 200µm with 10% accuracy under ambient (i.e.,unperturbed) temperature, relative humidity, and pressure conditions.Probes targeting cloud particles in the lower end of this size range(0.01 to 5 µm) are particularly encouraged. 
  • Cloud probes able to differentiate and quantifynonsphericity and phase of cloud particles. 
  • Liquid and ice water content in clouds withcalibrated accuracy and precision. 
  • Liquid and ice water path in relevant tropical,midlatitude, and/or polar environments, including data inversion andanalysis software. 
  • Spectrally resolved cloudextinction. 
  • Static air temperature measured from aircraft tobetter than 0.1 °C accuracy. 
  • Isokinetically controlled aircraft aerosol inletsable to transmit both submicron-sized particles as well as those greaterthan 5 µm in diameter at airspeeds typical of theNASA P-3B, 777-200ER, and G-III/IV/V aircraft. 
  • Autonomous aerosol optical depth (AOD)ultraviolet-visible-near-infrared (UV-vis-NIR) (340 to 900nm) hyperspectral plus short-wave-IR- (SWIR-) bandsensor for shipboard-based measurements. 
  • Innovative, high-value sensors directly targeting astated NASA need (including trace gases and ocean hyperspectralUV-vis-NIR water-leaving radiance and inherent optical properties) mayalso be considered. Proposals responding to this specific bullet arestrongly encouraged to identify at least one relevant NASA subjectmatter expert. 


The S11.05 subtopic is and remains highly relevantto NASA SMD and Earth Science research programs, in particular the EarthScience Atmospheric Composition, Weather and AtmosphericDynamics, Climate Variability and Change, and Carbon Cycleand Ecosystems focus areas as well as Applied Sciences. In situand ground-based sensors inform NASA ship and airborne science campaignsled by programs in these focus areas and provide important validation ofthe current and next generation of satellite-based sensors (e.g., PACE,TEMPO, OCO-2, OCO-3, MAIA, GLIMR, SBG, and AOS). The solicitedmeasurements will be highly relevant to future NASA campaigns(Arctic-COLORS), with objectives and observing strategies similar topast campaigns (e.g., ARCSIX, ASIA-AQ, CAMP2EX, FIREX-AQ, KORUS-AQ,DISCOVER-AQ, NAAMES, and EXPORTS). 

Expected TRL or TRL Range at completion of theProject: 4 to 7

Primary TechnologyTaxonomy:

  • Level 1 08 Sensorsand Instruments
  • Level 2 08.3In-SituInstruments/Sensor

DesiredDeliverables of Phase I and PhaseII:

  • Prototype
  • Hardware
  • Software

DesiredDeliverables Description:
The ideal Phase I proposal would demonstrate a clearidea of the problem to be solved, potential solutions to this problem,and an appreciation for potential risks or stumbling blocks that mightjeopardize the success of the Phase I and II projects. The ideal Phase Ieffort would then address and hopefully overcome any major challenges to(1) demonstrate feasibility of the proposed solution and (2) clear theway for the Phase II effort. These accomplishments would be detailed inthe Phase I final report and serve as the foundation for a Phase IIproposal. 

The ideal Phase II effort would build, characterize,and deliver a prototype instrument to NASA, including necessary hardwareand operating software. The prototype would be fully functional, but thepackaging may be more utilitarian (i.e., less polished) than acommercial model. 

State of the Art and CriticalGaps:

The subtopic is and remains highlyrelevant to NASA SMD and Earth Science researchprograms; in particular, the Earth Science AtmosphericComposition, Climate Variability and Change, and Carbon Cycleand Ecosystems focus areas. Suborbital in situ and remote sensors informNASA ground, ship, and airborne science campaigns led by these programsand provide important validation of the current and next generation ofsatellite-based sensors (e.g., PACE, OCO-2, OCO-3, MAIA, TEMPO, GLIMR,SBG, AOS; see links in References). The solicited measurements will behighly relevant to current and future NASA campaigns with objectives andobserving strategies similar to past campaigns (e.g., ACTIVATE, NAAMES,EXPORTS, CAMP2EX, FIREX-AQ, KORUS-AQ, and DISCOVER-AQ; see links inReferences). 

Relevance / ScienceTraceability:
The subtopic is and remains highly relevant to NASASMD and Earth Science Division (ESD) research programs; inparticular, the Earth Science Atmospheric Composition, Weather andAtmospheric Dynamics, Climate Variability and Change, CarbonCycle and Ecosystems, and Earth Surface and Interior focus areas. Insitu and ground-based sensors inform NASA ship and airborne sciencecampaigns led by these programs and provide important validation of thecurrent and next generation of satellite-based sensors (e.g., PACE,OCO-2, OCO-3, MAIA, TEMPO, GLIMR, SBG, A-CCP; see links in References).The solicited measurements will be highly relevant to future NASAcampaigns with objectives and observing strategies similar to currentand past campaigns (e.g., ARCSIX, ASIA-AQ, ACTIVATE, NAAMES, EXPORTS,CAMP2EX, FIREX-AQ, KORUS-AQ, DISCOVER-AQ; see links in References). Theneed horizon of the subtopic sensors and sensors systems is bothnear-term (<5 yr) and midterm (5 to 10 yr). 


Relevant programs and program officersinclude: 

  • NASA ESD Radiation Sciences Program (Hal Maring, HQProgram Scientist) 

  • NASA ESD Tropospheric Composition Program (BarryLefer, HQ Program Scientist) 

  • NASA ESD Upper Atmosphere Research Program (KenJucks, HQ Program Scientist) 

  • NASA ESD Ocean Biology and Biogeochemistry Program(Laura Lorenzoni, HQ Program Scientist) 

  • NASA ESD Weather and Atmospheric Dynamics Program(Tsengdar Lee and Will McCarty, HQ Program Scientists) 

  • NASA ESD Earth Surface and Interior Program (BenPhillips and Kevin Reath, HQ Program Managers) 

  • NASA ESD Airborne Science Program (Bruce Tagg, HQProgram Scientist) 

NASA Airborne Science Program aircraft include: 


Relevant current and past satellite missions andfield campaigns include: 

  • Decadal Survey recommended Atmosphere ObservingSystem (AOS) mission focusing on aerosols, clouds, convection, andprecipitation:
  • OCO-2 satellite mission that targets spaceborneobservations of carbon dioxide and the Earth’s carboncycle:
  • OCO-3 satellite mission that extends NASA’sstudy of carbon from the International Space Station (ISS): 
  • MAIA (Multi-Angle Imager for Aerosols) Mission thatwill make radiometric and polarimetric measurements needed tocharacterize the sizes, compositions and quantities of particulatematter in air pollution:
  • TEMPO satellite mission focusing on geostationaryobservations of air quality over North America:
  • PACE satellite mission that focuses on observationsof ocean biology, aerosols, and clouds:
  • SBG satellite mission focuses on observations ofaquatic and terrestrial ecology:
  • GLIMR satellite mission observes and monitors coastalocean biology, biogeochemistry and ecology:
  • ARCSIX airborne field campaign targeting the Arcticsurface-aerosol-cloud-radiation system:
  • ASIA-AQ airborne field campaign targeting pollutionand urban air quality in Asia: 
  • Arctic-COLORS field campaign studies land-oceaninteractions in a rapidly changing Arctic coastal zone, andassesses vulnerability, response, feedbacks and resilience ofcoastal ecosystems, communities, and natural resources to current andfuture pressures (field work to begin in 2025 and extend to2028): 
  • CAMP2Ex airborne field campaign focusing on tropicalmeteorology and aerosol science:
  • FIREX-AQ airborne and ground-based field campaigntargeting wildfire and agricultural burning emissions in the UnitedStates:
  • ATom airborne field campaign mapping theglobal distribution of aerosols and trace gases from pole-to-pole: 
  • KORUS-AQ airborne and ground-based field campaignfocusing on pollution and air quality in the vicinity of the KoreanPeninsula:
  • DISCOVER-AQ airborne and ground-based campaigntargeting pollution and air quality in four areas of the United States:
  • NAAMES Earth Venture suborbital field campaigntargeting the North Atlantic phytoplankton bloom cycle and impacts onatmospheric aerosols, trace gases, and clouds: h
  • EXPORTS field campaign targeting the export and fateof upper ocean net primary production using satellite observations andsurface-based measurements:

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