Airborne (suborbital) science: Platforms and sensors

12+ in attendance

Scott Ollinger (co-chair) Dar Roberts (co-chair)

Collective Expertise: LIDAR, Interferometric radar imaging

spectroscopy, UAV development and testing (NASA and USDA),

rapid response systems, fire detection, thermal imagery, sensor

webs, Several new NSF initiatives (CUAHSI, NCALM, HAIPER)

1. What1. What are the Terrestrial Ecology, Biodiversity, and Appl are the Terrestrial Ecology, Biodiversity, and Appl ied Sciences ied Sciences Community’s current and future needs for suborbital observations?Community’s current and future needs for suborbital observations?

Important contributions of aircraft remote sensingImportant contributions of aircraft remote sensing

• Sensor test bed (Provides a platform for sensor testing and algorithm development

• Unique sensors (HF imaging spectrometers, small foot print LIDAR, LVIS, FLIR, FLEX, P-band SAR, ATLAS)

• Control over timing of data acquisition (critical)

– Improved cloud avoidance (data acquisition under or around clouds)– Multiple times of day (e.g. target specific tidal stage, sun angle or plant stress level) – Rapid deployment following disturbance (fires, floods, insect outbreaks)– Extended periods of data collection

• Multiple sensor altitude - Variable (Scalable) spatial resolution (<1m to ~ 20 m)

• High Informational Resolution (Spectral, polarimetric and vertical)– Fine spectral resolution (Imaging Spectrometers) - Discrimination of species, chemistry and physiological function.

– Multi-frequency, fully polarimetric radar (Penetration depth, soil moisture & flood status, vegetation structure). Frequency allocation and band width issues limit capacity in space.

• Control over Sun-Earth-Sensor geometry (timing, flight trajectory, BDRF)

• Multisensor integration Many sensor combinations possible at multiple scales

• Data quality/Sensor evolution - Opportunities for repeat calibration, repair and upgrade.

• Cost/Development cycle – Aircraft missions can be quick andquick and cost effective as compared to satellite missions.

1b. Limitations/Challenges with Aircraft Data1b. Limitations/Challenges with Aircraft Data

• Limited spatial & temporal coverage

• Difficult Georectification

• Intractability to many users– Perception (sometimes real & unavoidable) of data being difficult to

access and work with.– Perception (sometimes real, but avoidable) of aircraft remote sensing

being a hard community to break into.– No (or limited) distribution of standard data products, restricts use by

those lacking specific skills.

2. Recognizing that the NASA Suborbital Science program is 2. Recognizing that the NASA Suborbital Science program is evolving and that repeated attempts to secure new funds for evolving and that repeated attempts to secure new funds for new airborne sensors have failed, how should our community new airborne sensors have failed, how should our community respond, adjust and adapt?respond, adjust and adapt?

What should we do???What should we do???

• We should know how many non-NASA sensors (i.e. University, private etc.) exist along with availability/quality?

• Education – Airborne program can be taken for granted. Need to inform/remind scientists, management, congress, etc. of the value of the airborne program.

– Need for a review article on the contributions of aircraft remote sensing to ecological research. POSSIBLE JOURNALS: BIOSCIENCES, FRONTIERS in ECOLOGY, ECOLOGICAL APPLICATIONS

• Improve dissemination and use of aircraft data– Should NASA encourage development of data products from airborne sensors?– Should there be an aircraft data DAAC or equivalent?– Should NASA have specific calls for suborbital science & product development?

• Interest in aircraft RS is growing in other agencies while resources at NASA remain flat. Provide feedback to program managers (at NASA and other agencies) where synergy exists with initiatives by other agencies

3. What are the Terrestrial Ecology, Biodiversity, and Applied Sciences needs for unpiloted aerial vehicles (UAVs)?

• UAVs are appropriate for tasks that are Dull, Dirty or Dangerous– Long duration, high altitude, plume dispersal & fires, very low altitude– Long duration eddy flux– Fire dynamics– Phytoplankton blooms– Natural hazards requiring long duration, repeat passes

• UAV Attributes– Cost:

• Small UAVs can be cost effective and many are available• Large UAVs are generally very expensive (cost/flight hour/pound payload: UAVs 10x more than existing

piloted aircraft.• Medium-sized UAVs are presently lacking, but may be forthcoming

– Higher risk of crash

– Cannot fly over commercial airspace

• What UAVs are available? See: – http://uav.wff.nasa.gov/ – http://suborbital.nasa.gov/– http://nirops.fs.fed.us/UASdemo/– Payloads from 20 - 3000 kg

Tentative Paper Outline

•Title: “The unique role of aircraft remote sensing in ecological research”

–Ecological Needs for Remote Sensing (broadly)Ecological Needs for Remote Sensing (broadly)–Specific contributions of airborne sensorsSpecific contributions of airborne sensors

•Types of ecological measurementsTypes of ecological measurements–Niche of Airborne Sensors relative to Spaceborne sensorsNiche of Airborne Sensors relative to Spaceborne sensors–Historical Role of Airborne SensorsHistorical Role of Airborne Sensors–Case studiesCase studies–Future DirectionsFuture Directions

Additional Questions• What other non-NASA programs exist that have a current or future need for aircraft remote

sensing?– How could NASA or the user community go about making the link between these agencies?– NCALM: University of Florida, UC Berkeley, Arizona

• NSF Consortium: National Center for LIDAR• LIDAR system• Could this be a model we could use?

– Are there other NSF initiatives that could be used similar to NCALM?• Yes: HAIPER: NCAR, gulf stream 5 jet, currently atmospheric focus, some interest in other sensors,

routine data collection• NSF program managers would like it to be broader (Bulletin American Meteorological Society – BAMS)

• What unique measurements can be made that do not compete with private assets?– How do you avoid competition with industry?: Focus on research emphasis

• To what extent are aircraft missions useful beyond their service as a test bed for planned spaceborne missions?

• How will the suborbital program be impacted by and react to the decadal survey?• What is the mechanism for downsizing sensors to fit on a UAV?• What should the balance of funding be for PI sensors/Univ sensors vs facility sensors?

– Interdisciplinary nature of facility sensors– What is the community preference?– Availability of facility vs PI sensors

Discussion Questions

• What are the Terrestrial Ecology, Biodiversity, and Applied Sciences Community’s current and future needs for suborbital observations?

• Alternative question: How does the suborbital platform program contribute to TE, Biodiv and ASP?

What might an Ecologist want to know?

• What is there (PFT, Species)?– TE, Biodiversity, invasions, phytoplankton/algae, coral, submerged aquatic vegetation

• How much is there (plant cover)?– TE, Biodiversity and invasions

• What is its physiological status?– Vegetation health, chemistry, carbon exchange, LUE, NPP, etc.

• What is its structure, biophysical properties?– Height, biomass, LAI, roughness, albedo, subcanopy

• What is the senesced biomass?• How is it changing?

– Land-cover change, forest degradation, aforestation, invasion• How do these properties vary with spatial, spectral and temporal scale?• What are the geological/soil properties (chemistry, texture), soil exposure, erosion,

soil moisture• What are the atmospheric properties?• What is its temperature and emissivity?• For water, what is its depth, sediment concentration, current, waveheight, pigments

Ecological Contributions of Airborne Platforms (Part I)

• Fine to moderate spatial resolution (variable spatial resolution)– For some applications, resolutions ~ 3 m or less are needed

• Multiple sensor altitudes (atmospheric measurements, multibaseline)• Fine spectral resolution (AVIRIS)

– Improves PFT or species discrimination, provides a suite of physiologically meaningful measures, improves biophysical retrievals, water vapor, trace gases and aerosols, chemical diversity (biodiversity)

• Multifrequency, fully polarimetric– Frequency allocation issues limit capacity in space, P band in space, wide band width SAR not

possible from space– Penetration depth, soil moisture, flooded vegetation, structure (tree height, biomass classes)– higher SNR

• Timing (critical)– Provides improved cloud avoidance, data acquisition under clouds, flexibility to support field

campaigns, meet timing requirements (ie, coastal tides) – Provides non-sun synchronous acquisitions, night imaging– Can explore variability in viewing vs solar geometry (scan angle, BRDF)\

• Trajectory control, relative overlap between flight lines etc.• AIRMISR – Multiangle along multiple trajectories

– Contributes timely data (ie, southern California fire storm)Hazards (earthquakes, floods, fires) – need timely, immediate data acquisition following disturbanceInsect outbreaks

– Persistence (dwelling over one spot for an extended period of time (fire monitoring, evapotranspiration, carbon release), daily repeat passes

Ecological Contributions of Airborne Platforms (Part II)

• Unique sensors– HF Imaging Spectrometry (AVIRIS), Small footprint LIDAR, LVIS, FLIR, Fluorescence (FLEX), polarimetric (P

band), no single pass interferometer, multispectral high spatial resolution thermal (ATLAS, MASTER, Autonomous Modular Sensor (AMS)), eddy covariance

• Data continuity at an appropriate spatial scale– Long term sampling (ie, long term resampling of a site with the same or similar sensors)– Improved data continuity by persistence

• Multisensor integration– An imaging spectrometer can be used to simulate other sensors– Critical for scaling between ground and space– Synergistic use of sensors (combination of two or more sensors): Need good validation from an airborne program

• Sensor Test bed– Provides a platform for testing out sensor concepts, technology components and measurement strategies– Provides a platform for algorithm development and testing, evaluating potential sensor web configurations

• Calibration/Validation of spaceborne sensors• Sensor repair• Data Quality (can be improved between flight seasons)

– Quality of calibration, daily calibration– Many commercial sources do not provide science quality data

• Sensor evolution– Sensors can be improved over multiple flight seasons (AVIRIS, AIRSAR)

• Cost – Aircraft missions can be cost effective when satellite missions are not possible• Development cycle – Can be compressed significantly with an airborne system: 1-2 years• Educational potential

Advantages and Limitations of Spaceborne Sensors for Ecology

• Advantages– Global sampling, global access– Variable swaths, local (ASTER) to continental (MODIS)– Repeat sampling (high frequency, daily, multi-day, monthly)– Well understood surface tracks, illumination and viewing geometry– Sensor legacy (ie, Landsat Continuity) – Reduced geometric distortion– No airspace restrictions– Very high national and international contribution to agencies, research, education– Prestige, public awareness

• Limitations– Spatial/spectral resolution tradeoffs– Fixed spatial scales– Band width limitations– Inflexible acquisition times– Inflexible orbits– High sensor and launch costs, long development cycle– Limited sensor availability (ie, LIDAR, P-band SAR, hi-fidelity imaging spectrometry)– Limited sensor evolution, difficulty to repair (ie, Landsat ETM+)– Calibration drift– Orbital instability (georectification issues)

Limitations and Advantages of Spaceborne Sensors for Ecology

Question 2: Part 1• Recognizing that the NASA Suborbital Science program is evolving and that repeated attempts to secure new funds for

new airborne sensors have failed, how should our community respond/adjust/adapt?• There should be consideration of other programs, such as NSF/NEON (Scott Ollinger)

– NSF calls for sensor development (MREFC): NEON 400-500 million dollars, CLEANER (Collaborative Large Scale Engineering Analysis Network for Environmental Research) hydrology eng: water quality), CUAHSI (Consortium of Universities for Advancement of Hydrological Science Incorporated) hydrology, environmental engineering: Water supply)

– NSF 6 million central NEON office (call, 2 years ago, Bruce Hayden: NEON Inc). – 7 out of 8 groups considered aircraft remote sensing as a core set of requirements for a NEON network (Imaging Spectrometry and

LIDAR).– Partnerships with NASA and other agencies, where one could develop it, the other deploy– Concern: Advice given in design consortium did not acknowledge potential contribution of NASA, no representatives from NASA

(NEON project implementation committee).– Concern: NASA/NSF should coordinate on compatibility (je, an instrument that can fly on many platforms)– What can we do as a community to push these things through?

• Other programs– SBIR, Naval Postgraduate School, EPA, NOAA, DOE– Recommendation: What kinds of sensors could be developed through an SBIR?

• NASA should be encouraged to partner or facilitate agreements with NSF to aid NEON– NASA must be encouraged to understand the advantageous of a partnership with NSF– NEON/NSF needs to agree to support NASA efforts with its ground based observations– NASA should support NSF/NEON in the development of sensors that complement NASA capabilities

• NSF needs feedback from the science community of the importance of NASA technology to their program• University/Institutional efforts

– ie, Carnegie waveform small foot print LIDAR, Imaging Spectrometry– NCALM (University of Florida, UC Berkeley, Arizona)– University sensors (ie, U Nebraska AISA, University of Texas (waveform LIDAR))– Sensor integration support (UC Santa Cruz: Airborne Science and Technology Laboratory: Jeff Myers contact)

• International collaborations• Commercial sensors

– NASA has RFIs that allow an investigator to request a commercial sensor– NASA would appreciate knowledge of your requirements

Question 2: Part 2• Recognizing that the NASA Suborbital Science program is evolving and that repeated attempts to secure

new funds for new airborne sensors have failed, how should our community respond/adjust/adapt?• We should know how many non-NASA sensors (ie, University etc) exist?

– We should have a table of existing sensors– What exists and how accessible is it and what is its quality?– NASA should set minimum data quality standards

• Perhaps the Instrument Incubator Program could be used• NASA has invested considerable funds in UAV SAR – how might this engineering model be adapted

for use with a different sensor package or support a different science objective (ie, canopy height)• Outreach/education – why do management, congress, scientists etc. not perceive the value of the

airborne program?– How do we change perceptions?

• The data are difficult to work with• The data are only accessible to a small “club”• There are no standard data products• Should there be an AIRCRAFT DAAC for Data or example data?• Should PIs be required to provide examples of their work• Location of data sets should be reported

– Data should be made more accessible to the user community• Difficulty in getting data when you needed it• Difficulty in processing data

– The community may not perceive what the airborne program and the individuals involved contribute to the success of a mission

• Reference the airborne program?– Is there a document that outlines the unique contributions of a suborbital platform?

• TARGET JOURNAL: BIOSCIENCES, FRONTIERS in ECOLOGY

• NASA should be encouraged to have specific calls for suborbital science– Requirements for data release (spelled out in the call)

Question 3: Part IWeb sites: http://uav.wff.nasa.gov/

http://suborbital.nasa.gov/platforms/platforms.html

• What are the TE, Biodiv, and ASP needs for unpiloted aerial vehicles (UAVs)? How should we take advantage of current investments in UAV technology?

• When is a UAV appropriate (the cost of UAVs is really high, so you need a good justification)

– Justification: Tasks that are Dull, Dirty or Dangerous– Long duration, high altitude, autonomy (ie, guided by sensor input to tell it where the optimal

flight lines are through a sensor web), volcanic plumes, smoke (dirty), too dangerous (fire, or very low altitude such as eddy covariance over tree tops), Boreas (flux tower repeat flights)

• What UAVs are available? (see http://uav.wff.nasa.gov/ for a more complete list, that is still out of date)

– http://nirops.fs.fed.us/UASdemo/ (see photogallery at bottom: ~ 20 lbs)– Ikhana (predator)– Aerosonde (leased from AAI)– Sierra (AMES)– Altair (Lease arrangement with General Atomics)– Proteus (normally piloted): leased from Scaled Composites

• What does NASA have now?– Sierra (still under construction at NASA Ames)

• 100 lbs– Predator B (ikhana): Delivery in Fall 06– Global Hawks (Dryden): possession in 2007, control later

Question 3: Part IIWeb sites: http://uav.wff.nasa.gov/

http://suborbital.nasa.gov/platforms/platforms.html• What are the TE, Biodiv, and ASP needs for unpiloted aerial vehicles (UAVs)? How should we take advantage of current investments in UAV

technology?• UAV Attributes

– What is the cost?• Altair: Currently cost prohibitive (hugely expensive compared to manned assets)• Ikhana: Actual cost unknown, likely to be costly but when assessed by flight hour might match manned assets• Global Hawk: unkbnown costs• Metric: cost/flight hour/pound payload: UAVs 10x more pricey

– What are the flight attributes? (ie, speed, elevation, stability)• Altair: up to 36 hours continuous flight, altitude 52,000 feet, up to 1000 lbs (depends on sensor pod limitations)

– What is the payload?• Altair 1000 lbs, same as Ikhana• Global Hawk: 2-3000 lbs

– Flight limitations/liability• Can your sensor be adapted to work with a UAV?• NASA is currently heavily invested in UAVs. How might this capability be used?

– UAVs are not the answer to all problems (Scott)• How much do you care about your sensor?

– UAVs crash more often• Which smaller UAVs exist

– See http://uav.wff.nasa.gov– See http://nirops.fs.fed.us/UASdemo/ – Past workshops: see http://suborbital.nasa.gov/technology/partnership.html

• What are some examples of TE applications suitable for a UAV?– Diurnal sampling of reflectance– Long duration eddy flux– Fire dynamics– Antarctic coastal flights – Phytoplankton blooms– Any natural hazard requiring long duration, repeat passes– Plume dispersal (water or air)

Additional Questions

• What other non-NASA programs exist that have a current or future need for aircraft remote sensing?– How could NASA or the user community go about making the link

between these agencies?

• What unique measurements can be made that do not compete with private assets?

• To what extent are aircraft missions useful beyond their service as a test bed for planned spaceborne missions?

• How will the suborbital program be impacted by and react to the decadal survey?

• What is the mechanism for downsizing sensors to fit on a UAV?

Additional Questions• What are the mission concepts that could take advantage of the unique

attributes of UAVs?– Long duration flights either required for diurnal studies or long range acquisition

(ie, southern Ocean)– CO2 sniffer for validation of OCO and towers (remote areas): Small package

(NOAA, modified LICOR 7550: IRGA)• Night time fluxes

– Coastal blooms (need for continuous measurements)– Forest fire emissions and dynamics (spread, intensity)

• Fires, dwelling (time series), perimeters– Circumnavigation of ice sheets (antarctic)– Real-time data acquisition at fine spatial resolution

• UAV often has a high band width satellite link that can be taken advantage of. This is also more cost effective than a satellite for onboard processing

• How much might we gain from this type of real-time potential?– Example, plant fluorescence

– Potential of continental scale mapping made possible by long duration capabilities of UAV using an active sensor (ie, LIDAR power various with square of distance, so this translates to a lower power need for a laser)

– Ideal platform for testing out microsat constellation

Action Items

• Journal Article on Ecological Advantages of airborne platforms?– Target Bioscience, Frontiers in Ecology, Ecological

Applications, Summary in EOS– Participants

• Jeff Luvall (thermal), Matt Fladeland (UAV, past flight requests, historical program), Scott Ollinger (imaging spectrometry), Dar Roberts (imaging spectrometry), Michelle Hofton (LIDAR), Susan Ustin, Greg Asner, Robert Green

• Map of US showing where aircraft sensors have been flown, existing archives

Key bullets: Day 1• We identified a number of benefits of aircraft remote sensing that cannot be

replaced by satellites– Summarize this list (or for example)

• Outreach– Knowledge of benefits of suborbital science program is poor in important

components of the scientific community– We need a paper that summarizes the ecological strengths of an airborne

program– Working with non-NASA programs that have needs for aircraft remote sensing

(NEON) or taking advantage of existing non-NASA, public resource • UAVs

– To date there is no evidence that they are likely to be an effective replacement of current aircraft, but could enhance or complement these programs (cost prohibitive)

– There are unique ecological questions that probably can only be addressed using an UAV (long duration requirements, dangerous acquisitions)

– Excellent UAV information exists

Airborne (suborbital) science: Day 2 Platforms and sensors

Scott Ollinger, Dar Roberts10 in attendance

Rob Sohlberg (UAV, rapid response, sensor webs))Robert Green (AVIRIS)

Cheryl Yuhas (Suborptical management)Matt Fladeland (Suborbital, UAV etc)

Emily Wilson (NASA Goddard)Nicholas Coops

Paul Siqueira (JPLAmy Neuenschwander (U Texas)

Greg Asner (Carnegie)Susan Ustin (UC Davis)