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

5

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

8

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

9

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

11

Applications

12

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

13

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

15

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

16

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

17

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

18

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

19

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

23

Vision through military smokes

Active imaging at ISL

Dual-use applications

24

3D vision

Active imaging at ISL

Dual-use applications

25

UAV detection

Active imaging assistance

500 m 1500 m

26

THANK YOU AND LET’S ANSWER YOUR QUESTIONS !

Dr. Yang Ni

Nicolas Baroan

Frank Christnacher

27

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.