1Geiger-Mode Sensing Technology
1Geiger-mode Sensing Technology
• Frisbee players at 50 meters
• Green car (15% reflectance) at 150 meters
• Black motorcycle (3% refl.) at 250 meters
• 60 mph highway traffic, at 350 meters
Geiger-mode LiDAR Sensing Technology
2Geiger-Mode Sensing Technology
Geiger-mode LiDAR –The Dawn of Digital Mapping
Peter Kostoulas, Sr. Applications Engineer
3Geiger-Mode Sensing Technology
3Geiger-mode Sensing Technology
• Expertise in indium phosphide lasers and avalanche photodiodes (APDs)
• Pioneers in single-photon, Geiger-mode sensing technology
• Specialization in long-range 3D LiDAR imaging to < 3 cm resolution
• Staff of 50, with over half holding advanced technical degrees
• Customers are leaders in their respective industries around the globe
• Autonomous navigation
• Defense/targeting
• 3D mapping
• Quantum communications
• Satellite tracking and long free-space optical communications
Introduction to Princeton Lightwave
4Geiger-Mode Sensing Technology
4Geiger-mode Sensing Technology
• What is Geiger-mode?
• Some aspects of Geiger-mode detection technology
• Imaging with Geiger-mode cameras
• Applications
• Mapping
• Disaster Management
• Resource Management
• Autonomous navigation, including driverless cars
• Conclusion
Contents
5Geiger-Mode Sensing Technology
5Geiger-mode Sensing Technology
• Single event detection is often referred to
as Geiger-mode detection, a term derived
from X-rays
• A Geiger-mode detector (GmD) emits a
macroscopic current from the detection of
a single photon
• Used with a clock, a GmD is ideal for
detection and Time-of-Flight (TOF)
ranging applications
What is Geiger-mode (Gm) detection?
Laser
Detector Reflector
Time of flight 2T1
6Geiger-Mode Sensing Technology
6Geiger-mode Sensing Technology
Geiger-mode is sensitive to a single photon
Number of
photonsPeak power
1,000,000
100,000
10,000
1,000
100
10
1
Geiger-
mode
Linear-
mode
< 500 photons are detectable only in Geiger-
mode
Photon
Detectivity
l = 1550 nm,
1 nsec pulse
128 mW
12.8 mW
1.28 mW
128 nW
12.8 nW
1.28 nW
128 pW
Single-photon, or
Geiger-mode, APDs
• Are 500 times more
sensitive than
Linear-mode APDs
• Respond digitally
when sensing
photon(s) • (Output current of L-M
APD is proportional to
# of photons)
7Geiger-Mode Sensing Technology
7Geiger-mode Sensing Technology
Flash LiDAR: Linear-mode processes light classically
• LiDAR is based on relative reflectance: at a given distance, the higher the reflectance, the
more photons are returning from the target
• Reflectance, then, is the probability that a single photon reflects rather than is absorbed
by the target
• Linear-mode LiDAR uses individual flashes of quadrillions
of photons (1mJ equals 7.8x1015 photons per pulse at 1550
nm) to obtain reflections at repetition rates of 20-30 Hz
Photons traveling to
reflector from source
Percentage of photons
reflected back
33%
reflector
• Resultant image is from trillions of photons per flash returning from the target to the detector
67%
reflector
8Geiger-Mode Sensing Technology
8Geiger-mode Sensing Technology
Flash LiDAR: Geiger-mode processes photons serially
• Geiger-mode uses high repetition rate (200 kHz) at low energy
(1 nJ = 7.8x109 photons at 1550 nm)
• An image is formed based on the percentage of flashes that register a detection
33%
Target
Reflectance
67%
Case
A
Case
B
• Geiger-mode obtains same relative intensity information
faster and more efficiently than linear-mode
9Geiger-Mode Sensing Technology
9Geiger-mode Sensing Technology
Geiger-mode detects through obscurants
75 m 300 mGate opened Obscurant is 25% transmissive,
25% reflective, 50% absorptive
100% specularlyreflective
target
T = 0 ms, 0 photons
T = 0+ms, 16 photons
T = 0.25ms, 16 photons
T = 0.5-ms, 16 photons
10Geiger-Mode Sensing Technology
10Geiger-mode Sensing Technology
75 m 300 mGate opened Obscurant is 25% transmissive,
25% reflective, 50% absorptive
100% specularlyreflective
target
T = 0.5+ms, 8 photons (4 reflected / 4 transmitted)
T = 1-ms, 8 photons (4 reflected / 4 transmitted)
T = 1+ms, 4 photonsObscurant detected
Geiger-mode detects through obscurants
11Geiger-Mode Sensing Technology
11Geiger-mode Sensing Technology
75 m 300 mGate opened Obscurant is 25% transmissive,
25% reflective, 50% absorptive
100% specularlyreflective
target
T = 2ms, 4 photons
T = 3ms, 4 photons
T = 3.5-ms, 4 photons
Geiger-mode detects through obscurants
12Geiger-Mode Sensing Technology
12Geiger-mode Sensing Technology
75 m 300 mGate opened Obscurant is 25% transmissive,
25% reflective, 50% absorptive
100% specularlyreflective
target
T = 3.5+ms, 2 photons (1 reflected / 1 transmitted)
T = 4-ms, 2 photons (1 reflected / 1 transmitted)
T = 4+ms, 1 photon (reflected) Target detected!
Geiger-mode detects through obscurants
13Geiger-Mode Sensing Technology
• Gm technology originally developed for imaging through canopy
Geiger-mode LiDAR sees through foliage
Tree canopy obscures ground Geiger-mode images vehicle under canopyImages courtesy of Harris Corp.
14Geiger-Mode Sensing Technology
14Geiger-mode Sensing Technology
• For the same
brightness source,
Geiger-mode has a
500 x advantage for
(Field of View x
Distance)
• (Diode laser has
1/10th lower beam
quality than a fiber
laser)
27dB margin lets Geiger-mode image farther/wider
1
10
100
1,000
10,000
0.010 0.032 0.100 0.316 1.000 3.16 10.00 31.62 100.00
# o
f FP
A P
ixel
s
Distance (km)
# of FPA Pixels as a Function of Range and Light Source
Fiber Laser - Lm Diode Laser - Gm Fiber Laser - Gm
Fiber laser, in Linear-
mode, detects 1 point at 1
km range
50x enhancement500x enhancement
128 x 32 FPA
15Geiger-Mode Sensing Technology
15Geiger-mode Sensing Technology
• Geiger-mode camera
equivalent to Linear-mode
camera
• 32 x 32 on 100 µm pitch
• 128 x 32 on 50 µm pitch
Geiger-mode Focal Plane Array
32 x 32 Photodetector Array
Focal Plane Array with PDA mounted on Readout
Integrated Circuit
GmD pixel (contact side)
128 x 32 FPA on ROIC6.4 x 1.6 mm2 PDA
3.2 x 3.2 mm2
16Geiger-Mode Sensing Technology
16Geiger-mode Sensing Technology
High Accuracy, High Resolution Geiger-mode Cameras
Model ArrayTiming
(ps)
Accuracy
(cm)
Returns
per
second
Blind
Readout
time (µsec)
Framed Data Output
Kestrel 32 x 32 250 3.75 200 M 3
Falcon 128 x 32 500 7.5 400 M 7
Free Running Data Output
Merlin 32 x 32 300 4.5 800 M N/A
10 x 10 x 10 cm3
New!
17Geiger-Mode Sensing Technology
17Geiger-mode Sensing Technology
Laser Rx with
CameraScanner
Position
(INS)
Sys. Control & Data
Acquisition ComputerOperator
Data Storage
LiDAR Functional Block Diagram
3D LiDAR Imaging with Laser and Gm Camera
Courtesy of
Harris Corp
Laser & camera
embedded in
scanner
~ 40 x 40 x 40 cm3
18Geiger-Mode Sensing Technology
18Geiger-mode Sensing Technology
Geiger-mode maximizes resolution at long-range
Images courtesy of Harris Corp.
Linear-mode Geiger-mode
• From 8 km altitude, Geiger-mode provides ten times higher resolution
Details such
as power
lines and
shrubs now
visible
Significant
infrastructure detail
enhances disaster
response initiatives
19Geiger-Mode Sensing Technology
LiDAR in Resource Management
Courtesy of Harris Corp
What Can Geiger-mode Deliver?
• High level of detail
– Resolution capability that
surpasses USGS QL1 (8 pts/m2)
– Rich point cloud
• Ability to image below canopies
• Lower cost of obtaining data
– Ability to scan more often,
which enables tracking
changes more frequently and
effectively
– Ability to manage larger areas
due to time and cost savings
20Geiger-Mode Sensing Technology
LiDAR in Disaster Management
• Enhanced speed of collection
– Higher altitude operation allows more coverage in shorter time period
– Time is critical for disaster response
• Resolution capability that surpasses USGS QL1 (8 pts/m2)
– Provides detail information regarding power lines and other critical
infrastructure
– Enhanced ability to identify transportation link breakdowns for first
responders
• Lower cost of obtaining data
– Enables multiple passes for ‘before’ and ‘after’ or for situation updates
What Can Geiger-mode Deliver?
7 km aerial imaging at 20 pts/m2, McGuire Nuclear Station, N.C. Uses Falcon 128x32 Geiger-mode LiDAR Camera Courtesy of Harris Corporation. Ref: W. E. Clifton, B. Steele, G. Nelson, A. Truscott, M. Itzler, M.
Entwistle, “Medium Altitude Airborne Geiger-mode Mapping Lidar System” Proc. SPIE 9465, 946506 (May 2015).
21Geiger-Mode Sensing Technology
• Power line detail visible from 7 km AGL
• Disaster relief needs to clearly identify:
– Missing or damaged utility wires
– Damaged roads
– Impacted infrastructure
• Geiger-mode achieves this
– Faster than linear
– More efficiently than other methods
Infrastructure Details Critical to Disaster Relief
7 km aerial imaging at 20 pts/m2, McGuire Nuclear Station, N.C. Uses Falcon 128x32 Geiger-mode LiDAR Camera Courtesy of Harris Corporation. Ref: W. E. Clifton, B. Steele, G. Nelson, A. Truscott, M. Itzler, M.
Entwistle, “Medium Altitude Airborne Geiger-mode Mapping Lidar System” Proc. SPIE 9465, 946506 (May 2015).
22Geiger-Mode Sensing Technology
Geiger-mode for Autonomous Navigation
23Geiger-Mode Sensing Technology
23Geiger-mode Sensing Technology
Geiger-mode camera used for autonomous flight
https://www.youtube.com/watch?v=udQ3WoK_Wdk&feature=youtu.be
• Sikorsky Blackhawk
navigates autonomously
using Falcon 128 x 32
Geiger-mode camera at
1550nm
Unmanned
24Geiger-Mode Sensing Technology
24Geiger-mode Sensing Technology
ParameterGeigerCruizer™
Demo System
GeigerCruizer™
Long-Range
Image Format (Pixels) 512x64 512x128
Field of View (pixel) 2 mrad 2 mrad
Field of View (H x V), total 60° x 7.5° 60° x 15°
Raw Data Points/Image ~5 Million ~10 Million
Geiger-mode essential for high speed self-driving
• GeigerCruizer™ LiDAR images 300 meters, at 10% reflectance
• Real-time video refresh rates
• Enables use of eye-safe, scalable diode lasers
• Capability proven via GeigerCruizer™ Demo System
Demo System
25Geiger-Mode Sensing Technology
25Geiger-mode Sensing Technology
• Fog highly
adverse to
imaging
• 80%
attenuation
• Backscatter
Geiger-mode images vehicle in dense fog
Noise Filtered in SoftwareUnfiltered
Dense fog
Shrubs Shrubs
• Software
filtering
– Resolves car and
shrubs
– Removes
backscatter and
other noise
26Geiger-Mode Sensing Technology
26Geiger-mode Sensing Technology
GeigerCruizer™ Demo System
27Geiger-Mode Sensing Technology
27Geiger-mode Sensing Technology
• Geiger-mode processes photons digitally and in real-time
• Resolution and imaging speed of Geiger-mode is unsurpassed
• 3D LiDAR applications being transformed
• Maps generated faster, at higher resolution
• More detailed images through obscurants: leaves, soot, rain,
fog, …
• High speed autonomous navigation & driving being enabled
• Geiger-mode extends imaging beyond traditional 3D LiDAR
Conclusion
28Geiger-Mode Sensing Technology
THANK YOU!
GEIGER-MODE LIDAR –
THE DAWN OF DIGITAL MAPPING
www.princetonlightwave.com
29Geiger-Mode Sensing Technology
Geiger-mode Sensing Technology