Presentation is loading. Please wait.

Presentation is loading. Please wait.

Www.riegl.com High-Speed High-Density Data Acquisition in Airborne Laser Scanning Applications INTERGEO September 2011, Nürnberg Peter Rieger Andreas Ullrich.

Similar presentations


Presentation on theme: "Www.riegl.com High-Speed High-Density Data Acquisition in Airborne Laser Scanning Applications INTERGEO September 2011, Nürnberg Peter Rieger Andreas Ullrich."— Presentation transcript:

1 www.riegl.com High-Speed High-Density Data Acquisition in Airborne Laser Scanning Applications INTERGEO September 2011, Nürnberg Peter Rieger Andreas Ullrich RIEGL LMS GmbH

2 www.riegl.com RIEGL Laser Measurement Systems Contents: ● Range ambiguities in time-of-flight measurements ● Known measures in resolving or avoiding range ambiguities ● Advantages and disadvantages ● Introduction to RIEGL’s novel approach

3 Airborne laser scanning is a rapid, highly accurate and efficient method of capturing 3D data of large areas. for planes: LMS-Q680i / LMS-Q560 Multiple-Time-Around (MTA) Processing (LMS-Q680i) Full Waveform Analysis for an unlimited number of target echoes operating flight altitude up to 5,000 / 3,300 ft AGL Laser PRR 400 / 240 kHz for helicopters: NEW RIEGL VQ-580 optimized for glacier and snow measurements RIEGL VQ-480 / VQ-380 echo digitization and Online Waveform Processing multiple target capability operating flight altitude up to 2,500 / 1,800 ft AGL Airborne Laser Scanning www.riegl.com

4 NEW RIEGL NP680i Highly compact, flexible and efficient turnkey ALS solution, fully EASA certified, comprising LMS-Q680i, DR560-RD, ALS software, INS/GNSS unit, and FMS, smoothly integrated into the "Universal Nose" of the Diamond twin-engine plane DA42 MPP. Airborne Laser Scanning www.riegl.com

5 Principle of time-of-flight measurements www.riegl.com Amplitude TmTm TnTn T m+1 SmSm EnEn S m+1 Time

6 Definition of „Multiple-Time-Around“ from the “IEEE Standard Radar Definitions, IEEE Std 686-1997 (1998)”: www.riegl.com

7 MTA Zone 1 Amplitude T m-3 T n-3 T m-2 T n-2 T m-1 T n-1 TmTm TnTn T m+1 S m-3 S m-2 S m-1 SmSm E n-3 E n-2 E n-1 EnEn S m+1 Time r m,MTA1 r m-1,MTA1 r m-2,MTA1 r m-3,MTA1 MTA Zone 1: www.riegl.com

8 MTA Zone 2 Amplitude T m-3 T n-3 T m-2 T n-2 T m-1 T n-1 TmTm TnTn T m+1 S m-3 S m-2 S m-1 SmSm E n-3 E n-2 E n-1 EnEn S m+1 Time r m-1,MTA2 r m-2,MTA2 r m-3,MTA2 MTA Zone 2: www.riegl.com

9 MTA Zone 3 Amplitude T m-3 T n-3 T m-2 T n-2 T m-1 T n-1 TmTm TnTn T m+1 S m-3 S m-2 S m-1 SmSm E n-3 E n-2 E n-1 EnEn S m+1 Time MTA Zone 3: r m-2,MTA3 r m-3,MTA3 r m-4,MTA3 www.riegl.com

10 MTA Zone 4 Amplitude T m-3 T n-3 T m-2 T n-2 T m-1 T n-1 TmTm TnTn T m+1 S m-3 S m-2 S m-1 SmSm E n-3 E n-2 E n-1 EnEn S m+1 Time MTA Zone 4: r m-3,MTA4 r m-4,MTA4 r m-5,MTA4 www.riegl.com

11 MTA Zone 1, 2, 3 or 4 ? Amplitude T m-3 T n-3 T m-2 T n-2 T m-1 T n-1 TmTm TnTn T m+1 S m-3 S m-2 S m-1 SmSm E n-3 E n-2 E n-1 EnEn S m+1 Time r m,MTA1 r m-1,MTA2 r m-2,MTA3 r m-3,MTA4 ? MTA 1 MTA 2 MTA 4 MTA 3 www.riegl.com

12 Maximum unambiguous range vs. pulse repetition rate R u =375m @ 400kHz x Maximum unambiguous measurement range R u [m] Pulse repetition rate [kHz] www.riegl.com

13 Known methods in avoiding range ambiguities: ● careful choice of operating altitudes ● Spatial multiplexing:  2 x RIEGL LMS-Q680i ● Wavelength multiplexing: RIEGL VQ-820-G (532nm), RIEGL VQ-580 (1064nm) Known methods in resolving range ambiguities: ● Spatial analysis based on known distance (RiANALYZE) www.riegl.com Methods in avoiding or resolving range ambiguities

14 Avoiding range ambiguities in flight planning MTA zone 1 MTA zone 2 MTA zone 3 www.riegl.com

15 Avoiding range ambiguities in flight planning www.riegl.com

16 Spatial Multiplexing typ. > 1 deg deam divergence typ. < 0.5 mrad Spatial separation by scanner orientationSpatial separation by mirror synchronization 1 PPS typ. > 10 deg www.riegl.com

17 Wavelength multiplexing Wavelength multiplex by using 2+ wavelengths 1550 nm1064nm532 nm VQ-820GVQ-580Q-680i www.riegl.com

18 Resolving range ambiguities by spatial analysis www.riegl.com

19 Advantages and Disadvantages MethodAdvantagesDisadvantages Flight Planning Complex and dangerous in difficult terrain Spatial multiplexing Overall pulse repetition rate doubled Doubling sales for manufacturer +1 scanner → only +1R u Higher investment for customer Irregular point pattern Complex system Wavelength multiplexing Additional attributes for target classification, e.g., vegetation indices Spatial data analysis Algorithms adaptable to application Tuning of algorithms if neccessary apriori knowledge of terrain required www.riegl.com

20 τ = PRR -1 Δt m+1 τ Δt m+2 τ Δt m+3 τ Δt m+4 τ = PRR -1 Δt m+1 τ Δt m+2 τ Δt m+3 τ Δt m+4 SmSm S m+1 S m+2 S m+3 EnEn E n+1 E n+2 TmTm TnTn T m+1 T n+1 T m+2 T n+2 E n+3 T m+3 T n+3 S m+4 T m+4 New approach, Step 1: Variation of pulse repetition intervals Amplitude Time r m,MTA2 = r true r m+1,MTA2 = r true r m+2,MTA2 =r true r m,MTA1 r m+1,MTA1 r m+2,MTA1 r m+3,MTA1 www.riegl.com

21 New approach, Step 2: Analysis of the influence of PRI jitter www.riegl.com

22 RiMTA RIEGL LMS-Q680i full waveform airborne laser scanner RIEGL VQ-580 online waveform processing airborne laser scanner www.riegl.com RiMTA automated range ambiguity resolution

23 One scan stripe transits 3 MTA Zones RIEGL LMS-Q680i PRR = 400kHz R u = 375m www.riegl.com Alt AGL [m] t [s] 0 14012010080604020 200 300 1000 900 800 400 500 600 700 MTA 3 MTA 2 MTA 1

24 RIEGL LMS-Q680i PRR = 400kHz R u = 375m www.riegl.com One scan stripe transits 3 MTA Zones Alt AGL [m] t [s] 0 14012010080604020 200 300 1000 900 800 400 500 600 700 MTA 3 MTA 2 MTA 1

25 RIEGL LMS-Q680i PRR = 400kHz R u = 375m www.riegl.com One scan stripe transits 3 MTA Zones Alt AGL [m] t [s] 0 14012010080604020 200 300 1000 900 800 400 500 600 700 MTA 3 MTA 2 MTA 1

26 RIEGL LMS-Q680i PRR = 400kHz R u = 375m www.riegl.com One scan stripe transits 3 MTA Zones Alt AGL [m] t [s] 0 14012010080604020 200 300 1000 900 800 400 500 600 700 MTA 3 MTA 2 MTA 1

27 RIEGL LMS-Q680i PRR = 400kHz R u = 375m www.riegl.com One scan stripe transits 3 MTA Zones Alt AGL [m] t [s] 0 14012010080604020 200 300 1000 900 800 400 500 600 700 MTA 3 MTA 2 MTA 1


Download ppt "Www.riegl.com High-Speed High-Density Data Acquisition in Airborne Laser Scanning Applications INTERGEO September 2011, Nürnberg Peter Rieger Andreas Ullrich."

Similar presentations


Ads by Google