WEBINAR DISTANCE GATED IMAGING Seeing Objects only at Desired Distance 1 Impasse de la Noisette Verrières le Buisson 91370 FRANCE 1
WEBINAR
DISTANCE GATED IMAGING
Seeing Objects only at Desired Distance
1 Impasse de la Noisette
Verrières le Buisson
91370
FRANCE1
A quick company overview
2
SENSORS AND CAMERAS SUPPLIER
Module & cameras
SWIR & VISIBLE SOLUTIONS
INGAAS & CMOS SENSORS
HIGH DYNAMIC RANGE : > 120 dB
APPLICATIONS
SCHEDULE
3
Dr. Yang NI
Chief Technology Officer
Nicolas BAROAN
Business development manager
Frank CHRISTNACHER
Head of Advanced Visionics & Processing group at ISL
▪ Gated imaging operation principle
▪ New opportunities with gated imaging feature
▪ A real use case
SCHEDULE
4
▪ Questions & answers session
Ask questions directly online ! Download handouts specially selected for you !
Write them here during the
presentation and we will answer them
at the end of the presentation.
Operation principle
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The delay between the moment of shutter opening
and the illumination pulse determines the distance
range at which the objects are visible by the camera.
SEEING OBJECTS AT A PREDEFINED DISTANCE RANGE IN FRONT OF THE SENSOR
CAMERA
PULSED LIGHT SOURCE
Fast shuttering
Shutter control
SWIR band : 1,55 µm
Shutter only opened in
a short duration after
the illumination
Ultra-high
peak power
Illumination pulse Shutter opening
Delay
Camera
Distance
Objects
Operation principle
6
SWIR image gives a natural and easy to interpret view.
SWIR Thermal
Quality of transmission in air versus wavelength Eye-safety limit versus wavelength
NATURAL VIEW FOR HUMAN OBSERVER
GOOD TRANSMISSION IN ATMOSPHERE POSSIBLE EYE-SAFE OPERATION
Advantages of SWIR band
Operation principle
7
Basic Requirements for camera used in gated imaging
SHUTTER OPEN/CLOSE EFFICIENCY
SHUTTER OPEN/CLOSE SPEED
Defined by the rising and falling time of the shutter
opening
Sharp transition → Better distance range definition
Shutter open : collect as much light as possible
Shutter close : insensitive to light as possible
High efficiency → Better depth slice definition
Shutter
Time
Image
Depth
NIT InGaAs sensors suitable for active gated imaging
Operation principle
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Dedicated InGaAs
photodiode array
structures support
high dynamic range
optical signals
ALL DESIGN AND MANUFACTURE STEPS MASTERED IN INGAAS SENSORS AND CAMERAS
ROIC
PATENTED PROPRIETARY PHYSICAL PRINCIPLES AND STRUCTURES
InGaAs Photodiode Array Final hybridization
Special pixel design
assuring very fast
pixel reaction time
even with low
biasing current
Carefully design signal
paths assuring large
static and transient
current inside the pixel
array
Fast and short
shuttering
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Operation principle
NIT sensors’ performances
Effective exposure
time down to 100 ns
→ depth slices down
to 15 m
Rise time down to
20 ns → 3 m distance
range definition
WiDy SWIR 640V-SP
LASER : 4,8 ns pulse length - 4.5W power peak – 1550nm
Operation principle
10
Live demonstration
WiDy SenS :
640*480 pixels
exposure time 100 ns
Laser 1.55 µm
pulse length 30 ns
optical power : 10/40 W
Applications
Value chain
Wavelength 1.55 µm
Pulsed source
InGaAs sensor with
high shutter efficiency
and sharp exposure
time control
Gated imaging function
for selection of specific
depth slices in scenes
CAMERA PRODUCERSINTEGRATORS
LASER MANUFACTURERS
END USER
Delay generator for
synchronization laser
/ camera
sell to
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Applications
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What new opportunities with gated imaging feature ?
PERCEIVE IN SEVERE CONDITIONS
Through snowstorm, dense smoke, fog, heavy rain…
DETECT TARGETS
ENHANCE YOUR OBSERVATION
By suppressing background and foreground.
By estimating real distances.
Automotive
Defense
Surveillance & Security
Applications
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Automotive: Challenges for ADAS L4/L5 – Severe weather conditions
How to acquire robust
information in all weather
conditions ?1
2Lidar or infrared solutions
bridge partially the gap:
limited distance range or not
compatible with raining
situation / snow
A typical use case :
highway with vision capability at
200/300m in a dense fog or
heavy rain
3
[
[
[
[ -- car ---- obstacle --
Applications
14
Automotive: Challenges for ADAS L4/L5 – Severe weather conditions
SNOWSTORM EXAMPLE
The target useful signal is blurred among a
parasitic light, due to backscattering effect of
up-front particles.
The camera only records the rays coming
back at the distance of the object,
backscattering is removed, avoiding the
gray-out effect.
WITHOUT GATED IMAGING
WITH GATED IMAGING
Applications
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Security & Surveillance: Focusing on a selected Area and Identification of a Target
Acquiring images of a perimeter / target
through ambiant perturbations or
interference1
2Having identification capabilities while
being robust to ambiant light and external
parameters
Observation capabilities of active imaging
with discretion of passive imaging3
Applications
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Security & Surveillance : Focusing on preferred area
The signal reflected by very far
targets can be blurred among all
the signals coming from closer
targets.
By selecting only one slice in
the scene, the useful signal is
isolated to increase the image
quality.WITHOUT GATED IMAGING WITH GATED IMAGING
LONG-RANGE VISION
Applications
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Defense and military: an Instantaneous 3D modeling of the environment
Obtaining information of the surrounded
environnement1
2Alternative method suffers from low
Resolution such as Radar
3
Mapping the hostile environment in the
most secret method / Distance evaluation
Applications
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Tomography
15m
0 2
0 3
0 1Exposure time
Exposure time
Exposure time
Distance 1
Distance 2
Distance 3
With step by step delay increments, a
3D map of the scene is set up.
ESTIMATIONS OF REAL DISTANCES FOR
TOMOGRAPHIC RECONSTRUCTIONS
Active imaging at ISL
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French-German research institute of Saint-Louis
Active imaging at ISL
ISL prototypes
2002
NIR, 808 nm
2007
NIR, 808 nm
2009
VIS, 532 nm
2012
SWIR, 1.5 µm2013
SWIR, 1.5 µm
NIT sensor
2014
SWIR, 1.5µm
UAV detection
2015
NIR, 808nm
Very long range
<20km
2016
VIS, 532nm
Underwater
2017
SWIR/NIR,
1.06µm/1.57µm
Portable
NIT sensor 20
Active imaging at ISL
Security-oriented applications
21
Stadium surveillance Urban surveillance
Active imaging at ISL
Military applications
22
Sniper detection
Active imaging at ISL
Military applications
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Vision through military smokes
Active imaging at ISL
Dual-use applications
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3D vision
Active imaging at ISL
Dual-use applications
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UAV detection
Active imaging assistance
500 m 1500 m
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THANK YOU AND LET’S ANSWER YOUR QUESTIONS !
Dr. Yang Ni
Nicolas Baroan
Frank Christnacher
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Q1: Are all NIT solutions InGaAs only or do you have Silicon based sensors? if InGaAs only, why?
Questions & Answers
A1: NIT offers a full range of CMOS High Dynamic Range products and InGaAs products. However, the
CMOS products are not dedicated for Gated Imaging. Only some of our InGaAs products (WiDy SWIR
640 & WiDy Sens) are made for Gated Imaging with very short exposure time and fast rising time. The
SWIR band brings benefit for gated Imaging due to a better Atmosphere transmission and possible
eye safe operations.
Q2: Can you use the NIT WiDy cameras to detect (the illumination of) gated imaging systems? Will the new
camera be able to integrate all the light during an integration period?
A2: It’s possible with some special adaptation. Actual camera can not integrate during all the frame
time, but we have other solutions to fulfill this requirement.
Q3: What are NIT's solutions for gated imaging?
A3: NIT offers 2 main products for gated imaging: The WiDy SWIR 640 and the WiDy Sens – a full
description is available on our website www.new-imaging-technologies.com. They offer booth VGA
resolution (640 x 512). The WiDy Sens is more dedicated to long range imaging (few kms).
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Q4: How high shutter efficiency can be reached ?
Questions & Answers
A4: The shutter assures an extinction rate better than 0.01% at 20us before gate opening
Q5: How many images need to be processed to detect a sniper through military smoke? To what confidence
interval?
A5: The principle of detection of a sniper is called “Pointed Optic Detection” : when you are illuminating the
scene, the retroreflection in the optical sight of the sniper gives a very strong response (saturation) in the active
imaging system. So far, the sniper is detectable immediately when he points his weapon inside the FOV of the
active imaging system…
To make an automated detection, we process the images with a circular BLOB detection…
Q6: What's the shutter speed of the SWIR camera? The gating is done in circuit level?
A6:The shutter can be opened and closed in 20ns with a minimum duration of 100ns. It’s done
at pixel readout circuit level.
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Q7: What is the shortest repetition rate of the camera? What is the distance resolution estimate??
Questions & Answers
A7: The repetition is limited by either the camera frame rate or laser recharging time.
Q8: What limits the performance of your Gated Imaging devices? Shutter speed? QE? Noise? Power consumption?
A8: Shutter speed limits only the range depth. The image quality and absolute range are closely
dependant of QE and Noise level.
Q9: And the shutter speed?
What is your minimum integration time? And what's the duty cycle you can use at this integration time?
A9: The minimum exposure time is 100ns with 20ns rising time. The duty cycle is low when
sensor is used in gated mode.
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Q10: How about seeing a car at 200 meters in dense fog?
Questions & Answers
A10: Active imaging in the SWIR domain presents very high capability to see through dense scattering
media. The only case where these performances are lower is with water droplet fog.
In this case, the performances depend on the particle diameter. With water droplets above 1µm of
diameter, there is no problem to see through.
With particle diameter in the Mie regime, the performance drastically decreases.