Validation for the EarthCARE observations withuse of spaceborne lidar ACDL and ground-based
lidar-net over China
Guangyao Dai1, Songhua Wu1, Kangwen Sun1, Wenrui Long1, lidar group1 ,Jiqiao Liu2, Weibiao Chen2, Shengguang Qin3, Xitao Wang3, Rongzhong Li3
1 Faculty of Information Science and Engineering, Ocean University of China, Qingdao, China
2 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China

3 Qingdao Leice Transient Technology Co., Ltd., Qingdao, 266100, China

2023/11/16 @ ESA-ESRIN

1Content

1. ACDL/DQ-1 introduction and comparison with EarthCARE

2. Recent lidar instruments at OUC
3. Summary22. ACDL/DQ-1 introduction
Specifications
Wavelengths
Laser energy

Parameters532nm, 1064nm and 1572nm；≥130mJ@532nm≥190mJ@1064nm≥40mJ@1572nm

Divergence

50μradStability of the laser 1572nm: 0.6MHZ@10000s
linewidths
1064nm: 5MHz@10000s

Telescope aperture
FOV

20Hz@1572nm (On/Off dual-pulse)
20Hz@532nm and 1064nm (dual-pulse)
1000mm190μrad

HSRL

Iodine cell: OD > 25dB

Receiver channels

532nm HSRL
532nm parallel-polarized
532nm cross-polarized
1064nm aerosol
1572nm CO2PRF➢ The first spaceborne lidar (IPDA) for CO2 detection in the world➢ The first spaceborne Iodine-based HSRL working at 532nm inthe world3

1. ACDL/DQ-1 introduction: Data products
level

Data processing

Data products

FormatLevel 0The observation data obtained by downlinking multi-packet data integrity
inspection and data splicing through the two channels of the satellite.

Raw data

RAWLevel 1AProcess the level 0 aerosol data, obtain the profiles of 532 nm and 1064
nm channels, with the geographic location and height corrected.

Profiles data of 532 nm and 1064
nm channels

HDF5

Level 1B

Process the level 0 CO2 data, obtain the profiles of 1572 nm channel, withthe geographic location and height corrected.

Profiles data of 1572 nm channel

HDF5

Level 2A

Attenuated backscatter coefficient with systematic constant correction

Attenuated backscatter coefficient

HDF5

Level 2B

Differential Absorption Optical Depth (DAOD) products

DAOD

HDF5

Level 2C

Cloud and aerosol products including extinction coefficient, backscatter
coefficient, depolarization ratio, AOD, lidar ratio and color ratio(vertical resolution: 50 m);(Horizontal resolution: 10km/3.3km adjustable at this moment);

Cloud and aerosol opticalproperties

HDF5

Level 2D

XCO2

XCO2

HDF5 4

1. ACDL/DQ-1 introduction: Aerosol and cloud optical properties(a) Depolarization ratio(b) Backscatter coefficient(c) Extinction coefficient(d) Lidar ratio(e) Color ratio(f) Scenario classification

Nighttime measurement
over Europe and Africa
Aerosol classification

5

1. ACDL/DQ-1 introduction: orbits
Satellite trajectory during 24th June, 2022 as an example
Red denotes the daytime/ascending orbit, Black represents the nighttime/descending orbits.

The ACDL/DQ-1 orbits in a sunsynchronousorbit

at705-km

altitude with an ascending nodeequator crossing time of 13:20 LST.
The orbit inclination of 98 ◦ provides
coverage between 82◦ N and 82 ◦ S,
with orbit tracks that repeat around51 days.

61. ACDL/DQ-1 introduction: orbit quick look and prediction
Official nameSpace Surveillance Catalog Number

Owner

Operational Status

Data Source

DAQI 152257

People’s Republic of China

Operational

AGI’s Standard Object Data Service

Satellite Tool Kit (STK): an analysis engine for calculating the position andattitude of the satellite at any given moment, and DQ1 has been
uploaded to the SSC coded satellite database, which can be easily used
for satellite orbit display and orbit prediction.

Export predicted satellite orbit information in
the target coordinate system

ACDL and CALIOP simultaneous measurement: 2-3 times higher

7

1. ACDL/DQ-1 introduction: validation with CALIOP

Latitude2022-0704-09:43

Longitude

Latitude2022-0704-08:43

Longitude

ACDL and CALIOP simultaneous measurement: 2-3 times higher

8

2. Recent lidar instruments at OUC➢Raman lidar - WATCL➢Atmospheric and ocean HSRL
➢Coherent Doppler wind lidars

9Coherent Doppler wind lidars and Raman lidar
Our Product s

WATCL Raman Lidar

Specifications
Wavelengths

Parameters
355nm；

Laser energy≥100mJ@532nm

PRF

20Hz@355nm

Telescope aperture 300mm/Cassegrain
Temporal resolution 1 s (adjustable)
Vertical resolution 7.5 m (adjustable)
Data products

α, β, δ, LR, WV, T, RH (6+ channels)

Atmospheric and Oceanic HSRL

Specifications
Wavelengths

Parameters532nm/355nm；

Laser energy≥10mJ@532nm; ≥10mJ@355nm;

PRF

1kHz@532nm&355nm

Linewidth
100MHz@532nm
Temporal resolution 1 s (adjustable)
Vertical resolution 7.5 m (adjustable)
Data products

α, β, δ, LR

 The Atmospheric and Oceanic High-spectral-resolution
lidar based on Iodine absorption cell technique is underdeveloping.
 The scheduled accomplishment time: April 2024
 One scheduled cruiser expedition: September 2024

Coherent Doppler Lidar
mainly measure wind/aerosol
profiles in atmospheric/planet

Signal-to-Noise ratioboundary layer (PBL) and lower
troposphereBe noted: Only parallelSpecifications
Wind3D 6000WindMast PBL
1550 nm
1550 nmQualification

Wavelength
Repetition rate
Pulse energy
Pulse width
Detection range
Data update rate
Range resolution

10 kHz160 μJ
100 ns to 400 ns
80 m to 6000 m
4 Hz
15 m to 60 m

polarization components!

10 kHz100 μJ
100 ns to 400 ns
30 m to 4000 m
4 Hz
15 m to 30 m

Extinction coefficient/CBH/BLH

VLOS

Aerosol
Paticles

VBackscatter coefficientWind profiles

Vertical velocities

f D = 2VLOS / 

Pre-amplifier
Seed laser

Splitter  AOM  + f

Power amplifier
FiberWedge

 + fi
Telescope

ISO&FilterISO = 1550nm

Opticalswitch

Fiberi

10μJ

ISO&Filter

100μJ

 + fi + f D

Wind fields (10 mins averaged)

Turbulence + fi + f DSplitterfi + f D
BalancedDetector

A\DFFT

13Signal processing

Wind directions (10 mins averaged)

SD of the vertical velocities

"The Belt and Road" Lidar Network for Dust Monitorin g

巴丹吉林沙漠
玉门
敦煌

金塔

腾格里沙漠

酒泉
嘉峪关民勤

张掖
金昌
武威白银
兰州

图例

庆阳
平凉

临夏

卫星遥感

定西

一期项目

天水

二期项目（中科光电）碌曲二期项目（兰州大学）
二期项目（安光所）
陇南激光风雷达气溶胶雷达

18（颗粒物）+5（风）+4（LPDM）+1（平台）+卫星
18（Mie lidar）+5（wind lidar）+4（LPDM）+1（Mobile）+SatelliteOnshore & Offshore Doppler LiDAR Network

Floating lidars

Glidar lidars

LiDAR networking information data platform• A multi source, multi type, and multi-dimensional information data platform helps improve the level ofcomprehensive air quality control services and refined meteorological monitoring and forecasting, pollution
emergency prevention and control.
• In this project, all of the data are the potential reference data sources for EarthCARE CAL/VAL.

Shipborne Lidar s in Navigation Obser vation ofOceanic and Atmospheric Profile3. Summary
1. The first spaceborne lidar for simultaneously observation of CO2 and aerosol based on IPDA and HSRL
techniques are introduced, including the data processing, orbit display and prediction.

2. The data products (including backscatter, extinction, depolarization ratio and lidar ratio) from ACDL/DQ-1
can be utilized for the cross-checking of data products from EarthCARE after the wavelength convert.
3. The lidar-net over China including HSRL, Raman Lidar, Doppler lidar is capable of providing simultaneousobservation of aerosol profiles with EarthCARE. Actually the lidars are also be able to be applied forshipborne measurements.
4. We have already learnt some lessons during the CAL/VAL for Aeolus, which may benefit for the CAL/VAL for
the EarthCARE.

Email:
wush@ouc.edu.cn
daiguangyao@ouc.edu.cn

17Construction of "Ground -Sea-Air-Space" Stereoscopic
Remote Sensing Monitoring System by Integrated Lidars

Thanks19

1. ACDL/DQ-1 introduction: Data processing and Retrieval algorithms
A data processing and optical properties retrieval
method adapted to the specific characteristics of ACDL-A
global observation dataset

Optical properties

Scene classification

Validation

Data applications
20