** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** UNDERSTANDING THE STRUCTURE AND FUNCTION OF FORESTS ESPECIALLY THEIR UNDERSTORIES AND CANOPIES IS BOTH AN ESSENTIAL AND CHALLENGING PURSUIT IN ENVIRONMENTAL SCIENCE. AN ABILITY TO MAP AND MEASURE UNDERSTORY AND CROWN STRUCTURES SUCH AS STEMS BRANCHES TWIGS AND LEAVES IN FINE DETAIL HOLDS SIGNIFICANT IMPLICATIONS FOR THE BURGEONING CARBON MARKET AND IMPROVED TIMBER HARVESTING OPERATIONS. WHEN APPLIED ACROSS WIDE SPATIAL SCALES THIS CAPABILITY COULD FURTHER ENHANCE FOREST FIRE VULNERABILITY ASSESSMENTS PREDICTIONS AND SUPPORT HOLISTIC FOREST MANAGEMENT AND MONITORING STRATEGIES.DATA ACQUISITION TOOLS ARE NEEDED TO ACHIEVE THIS LEVEL OF DATA COLLECTION. AN EXCELLENT CANDIDATE FOR THIS TASK IS A UAV (UNOCCUPIED AERIAL VEHICLE) CAPABLE OF AUTONOMOUSLY TRAVERSING SUCH COMPLEX ENVIRONMENTS AS DENSE FOREST UNDERSTORIES AND INTRA-CROWN SPACES (WHICH COMBINED WITH UPPER CANOPY STRUCTURES FORMS THE COMPREHENSIVE ABOVEGROUND SPACE OCCUPIED BY VEGETATION HEREBY CALLED THE 'VEGETATION DOMAIN'). WHILE THE EVOLUTION OF UAV TECHNOLOGY HAS SIGNIFICANTLY RESHAPED ENVIRONMENTAL ASSESSMENTS--OFFERING ENHANCED INSIGHTS INTO FOREST HEALTH REFINED CARBON STOCK EVALUATIONS INFORMED FIRE RISK PREDICTIONS AND NEW BIODIVERSITY METRICS -- THE VEGETATION DOMAIN REMAINS LARGELY UNEXPLORED AT SCALES SIMULTANEOUSLY DETAILED AND SPATIALLY EXTENSIVE DUE TO THE COMPLEXITY OF NAVIGATING THESE ENVIRONMENTS. NO SYSTEM HAS YET BEEN BUILT THAT IS CAPABLE OF EFFECTIVELY EXPLORING THE VEGETATION DOMAIN.MODERN HIGH-RESOLUTION METHODOLOGIES NOTABLY TERRESTRIAL LIDAR SCANNING (TLS) OFFER SCIENTIFIC INSIGHTS BUT ARE NOT WITHOUT LIMITATIONS PRIMARILY IN LABOR EFFICIENCY AND THE SPATIAL EXTENT NEEDED FOR BROADSCALE FORESTRY ASSESSMENTS. RECOGNIZING THIS KNOWLEDGE GAP WE INITIATED PROJECT CLEARWING. THIS VENTURE AIMS TO CONCEPTUALIZE AND BRING TO FRUITION A SENSOR SUITE AND ASSOCIATED ALGORITHMS TO ENABLE AUTONOMOUS AND SAFE NAVIGATION OF UAVS THROUGH DENSELY FORESTED VEGETATION DOMAINS. THIS SYSTEM WILL BE ENGINEERED FOR: A) AUTONOMOUS NAVIGATION B) OBJECTIVE-OPTIMIZED EXPLORATIVE ROUTE PLANNING C) OBSTACLE DETECTION AND AVOIDANCE AND D) DATA COLLECTION WITHIN THESE VEGETATION DOMAINS. THE SENSORS WILL INCLUDE MOBILE LIDAR DEPTH CAMERAS AND OPTIONALLY RGB CAMERAS AND OTHER SENSORS AS DEEMED NECESSARY INTEGRATED WITH A COMMERCIAL OPEN-SOURCE UAV PLATFORM.AUTONOMOUS UAV PLANNING AND NAVIGATION IN FORESTS HAS SEEN SOME PROGRESS BUT PROJECTS TO DATE HAVE BEEN LIMITED TO RELATIVELY OPEN UNDERSTORIES (ESSENTIALLY EQUATING TO AVOIDING COLLISIONS WITH PILLARS). NO SYSTEM HAS DEMONSTRATED AN ABILITY TO NAVIGATE THE SMALL AND COMPLEX SPACES IN A FOREST. ONE CHALLENGE IS DETECTING THE SMALL-DIMENSIONAL OBJECTS SUCH AS TWIGS THAT CAN CAUSE CRASHES. DETECTING WIRES IS THE CLOSEST ANALOG12 BUT THIS IS STILL IN EARLY STAGES AND HAS NOT RECEIVED FOCUSED ATTENTION.THE EXPERIMENTAL TRAJECTORY OF PROJECT CLEARWING IS TWOFOLD. IT COMMENCES WITH LEVERAGING PLOTS IN ARIZONA PREVIOUSLY SCANNED USING TLS. THESE PLOTS FUNCTION AS A FOUNDATIONAL VALIDATION FRAMEWORK QUANTIFYING THE ACCURACY AND RELIABILITY OF THE UAV'S DATA ACQUISITION. THE EXPLORATION THEN EXPANDS BEYOND THE BOUNDARIES OF THE TLS MEASUREMENTS STRETCHING ACROSS 9-HA PLOTS WITH THE TLS PLOT AT THE CENTER. THIS MORE EXPANSIVE FORAY ALLOWS FOR DEMONSTRATING THE MEASUREMENT OF HIGH-RESOLUTION ABOVEGROUND STANDING BIOMASS DENSITY (AGB) AND DISCERNING HOW TREE ALLOMETRIES AND AGB VARY IN RESPONSE TO SMALL-SCALE ENVIRONMENTAL FACTORS. IT WILL ALSO ALLOW FOR DEMONSTRATING AN UNPRECEDENTED ASSESSMENT OF FOREST FIRE VULNERABILITY BY QUANTIFYING COARSE WOODY DEBRIS (CWD) HERBACEOUS LAYERS AND LADDER FUELS IN GREAT DETAIL ACROSS EXTENSIVE SPATIAL SCALES.RECENT RESEARCH ENDEAVORS AT NAU ENCOMPASSING GROUNDBREAKING WORK ON METHANE UPTAKE BY TREE BARK3 AND THE AMBITIOUS ARIZONA TREE STRESS EXPLORER AND ALERT SYSTEM4 FURTHER SOLIDIFY THE NEED AND TIMING FOR PROJECT CLEARWING. PI SHENKIN AN ECOLOGIST WITH A BACKGROUND IN ELECTRICAL ENGINEERING STUDIES THE INTERACTION BETWEEN FOREST MANAGEMENT AND RESILIENCE IN A CHANGING CLIMATE5-8 THE DETERMINANTS OF TREE SHAPE9-11 AND IS A LEADER IN THE FIELD OF EMPLOYING TLS-DERIVED 3D TREE MODELS TO IMPROVE UNDERSTANDING OF ECOSYSTEM PROCESSES SUCH AS WOODY RESPIRATION TREE MORTALITY AND CARBON STOCKS11-23. PRELIMINARY STRIDES WITH CS AND EE CAPSTONE TEAMS AT NAU DEMONSTRATE ADVANCEMENTS IN SOFTWARE DEVELOPMENT AND POWER DISTRIBUTION. CO-PI SANKEY'S CURRENT WORK FOCUSES ON TLS-BASED FOREST FUEL ESTIMATES AND UPSCALING THEM TO UAV-BASED AND SATELLITE IMAGE-DERIVED FUEL ESTIMATES IN AREAS EXPERIENCING DIFFERENT FIRE RETURN INTERVALS2425. FURTHERMORE CO-PI SANKEY EXAMINES FIRE AND THINNING IMPACTS ON FOREST CANOPY TEMPERATURE MOISTURE CONTENT AND EVAPOTRANSPIRATION USING UAV MULTISPECTRAL HYPERSPECTRAL LIDAR AND THERMAL SENSORS COMBINED WITH NASA'S ECOSTRESS SATELLITE ESTIMATES25-33. THE INTELLIGENT CONTROL SYSTEMS LAB DIRECTED BY CO-PI NGHIEM HAS EXPERIENCE IN DEVELOPING AND IMPLEMENTING ALGORITHMS FOR AND DEPLOYING AUTONOMOUS ROBOTS34-39. THE LAB HAS BEEN LEADING THE DEVELOPMENT DEPLOYMENT AND EXPERIMENTATION OF TERRESTRIAL ROVERS AND UAVS FOR ENVIRONMENTAL SENSING AND MONITORING IN A RESEARCH INFRASTRUCTURE. CO-PI SHAFER'S DYNAMIC AND ACTIVE SYSTEMS LAB HAS EXTENSIVE EXPERIENCE DEVELOPING AND DEPLOYING UAV SYSTEMS FOR FIELD USE INCLUDING DEVELOPING ROBOTIC HARDWARE SOFTWARE AND DATA ACQUISITION AND PROCESSING PAYLOADS. HIS LAB OWNS MULTIPLE PIECES OF EQUIPMENT USEFUL FOR UAV SYSTEM DEVELOPMENT INCLUDING ELECTRONICS AND SOLDERING EQUIPMENT 3D PRINTING CAPACITY CARBON MACHINING AND NEARBY OUTDOOR FACILITIES FOR UAV FIELD TESTING.THE IMPLICATIONS OF PROJECT CLEARWING ARE SIGNIFICANT. THE SYSTEM'S ABILITY TO PRODUCE HIGH-RESOLUTION 3D FOREST MODELS WILL SURPASS EXISTING TLS CAPABILITIES LARGELY DUE TO IT ENABLING THE UAV TO CLOSELY APPROACH INTRICATE FOREST STRUCTURES IMAGING IT FROM MULTIPLE ANGLES TO AVOID OCCLUSION AND TO OPERATE ACROSS EXTENSIVE SPATIAL SCALES. MOREOVER INCORPORATING ADDITIONAL SENSORS SUCH AS THOSE FOR TEMPERATURE HUMIDITY OR LIGHT COULD CHARACTERIZE FOREST MICROENVIRONMENTS THROUGHOUT THE VEGETATION DOMAIN ON NOVEL SCALES40. THIS DATA IN TURN HOLDS THE POTENTIAL TO REVOLUTIONIZE FORESTRY OPTIMIZE TIMBER HARVESTING OPERATIONS ENHANCE FOREST MANAGEMENT STRATEGIES REFINE CARBON MAPPING AND ECOSYSTEM MODELS AND CALIBRATE/VALIDATE SATELLITE DATA PRODUCTS TO HIGHER STANDARDS.