Airborne Lidar Sensors - Professional Surveyor Magazine

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Airborne Lidar Sensors Airborne Lidar Sensors This is GIM International’s third product review on airborne Lidar sensors. The second was published in February 2007 and the first under the title ‘Airborne Laser-scanners’ in May 2004. A irborne Lidar has matured to an accurate technology for the highly automated capturing of terrain data  through xyz point clouds. “Mature” This is our third product review onmeans airbornethat  Lidarimprovesensors. are noin longer major The secondments was published Februaryfounded 2007 and on the first technological  breakthroughs, but are incremental. under the title ‘Airborne Laser-scanners’ in May 2004. Lately the steps comprise full waveform digitisation, multiple pulses inhas air, and increased accuracy resultAirborne Lidar matured to an accurate technology ing from enhanced GNSS positioning and INS for the highly automated capturing of terrain data attitudethrough determination. xyz point clouds. “Mature” means that Manufacturers coming twotechnological opposite improvements are noare longer foundedfrom on major directions:  system building versus service breakthroughs, but are incremental. Lately the stepsprovision. System builders include Leica Geosystems comprise full waveform digitisation, multiple pulses in and air, Optech Inc., but most conspicuous is Riegl. Until late and increased accuracy resulting from enhanced GNSS 2006, the latter wasattitude a manufacturer for manufacturpositioning and INS determination. ers only, offering airborne applicaManufacturers are ‘laser comingsensors for from two opposite directions: tions but not complete airborne Lidar systems. But system building versus service provision. System builders in the 2007 survey, Riegl presented its  full-fledged include Leica Geosystems and Optech Inc., but most systems LMS-S560 and LMS-Q560.  On the service conspicuous is Riegl. Until late 2006, the latter was a provision side is Fugro, listed in the 2007 survey. Like manufacturer for manufacturers only, offering ‘laser sensors TopEye and Terrapoint, Fugro developed its own infor airborne applications but not complete airborne Lidar house system, Flimap. “e system has been regular and systems,’ as our 2004 survey notes to explain the many N/As is designed for corridor mapping using helicopters. in the columns. But in the 2007 survey, Riegl presented its When manufacturers cross the line, differencfull-fledged systems LMS-S560 and LMS-Q560. es become more  diffuse. German company ToOn the service provision side is Fugro, listed in the 2007 poSys combines manufacturing with self-executsurvey. Like TopEye and Terrapoint, Fugro developed its own ed surveys and considers this dual role as a base in-house system, Flimap. The system has been regular and is for expertise. Product features are quite similar designed for corridor mapping using helicopters. to those of the Riegl systems even in name: LMSQ560 vs Harrier 56 and LMS-Q680 vs Harrier 68; When manufacturers cross the line, differences become more indeed, the core of the TopoSys systems are Riegl diffuse. German company TopoSys combines manufacturing sensors. “is is also true for German firm IGI’s airwith self-executed surveys and considers this dual role as a borne Lidar terrain mapping system LiteMapper, base for expertise. Product features are quite similar to those which was listed in the 2007 survey. TopEye, listof in theboth Riegl the systems even in 2007 name:surveys, LMS-Q560 vs Harrier 56 ed 2004 and was initially and LMS-Q680 vs Harrier 68; indeed, the core of the both a system builder and a service provider. With TopoSys systems are Rieglcompany sensors. ThisSaab, is alsoTopEye true for beits origins in Swedish German firm IGI’s airborne Lidar terrain mapping system came part of the Blom  Group - which uses the LiteMapper, which was listed in the 2007 survey. TopEye, technology for geodata collection - in July 2005. listed in bothSaab the 2004 and 2007 surveys, was initially Another development is a system forboth hy- a system builder and a service provider. With its origins in drographic and  topographic surveys. In 2002, Swedish company Saab, for TopEye became part theformer Blom Saab sold the rights the system to of tree Group which uses the technology for geodata collection - in employees who launched Airborne Hydrography. July 2005. “e company is listed in our product overview for the first time, with its Dragon Eye topographic LiAnother Saaband development is a system for hydrographic and dar  sensor Hawk Eye II bathymetry and totopographic surveys. In 2002, Saab sold the rights for the pography airborne laser system. system to tree former employees who launched Airborne The company is listed our product overview HHydrography. ank Key is contributing editor of ourinsister publicaiton, for the first GIM time,International. with its Dragon Eye topographic Lidar sensor and Hawk Eye II bathymetry and topography airborne Professional Surveyor Magazine • May 2009 laser system. 16 N/A = Not Applicable = No information received Manufacturer Airborne Hydrography AB type/name of software Dragon Eye - Topographic Lidar Sensor data of introduction/last update October 2008 Dimensions weight [kg] & size [cm] of laser system 25kg; 45 x 45 x 25 cm weight [kg] & size [cm] of control rack included in laser system power requirements < 15 A at 28V Laser Pulse Characteristics wavelength [nm] 1,000 nm pulse length [ns] < 5 ns beam divergence (across/along tr.) [mrad] 1 mrad (0.5 mrad optional) first/last pulse (Y/N) Y multiple pulses in air (Y/N) Y type/class laser Class 4 eyesafe range [m] < 100 m Recording Methodology scanning method Palmer scanner rotation speed of mirror (scan frequency) Typical 3000 RPM pulse frequency (min-max) [Hz] 50,000-500,000 Hz max. scan angle [deg] ±20 deg standard. Other as option. max. # of recorded echoes/pulse Typical 4 echoes/pulse pulse sampling frequency 1,28 GHz pulse detection method (which part of reflected pulse) Proprietary recording of return signal intensity [y(bits)/n] Y (12 bits raw, 16 bits enhanced) Positioning System GPS system Several options GPS precision planimetric/height (2 sigma) [cm] Pending on GPS option selected INS system Several options available INS precision (roll/pitch/heading) [deg] Pending on INS option selected GPS/INS postprocessing software Pending on GPS/INS option selected Precision and Resolution Pointing precision (roll/pitch/heading) [deg] <0,01 deg Range precision (2 sigma) [cm] < 3 cm Elevation precision at 1km (2 sigma) [cm] Pending on GPS / INS option selected Overall planimetric precision (2 sigma) [cm] Pending on GPS / INS option selected Max. # of points/m2 Typical 50 /m2 (at 150 m, 300 kHz, 20 m/s) Along track point spacing [m] (flight alt. 1,000 m) Typical 0,4 m (at 500 m, 40 m/s) Across track point spacing [m] (typical flying speed of 150 km/h) Typical 0,5 m (at 500 m 200 kHz) Other System Parts Cameras Options 16 to 40 MPix available Data Storage Facilities Solid State Disc, Removable Power equipment 110/220 V ground power supply available Operation Characteristics typical platform (fixed wing or helicopter) Helicopter or Small fixed wing flying heights (min/typical/max) [m] 100m / 500m / 1000 m max. acquisition duration [hrs] Carrier limited. System limit 8+ hours air temperature (min-max) [°C] 0 to 35°C air humidity (min-max) [%] 0 to 90% mission planning software Operator Console; import from other software postprocessing software Land Survey Studio proven applications Flight tests ongoing remarks System optimized for low altitude, high accuracy, high data density applications. Each object on ground illuminated from 2 sides. BY MATHIAS LEMMENS, SENIOR EDITOR, GIM INTERNATIONAL PRODUCT OVERVIEW Airborne Hydrography AB Leica Geosystems Optech Incorporated Optech Incorporated Hawk Eye II - Bathymetric and Topographic Lidar system ALS60 Airborne Laser Scanner ALTM Gemini ALTM Orion 2006/2008 September 2008 October 2006 October 2008 95kg; 121 x 50 x 62 cm 38.5kg; 60 L x 37 W x 27 H cm 23.4kg; 26 x 19 x 57 cm 27kg; 34 x 34 x 26 cm 65kg; 60 x 36 x 70 cm 45.0kg; 62 D x 45 W x 36 H cm 53.2kg; 65 x 59 x 49 cm N/A < 1.3 kW 980 W peak at 28 VDC nominal 28 VDC 35 A (maximum) 28 VDC 15 A (maximum) 532 nm bathy , 1,064 nm topo 1064 nm 1,064 nm 1,064 nm 5 ns 5 ns 7 ns <7 ns 11 mrad typical (Optional 2-12 mrad adjustable) 0.22 mr at 1/e^2 (0.15 mr at 1/e) 0.8, 0.25, 0.15 I/e 0.25 1/e Y Yes (1st, 2nd, 3rd, last) Y Y N Yes (2PiA) Y N Class 4 Class 4 Class 4 (FDA 21 CFR) Class 4 (FDA 21 CFR) < 150 m 39 m single pulse, unaided eye at 200 kHz 80 m + 200 m, variable 2-axis gimbal 250 mm diameter mirror oscillating mirror Oscillating mirror Oscillating mirror 13 Hz scan rate. 2D tracking optimization up to 100 Hz 70 Hz 100 Hz 4,000 Hz bathymetric, 64,000 Hz topographic 20,000 - 200,000 Hz 167,000 Hz 150,000 Hz ±25 deg. 75 deg. full angle 50 deg 50 deg Bathy full waveform, topo 4 echos per pulse 4 (1st, 2nd, 3rd, last) 4 ranges 4 ranges 1 GHz N/A Proprietary Leading edge discriminator at 50% peak Leading edge Leading edge Y (8 bits bathymetric) Y (8 bits after AGC and laser output adjustment) Y (12 bits) Y (12 bits) Applanix Pos AV 410 or 510 NovAtel, L1/L2+GLONASS+SBAS, 54 channels, 20 Hz update raw Trimble, 72 channel, dual-frequency, GPS, GNSS Trimble, 72 channel, dual-frequency, GPS, GNSS < 60 cm / < 10 cm (Post Processed, 2 sigma) ~10 cm, depending on constellation configuration 0.05 cm 0.05 cm Applanix Pos Av 410 or 510 Leica IPAS20 DUS5 (200 Hz), NUS5 (500 Hz), CUS6 (200 Hz) POS 610, 200 Hz POS 510, 200 Hz 0,01 deg (Post processed, 2 sigma) 0.005 deg RP/0.008 deg H (DUS5/NUS5), 0.0025 deg RP/0.005 deg H (CUS6) 0.0025/0.0025/0.005 deg 0.005/0.005/0.008 deg PosPAC GrafNav + IPAS Pro POSPAC MMS POSPAC MMS < 0,03 deg not normally specified, ~0.006 degrees (R/P), ~0.009 degrees (H) 0.0025/0.0025/0.005 deg 0.005/0.005/0.008 deg Bathy < 50 cm, Topo < 30 cm (Typical conditions, 2 sigma) not normally specified, ~3-4 cm 3 cm 2 cm Bathy < 50 cm, Topo < 30 cm ( Typical conditions, 2 sigma) 14 - 16 cm, assuming 5 cm GPS error, 2 sigma at 1000 m AGL < 10 cm <10 cm Bathy < 5 m, Topo < 1m (Typical conditions, 2 sigma) 20 - 26 cm, assuming 5 cm GPS error, 2 sigma at 1000 m AGL 1/11000 1/5500 Bathymetric 1 point/m2, topographic 10 points/m2 91 points/m2 at 150 km/h, 200 m AGL, 15 degree FOV Bathy 1,9 m / Topo 0,5 m (at 300m, 75 m/s) 0.21 m at nadir at 150 km/h, depending on FOV 0.36 m 0.42 m Bathy 1,9 m / Topo 0,5 m (at 300m, 75 m/s) 0.29 at15 deg FOV, 0.62 m at 63 deg FOV, both at 150 km/h and 1000 m AGL, square point spacing at nadir 0.30 m 0.43 m Optional 2 or 16 Mpix Intenal 1280 x 1024 webcam standard, external 39 MP RCD105 Applanix DSS 439, 422; Rollei AIC 39 Mpixel optional Applanix DSS 439, 422; Rollei AIC 39 Mpixel Raided harddrives, removable removable 500 GB drive External removable hard disk, min 146 Gb Fixed internal and/or optional external removable hard disk, min 146 Gb 110 / 220 V ground power supply available PS56 ground power supply Internal Internal; optional external Fixed wing both Twin engine fixed-wing, helicopter UAV, fixed wing, helicopter 250 to 500 m 200 to 5000 m AGL 80m / 2000 m / 4000m 200m / 1000m / 2500m Carrier limited. System limit 8+ hours 18 hours at maximum pulse rate Unlimited Unlimited 0 to 35°C 0 to 40°C cabin-side temperature -10°C to +35°C -10° C to +40°C 0 to 90% 0 to 95%, non-condensing 0 to 95%, non-condensing 0 to 95%, non-condensing Operator Console; import from other software Leica AeroPlan (system setup planning), Leica FPES (flight planning) ALTM NAV ALTM NAV Coastal Survey Studio Leica ALS Post Processor (point cloud generation), Leica LCam Viewer (webcam image viewer) DASHMap DASHMap Many surveys around the world mapping of flood plains, territories, power lines, pipelines, railways Corridor mapping, wide-area survey, urban mapping, etc. and roads; city modelling; foresty; hydrology; biomass determination Corridor mapping, wide-area survey, urban mapping, etc. Bathymetry (down to 50m) and topography simultaneausly. Roll, pitch, yaw and off-track scanning compensation. Available also in Corridor Mapper model. All specifications identical, except maximum flying height limited to 1000 m AGL World’s smallest full-system Lidar sensor (1.0 cu ft.; 0.03m3). High density and accuracy independent of pulse rate. Global 24/7 technical support. Continuous Multipulse technology with complete coverage throughout entire operating range (i.e. no blind zones or range gates to avoid). Global 24/7 technical support. Professional Surveyor Magazine • May 2009 N/A = Not Applicable = No information received Manufacturer RIEGL RIEGL RIEGL TopoSys GmbH type/name of software RIEGL VQ-480 RIEGL LMS-Q560 RIEGL LMS-Q680 Harrier 56/G4 data of introduction/last update October 2008 last update January 2008 introduction Q1 2009 February 2008 / June 2008 weight [kg] & size [cm] of laser system 11.5 kg; 34.5 x dia. 18 cm 16kg; 42 x 21.2 x 22.8 cm 17.5kg; 48 x 21.2 x 23 cm 42kg; 64 x 30 x 48 cm weight [kg] & size [cm] of control rack N/A N/A N/A 42kg; 54 x 50 x 44 cm power requirements 65 W 120 W 170 W 28 V DC, 20 A max. wavelength [nm] 1,550 nm 1,550 nm 1,550 nm 1,550 nm pulse length [ns] < 4ns < 4ns < 4 ns < 4ns beam divergence (across/along tr.) [mrad] 0.3 mrad 0.3 mrad 0.4 mrad 0.3 mrad first/last pulse (Y/N) Y Y Y Y multiple pulses in air (Y/N) N N Y N type/class laser Class 1 Class 1 Class 3R Class 1 eyesafe range [m] 0m 0m 50 m 0m scanning method Rotating multi-facet mirror Rotating multi-facet mirror Rotating multi-facet mirror Rotating multi-facet mirror rotation speed of mirror (scan frequency) 10 - 100 Hz 10 - 160 Hz 10 - 200 Hz 10 - 160 Hz pulse frequency (min-max) [Hz] 50,000 - 200,000 Hz 50,000 - 240,000 Hz 80,000 - 240,000 Hz 50,000 - 240,000 Hz max. scan angle [deg] 60 deg 60 deg 60 deg 60 deg max. # of recorded echoes/pulse practically unlimited practically unlimited practically unlimited Practically unlimited 1 GHz 1 GHz 1 GHz Full Waveform processing Full Waveform processing Full Waveform processing Y (16 bits) Y (16 bits) Y (16 bits) Dimensions Laser Pulse Characteristics Recording Methodology pulse sampling frequency pulse detection method (which part of reflected pulse) Online waveform analysis recording of return signal intensity [y(bits)/n] Y (16 bits) Positioning System GPS system Interface to any GPS receiver, e.g. Novatel, Trimble, Javad, 12 channels, dual frequency Interface to any GPS receiver, e.g. Novatel, Interface to any GPS receiver, e.g. Novatel, Applanix POS/AV 410 Trimble, Javad, 12 channels, dual frequency Trimble, Javad, 12 channels, dual frequency GPS precision planimetric/height (2 sigma) [cm] 5 - 30 cm rms 5 - 30 cm rms 5 - 30 cm rms 5 - 30 cm rms INS system AEROcontrol | POS AV 410, 510 256 Hz | 200 Hz AEROcontrol | POS AV 510 256 Hz | 200 Hz AEROcontrol | POS AV 510 256 Hz | 200 Hz Applanix POS/AV 410 INS precision (roll/pitch/heading) [deg] 0.004 / 0.004 / 0.01 | 0.005 / 0.005 / 0.008 0.004 / 0.004 / 0.01 | 0.005 / 0.005 / 0.008 0.004 / 0.004 / 0.01 | 0.005 / 0.005 / 0.008 0.005 / 0.005 / 0.008 GPS/INS postprocessing software AEROoffice AEROoffice AEROoffice POSPac MMS 5.10 | POSPac | POSPac | POSPac Precision and Resolution Pointing precision (roll/pitch/heading) [deg] limited by INS/GPS accuracy limited by INS/GPS accuracy limited by INS/GPS accuracy Limited by INS/GPS accuracy Range precision (2 sigma) [cm] 5 cm 2 cm 4 cm 2 cm Elevation precision at 1km (2 sigma) [cm] < 15 cm, depending on DGPS accuracy < 15 cm, depending on DGPS accuracy < 15 cm, depending on DGPS accuracy < 15 cm, depending on DGPS accuracy Overall planimetric precision (2 sigma) [cm] < 10 cm, depending on DGPS accuracy < 10 cm, depending on DGPS accuracy < 10 cm, depending on DGPS accuracy < 10 cm, depending on DGPS accuracy Max. # of points/m2 50 at 50 km/h / 150 m / 60° (helicopter) 4 at 200 km/h / 500 m / 60° (fixed-wing) 66 at 50 km/h / 150 m / 60° (helicopter) 5 at 200 km/h / 500 m / 60° (fixed-wing) 4 at 200 km/h / 500 m / 60° (fixedwing) 66 at 50 km/h / 150 m / 60° (helicopter) Along track point spacing [m] (flight alt. 1,000m) 0.42 m at 10 scans/s and 50 kHz PF 0.16 m at 10 scans/s and 100 kHz PF 0.07 m at 10 scans/s and 240 kHz PF 0.16 m at 10 scans/s and 100 kHz PF Across track point spacing [m] (typical flying speed op 150 km/h) 0.42 m at 100 scans/s 0.26 m at 160 scans/s 0.2 m at 200 scans/s 0.26 m at 160 scans/s Cameras DigiCAM /Applanix DSS or similar DigiCAM /Applanix DSS or similar DigiCAM /Applanix DSS or similar Integrated medium format frame camera (Rollei or DSS). Optional line scanner camera Data Storage Facilities N/A Removable hard-disks, 2 x 500 Gbytes Removable hard-disks, 2 x 500 Gbytes Removable hard-disks, 2 x 500 Gb Power equipment N/A N/A N/A UPS typical platform (fixed wing or helicopter) helicopter both both both flying heights (min/typical/max) [m] 10m / 450m / 800m AGL 30m / 800m / 1500m AGL 50m / 1600m / 2500m AGL 30m / 800m / 1500m AGL max. acquisition duration [hrs] N/A 8 hours 8 hours 8 hours, although HDDs are changeable during flight time air temperature (min-max) [°C] -10 to 40°C 0 to 40°C 0 to 40°C 0 to 40°C air humidity (min-max) [%] 80% (at or below 31°C) 80% (at or below 31°C) 80% (at or below 31°C) 80% (at or below 31°C) mission planning software e.g. WinMP, TrackAir or similar e.g. WinMP, TrackAir or similar e.g. WinMP, TrackAir or similar Track’Air postprocessing software RiPROCESS , RiWorld RiAnalyse, RiPROCESS , RiWorld RiAnalyse, RiPROCESS , RiWorld RiAnalyze, TopPIT full laser and imagery suite proven applications Corridor mapping, UAV surveying All typical airborne Lidar projects All typical airborne Lidar projects All typical airborne Lidar projects remarks Echo digitization and online waveform analysis; compact and lightweight Access to detailed target parameters by full Access to detailed target parameters by waveform processing full waveform processing. High operating altitudes Other System Parts Operation Characteristics 18 | F E BR U A RY 2 0 0 9 | Full waveform processing. Fully tight complete integrated system INTERNATIONAL Professional Surveyor Magazine • May 2009 PRODUCT OVERVIEW TopoSys GmbH TopoSys GmbH Harrier 68/G1 Falcon II Q1 2009 2000 / 2008 (Falcon Iid) N/A at the moment 41kg; 39 x 47.5 x 45 cm N/A at the moment 54kg; 47 x 48 x 58 cm 28 V DC, 22 A max. 28 V DC, 15 A max. 1,550 nm 1,560 nm < 4 ns 5 ns 0.4 mrad 1 mrad Y Y Y N Class 3R Class 4 50 m > 0.5 m Rotating multi-facet mirror Fibre Laser Scanner 10 - 200 Hz 648 Hz 80,000 - 240,000 Hz 83,000 Hz 60 deg 214.6 deg Practically unlimited 9 return echoes 1 GHz Full Waveform processing Y (16 bits) Y (12 bits) Applanix POS/AV 410 Applanix POS/AV 410 5 - 30 cm rms 5 - 30 cm rms Applanix POS/AV 410 Applanix POS/AV 410 0.005 / 0.005 / 0.008 0.005 / 0.005 / 0.008 POSPac MMS 5.10 POSPac MMS 5.10 Limited by INS/GPS accuracy Limited by INS/GPS accuracy 4 cm < 1 cm < 15 cm, depending on DGPS accuracy < 15 cm, depending on DGPS accuracy < 10 cm, depending on DGPS accuracy < 10 cm, depending on DGPS accuracy 5 at 200 km/h / 500 m / 60° (fixed-wing) 12 at 200 km/h / 500 m / 14.3° (fixedwing) 0.07 m at 10 scans/s and 240 kHz PF 0.06 m 0.2 m at 200 scans/s 1.96 m Integrated medium format frame camera Integrated line scanner camera (Rollei or DSS). Optional line scanner camera Removable hard-disks, 2 x 500 Gb Removable hard-disks UPS UPS both both 50m / 1600m / 2500m AGL 30m / 900m / 1600m 8 hours, although HDDs are changeable during flight time HDDs are changeable during flight time 0 to 40°C 0 to 40°C 80% (at or below 31°C) 90% Track’Air Track’Air RiAnalyze, TopPIT full laser and imagery suite TopPIT full laser and imagery suite All typical airborne Lidar projects All typical airborne Lidar projects Full waveform processing. Fully tight Fully tight complete integrated; line complete integrated system. High operating scanner camera. altitudes. F E B R U A RY 2 0 0 9 | Professional Surveyor Magazine • May 2009 INTERNATIONAL | 19