Lidar Sensors, Today & Tomorrow. Christian Sevcik RIEGL Laser Measurement Systems

Transcription

1 Lidar Sensors, Today & Tomorrow Christian Sevcik RIEGL Laser Measurement Systems

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3 o o o o Online Waveform technology Stand alone operation no field computer required Remote control through wireless network Inclination sensors, GPS, digital compass RIEGL VZ-400 RIEGL VZ-1000 RIEGL VZ-4000 range up to 600 m accuracy 5 mm range up to 1,400 m accuracy 8 mm range up to 4,000 m accuracy 15 mm Laser PRR up to 300 khz, Laser PRR up to 300 khz, Laser PRR up to 200 eyesafe Laser Class 1 camera option eyesafe Laser Class 1 camera option khz, eyesafe Laser Class 1 built-in calibrated digital camera RIEGL VZ-6000 more than 6,000 m range accuracy 15 mm Laser PRR up to 200 khz, Laser Class 3B for measuring snowy and icy terrain

4 o o o Full / Online Waveform technology Calibrated Amplitude / Reflectance Flying altitude from 2,500 ft 10,000 ft Airborne Scanners for planes: RIEGL LMS-Q780 flight altitude up to 10,000 ft laser pulse repetition rate up to 400 khz full waveform analysis RIEGL LMS-Q680i automatic Multiple-Time-Around (MTA) processing full waveform analysis for an unlimited number of target echoes operating flight altitude up to 5,000 ft AGL Laser PRR up to 400 khz, practically eyesafe Laser Class 3R Airborne Scanners for helicopters RIEGL VQ-820-G for coastline and shallow water mapping visible green laser beam for water penetration Laser PRR up to 520 khz, Laser Class 3B RIEGL VQ-580 for measurements on snow and ice operating flight altitude up to 4,000 ft AGL Laser PRR up to 380 khz, Laser Class 3B RIEGL VQ-480 operating flight altitude up to 2,500 ft AGL Laser PPR up to 300kHz, eyesafe Laser Class 1

5 Technology Overview WAVEFORM PROCESSING, POINTCLOUD ATTRIBUTES

6 Waveform Lidar MULTITARGET CAPABILITIES THROUGH WAVEFORM PROCESSING

7 Target Laser pulse Echo signal Plane target, nearly orthogonal measurement angle Plane target, oblique measurement angle Multiple reflection of the laser pulse (spatially distributed targets) Multiple reflection of the laser pulse (equal distance targets) Multiple reflection of the laser pulse (vertically stacked targets)

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9 Gaussian decomposition Gaussian system response assumed Provides a pulse width robust and fast Full Waveform Processing System response fitting System response assumed to be known Non-linearities of the receiver can be modelled Provides a pulse shape deviation Realtime processing (3Mio echos/sec) Online Waveform Processing

10 Value added pointcloud Geometry & Attributes ATTRIBUTES PROVIDED BY LASER SCANNERS BASED ON WAVEFORM PROCESSING TECHNOLOGY

11 Geometry

12 Geometry Geometry & Reflectance

13 Geometry Geometry & Reflectance Geometry & True Colour

14 Pointcloud attributes provided by RIEGL sensors Echo Return Number: Knowing the waveform, means knowing the number of returns. Echo return number can be used as an additional filtering criterion for objects. Timestamp [s] X [m] Y [m] Z [m] Class Pulse Shape Deviation Return Number Reflectance [db] Amplitude [ ] Red Color Green Color Blue Color

15 Pointcloud attributes provided by RIEGL sensors Calibrated Amplitude: Left: Grey scale encoding of point cloud according to calibrated amplitude. Note that brightness decreases from near objects to far objects. Reflectance: Right: Grey scale encoding of point cloud according to reflectance of target. Range of encoding is -20 db to 3 db with respect to white diffuse target. Note that brightness is nearly independent from distance. Timestamp [s] X [m] Y [m] Z [m] Class Pulse Shape Deviation Return Number Reflectance [db] Amplitude [ ] Red Color Green Color Blue Color

16 Pointcloud attributes provided by RIEGL sensors Pulse Shape Deviation: Beside target range and amplitude, the pulse shape of the echo signal is compared to the pulse shape representing the so-called system response. The pulse shape deviation can be interpreted as the comparison of the area below the shape curve of the target echo and the area of the shape curve of the emitted pulse. From left to right: Raw pointcloud, Points selected with respect to pulse shape deviation, filtered pointcloud Timestamp [s] X [m] Y [m] Z [m] Class Pulse Shape Deviation Return Number Reflectance [db] Amplitude [ ] Red Color Green Color Blue Color

17 Pointcloud attributes provided by RIEGL sensors Return Number Calibrated Amplitude / Reflectance Pulse Shape Deviation / Pulse Width LAS format supports additional attributes: Extrabytes Documented since LAS 1.4 Timestamp [s] X [m] Y [m] Z [m] Class Pulse Shape Deviation Return Number Reflectance [db] Amplitude [ ] Red Color Green Color Blue Color

18 Sample Applications TYPICAL FIELDS OF APPLICATION

19 BARE EARTH EXTRACTION Calculation of a terrain model of wide areas. airborne Laserscanning with long range sensors for high altitudes. Example: Forested area in Styria scanned with a RIEGL LMS- Q680i airborne scanning system in This is an example of airborne scandata used for landscape planning. Vegetation has been filtered to extract the ground information. Contour lines are automatically derived for mapping applications. POINTCLOUD RETURN DTM

20 TERRAIN FEATURES Determination of erosion in forested areas. Removing the vegetation layer by filtering the Lidar data unveils bare earth data, which can be used to detect and map regions of erosion.

21 TRAILS Determination of erosion in forested areas. Removing the vegetation layer by filtering the Lidar data unveils bare earth data, which can be used to detect and map regions of erosion.

22 EROSION Determination of erosion in forested areas. Removing the vegetation layer by filtering the Lidar data unveils bare earth data, which can be used to detect and map regions of erosion.

23 ELEVATION Relative Tree heights Given a reference surface (DTM) each point below or above the surface can be coloured due to its distance to the surface. RELATIVE TREE HEIGHT DTM DTM acts as reference surface

24 DEADFALL Shrub layer extraction Lidar waveform systems provide a very good penetration of vegetation down to bare earth.

25 DEADFALL Shrub layer extraction Lidar waveform systems provide a very good penetration of vegetation down to bare earth.

26 GROWTH PERIOD Time series of Lidar data 2 Lidar datasets: march 2011 september 2011 Colors in grey indicate no significant change in height. Yellow to red indicates growth up to 3 meters. Blue color is negative development (harvested areas).

27 BUFFERED SELECTION Surveying of powerlines to determine vegetation encroachment Airborne laser scanning on a rotary wing platform. The example shows a powerline extracted from the lidar data. A clearance profile is used to determine the vegetation to be cut.

28 DIAMETER BREAST HEIGHT Sample scans taken with RIEGL VZ-400 Color coded reflectance reading

29 DIAMETER BREAST HEIGHT Points filtered by Reflectance, Pulse Shape Deviation & Return Number

30 Ground points filtering to create DTM DIAMETER BREAST HEIGHT

31 DIAMETER BREAST HEIGHT Ground points filtering to create DTM Select points at 1.5m above DTM

32 PlotView of selected stems DIAMETER BREAST HEIGHT

33 DIAMETER BREAST HEIGHT Plot # 3387-G # DBH X Y Z Conf Meas PlotView of selected stems Diameter extraction

34 Latest Developments / Outlook FROM THE ALCHEMISTS LAB 532 nm 905 nm 1064 nm 1550 nm relative reflectance [%]

35 AUTOMATION Schiebel CAMCOPTER S-100 UAS carrying the RIEGL VQ GU Project milestones: Integration of laser scanner, IMU-GNSS, aerial camera and Control Unit Migration of control and acquisition software to an embedded system, operating autonomously during flight. Live data downlink

36 l=1550 nm l=1064 nm l=532 nm MULTIPLE WAVELENGTH

37 l=1550 nm l=1064 nm l=532 nm MULTIPLE WAVELENGTH

38 MULTIPLE WAVELENGTH l=1550 nm l=1064 nm l=532 nm NOT JUST A POINT CLOUD BUT A POINT CLOUD WITH VALUABLE ATTRIBUTES

39 Thank you

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