280 likes | 452 Views
Procedures for FOD Detection System Performance Assessments. Radar-Based and Dual Sensor Systems. Beth Woodworth Edwin Herricks University of Illinois. Introduction. I will be talking today about two performance assessment efforts.
E N D
Procedures for FOD Detection System Performance Assessments Radar-Based and Dual Sensor Systems Beth Woodworth Edwin Herricks University of Illinois
Introduction • I will be talking today about two performance assessment efforts. • The initial effort began in 2004 and was completed with assessment of an installed system on a runway at PVD in 2008. • The second began in 2007 and was completed in 2009.
Sensors Evaluated • Qinetiq TarsierTM • Radar based system • Installed at PVD • Xsight FODetectTM • Hybrid system • Installed at BOS
Testing of QinetiQ TarsierTM at PVD • 94Ghz radar • Detects FOD at ranges up to 1 km • 2 sensor units placed on towers scanned Runway 5/23 at PVD • Primary performance criterion was a standard -20dBm2 target at a range of 1km
Testing of FODetectTM at BOS • 74GHz radar and video camera with image processing • Sensors replaced edge lights • Partial installation at BOS • Sensors covered 550 ft on Runway 15R • 10 surface detection units (SDUs) – 5 SDUs on each side of the runway • Each sensor covered approximately 75ft x 200ft • Primary performance criterion detection of 0.8 in (2 cm) object
General Assessment Protocol • Testing scheduled over approximately 12-month period to capture varied weather conditions • PVD – June 2007- March 2008 • BOS – June 2008 - March 2009 • Targets selected to challenge each of the systems and included • Different sizes • Different shapes • Different materials • Different hazard potentials
Detecting a Target • Radar • Reflectivity – energy returned to sensor • “Complex Scatterers” – most FOD has a variety of edges which have different likelihoods of being detected. • Electro-Optical • Background • Item surface conditions • Color, Flat/Glossy • Illumination – • Lighting and shadow
Overall Goals of Testing • Calibration – Standard Target Testing • Uses items of known detection characteristics • Provides information on system reliability and robustness • Performance • Group of FOD items with different hazard potentials • Repeatedly placed at known locations in defined positions • Blind • Random placement and actual and simulated FOD items • This test most represents typical detection needs at an airport • Challenges system to detect a diverse and unpredictable set of items.
General Methods • Safety – • Because assessments were conducted at operational airports, safety considerations were paramount. • Personnel were trained and briefed regularly by airport operations personnel. • Although runways were closed, safety areas were identified and drills held so that all assessment personnel were aware of their environment. • Rigorous accounting was made of all experimental FOD taken on the airport.
General Methods • FOD log – Over 1000 items placed and retrieved! • all items were written in a log before proceeding to the runway • after return and often during the testing the log was checked again the items in the box • FOD box – items put in boxes with dividers in order to be easily and quickly counted • Marking • Used for calibration and performance testing • Small, nearly invisible UV marks were placed on the runway • UV lights used to find markings • Locations were surveyed using a differential GPS accurate to millimeters in the X/Y plane • Surveyed locations were compared with locations provided for each detection by each technology
General Methods • Radar • Does NOT depend on illumination • All assessment campaigns at PVD were performed during normal 12 pm to 5 am runway closures • Electro-Optical • Did depend on illumination. • Testing at BOS was on Runway 15R which saw limited use allowing testing at different times. • Tests were performed at BOS during the day, at night, and at dawn and dusk to capture a range of lighting conditions.
Calibration – Standard Target Testing • GOAL = confirm detection performance using objects with defined detection characteristics • Targets selected based on technology • Metal cylinders 3in X 4.5in 1.25in with a nominal reflectivity of 0dBm2 (Large) • Metal cylinders 2in X 2.5in with a nominal reflectivity of -10dBm2 (Medium) • Metal cylinders 1.5in x 1.25in with a nominal reflectivity of -20dBm2 (Small) • Metal 2in spheres • Colored PVC cylinders 1.5in X 1.25in colored grey, white and black
Calibration Targets • Metal cylinders • 1.5in x 1.25in • -20dBm2 • (Small) • Metal cylinders • 2in X 2.5in • -10dBm2 (Medium) • Metal cylinders • 3in X 4.5in 1.25in • 0dBm2 (Large) • Metal spheres 2in Colored PVC cylinders 1.5in X 1.25in
Calibration- Standard Target Testing for TarsierTM • 4 types of metal targets • 6 transects along full length of the runway • Transects 2, 3, and 4 within 1km of both radars • Transects 1, 5, and 6 used for system assessments
Calibration for FODetectTM • Metal cylinders 1.5in x 1.25in tested the radar portion of the sensor • 3 colors of PVC cylinders (white, grey, black) and small metal cylinder • Targets placed at varying distances from sensor in a test rectangle (approx. 150ft x 70ft) • Targets placed to test the system and a single sensor • Standard target array included 1 metal, 1 white, 1 grey, and 1 black cylinder • Groups of targets oriented differently
Performance Testing • Items not selected based on sensor type as with calibration testing • Used examples of common items found at airports • Selection of items based on frequency of occurrence and hazard potential • Calibration items also used during performance testing • Items placed in know positions at specific angles
Table of Standard FOD Items Used in Performance Assessments This table contains the items selected by CEAT
Performance Testing Methods at PVD • 6 arrays related to standard target transects • In array 5x5 grid established, approximately 25ft between items • 23 targets total per array (no items set on runway lights) • Position of items varied between campaigns (random selection of location achieved in test planning); items in the same position in all arrays in any single campaign. • All items rotated 45 degrees after each scan to cover 8 cardinal points of the compass
Performance Testing Methods at BOS • Line established midway between the centerline and the edge line • 5 identical performance items placed at equal distances on this line across the length of test rectangle • Items rotated so detections at 0, 45, and 90 degrees relative center line recorded
Blind Testing Blind Testing Grid at PVD • Used actual FOD items collected from runways • Range of sizes, materials, colors • Over 100 items in collection • 30 items randomly selected for each campaign • Placement locations chosen at random from a grid • Items dropped or tossed so the orientation was random • Up to 10 items used at one time.
Blind Testing Grid of Locations at BOS Typical Grouping of FOD Blind Items
Inclement Weather Testing • Objective to evaluate sensor performance in variable weather conditions • Opportunistic based on long term plan, but scheduled adjusted to coincide with storm events. • Access to the runways in snow was impossible so assessments performed just after snow emergency conditions
Inclement Weather Assessment - Rain • PVD - TarsierTM radar system • October 2007 • Calibration targets were deployed as a rain squall moved across the runway • BOS – FODetectTM hybrid system • March 2008 • One light rain event at dusk
Inclement Weather Assessment - Snow • PVD – TarsierTM radar system • Assessments after 2 snow events • Jan. 24, 2008 – flurries but no accumulation • Feb. 12, 2008 – snow changing to sleet • Time for placement and retrieval were limited due to needs to clear the runway
Inclement Weather Assessment - Snow • BOS – FODetectTM hybrid system • Winter Storm Jan. 7-12 – • Weather Conditions: • rain, freezing rain, freezing drizzle, mist, ice pellets, fog, snow • Totaling 2.1in of wet precipitation • Testing took place on Jan 8, 9, and 13, 2009 • Testing on Jan. 29 and 30 after snow events as well
Summary • 2 systems – radar and hybrid • Assessments performed at PVD and BOS • Assessments took place in variable weather conditions • General protocol – calibration, performance, blind – consistent for all FOD detection system types • Actual procedures were adapted to each senor and adjusted for runway availability • Targets were selected based on • the performance claims of manufacturers • related to sensor characteristics and performance parameters