Outline●The current configuration of the ESA MObile RAman Lidar (EMORAL)●

New functionalities: wavelength-dependent polarization, Raman water vapor, broadband
fluorescence.

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Examples of measurements in different environments.

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Recommendations for the smooth operation

Motivation and objectives
The EMORAL lidar development started in 2007 with objectives to:●●●●take part in campaigns all over Europe in order to enhance European competencein the domain of Cal-Val campaigns for EOP missionbuild and maintain in ESA a key competence, such as the lidar knowhow
test atmospheric lidar concepts and technologies
provide datasheets for scientific research and other ESA activities

Since then, several instrument upgrades!

Here we talk only upgrades in last ~5 years …

EMORAL UPGRADES I
September 2017 till March 2018
● mobile platform upgrade:
new lVECO van nad its modifications,e.g.: additional air-con, manual hatch in the roof
(ESA – NOA collaborative effort)● lidar system upgrade:
re-design of transceiver with new laser, new telescope
new design of polychromator,
new/upgraded transient recorders(ESA – UW, LMU, Raymetric collaborative effort)DATA QUALITY ASSESSMENT: UW & INOEEMORAL UPGRADES IMain goals:●●Redesign of transceiver to assure
decreased overlap down to ~250-350m andincreased height resolution to 3.75m
Extend the number of measured signals
to assure more data products of higher quality(data products cross-validation)

COMPROMISE: use of the existing partsin the re-designed version as long as they
do not decrease significantly the overall
lidar performance!

EMORAL UPGRADES I
New, custom designed transciver (Raymetrics, Greece) comprising:● More powerful Nd-YAG laser, (SpitLight 400, InnoLas, Germany)
operating at 1064 nm (112 mJ), 532 nm (103 mJ) and 355 nm (128 mJ),
with a repetition rate of 10Hz and pulse length 5-7 ns.
● Smaller size Cassegrain telescope primary mirror of 300 mm andadjustable FOV 2-3.6 mrad
New design of detection channels(Raymetrics, Greece) comprising:● Signals simultaneously recorded(analogue + photon-counting mode)by PMTs (except 1064 nm (analogueonly, APD) with new 16 bits
transient recorders (TR40-160,Licel, Germany)

Excellent durable
mechanics designand manufacturingby Raymetrics

EMORAL UPGRADES I
Compact wavelength separation unit:

3 elastic Mie channels
1064 nm, 532 nm, and 355 nm
3 vibrational Raman channels
nitrogen at 387 nm and 607 nm
water vapor at 407 nm
2 depolarization Mie channels
532 nm and 355 nm

Easy rotation of wholedetection unit for calibration
purpose, components tests andreplacement

EMORAL UPGRADES I
Developments increasing measurement quality:● automated telecover mechanism● calibration system for polarization measurements● sliding filters for Raman and polarization channels● possible rotation of whole detection unit
● CCD camera for monitoring the outgoing laser beam● several laser interlocks for safe lidar operation
Additional needs of operation in extreme conditions(winter/summer, peatland):● two oil heaters for winter operation● insolation chimney● external UPS for system stabilization● camera for sky-monitoring

EMORAL UPGRADES II
September 2019 till October 2020
Purpose:● additional purely technical upgrades
conducted at Raymetrics● campaigns related to ESA missions at NOA

Recommendation for changes was prepared by
POLIMOS Team and provided to ESA (G.Tzeremes)
and Raymetrics (G.Georgoussis).

EMORAL UPGRADES III
September 2022
Essential upgrades conducted at Raymetrics:● fluorescence channel● Replacement of oldest PMTs
● aircraft radar for safety● more powerful air-conditioning● van: roof painting and door insulation

Recommendation for changes was prepared by
POLIMOS Team and provided to ESA (P.Ribes)
and Raymetrics (G.Georgoussis).

EMORAL UPGRADES III
Major upgrade: fluorescence channela) new broad band interference filer 420-500 nmb) new Dichroic Mirror at the entrance of the WSUc) new Long Pass Beam Splitter separate 407 and 420-500 nmd) new Eyepiece and PMT for fluorescence detectione) new Transient Recorder for fluorescence channel (an, pc)
NOTE: additionally PMTs replaced at 407 and 607 nm

Van to be visited outside
the Conference hall 

Recent EMORAL intercomparisons●●●2018 against POLIS (LMU-MIM) & PollyXT (TROPOS) lidars
2019 against RALi (INOE) & PollyXT (TROPOS) lidars
Several tests but no direct intercomparison after the EMORAL upgrade in 2020

● Recent: September 2022 against POLIS (LMU-MIM), RALi (INOE), ALPHA (INOE)
ACTRIS-CARS site at INOE

LIDARS

Intercomparison
ALPHA INOE
(reference)
POLIS LMU
(reference)
EMORAL ESA/UW

Lidar comparison at single
location at ACTRIS CARS(INOE, Magurele, Romania)

EMORAL QA tests and optimization
Rayleigh fit
Lidar misaligned
too much signal
in the near-range

Lidar aligned
properly thanks
to beam-camera

Issues at far-field(loosing signal)

Correct signal atnear and far-fieldEMORAL QA tests and optimization
Telecover test
Lidar aligned properly thanks to the automated telecover mechanism.
Low overlap achieved.

EMORAL QA tests and optimization
Depolarization Calibration at 355 and 532 nm thanks to easy +/- 45 deg rotation
Very good result for both wavelengths even with no correction for GHK parametes!

Research Campaigns
Goals:
Derivation of new data products in different environments:● Direct data products (fluorescence backscatter coefficient)● Fluorescence-Mie-Raman synergy products (fluorescence capacity)
New algorithms:● Algorithm for synergic evaluation of lidar signals
Results:● Successful retrieval of fluorescence data products.
● Aerosol typing using fluorescence capacity and depolarization ratio.

Campaigns

Fluorescence Backscatter Coefficients
Remarks:{●●●●High consistencyresults(similar time)
Observable variability(at same day)Lowest aerosol load Oracac
Exotic conditions –Worcław: highly polluted
urban atmosphere inwintertime

Cloud layers from ~ 3 km
Wroclaw 22 and 23 Nov

mind the scaleFluorescence Capacity
Promising outcome:●●●●More stable GF obtained at355 nm
Obtainable until below 500 m
Unique: combining input form
WV to correct dataNo other lidar with suchsynergic observations in somany locations!

Aerosol properties
To be optimized:•Reduction/filteringof the data noise•Data products with usof the ACTRIS Single
Calculus Chain Tool
Current:
Beta 355, 532, and 1064
obtained using SCC not optimal
for high aerosol load.
Noise handling (current MAsmooted 5-10 points).

Potential for typing
Clear separation of theproperties depending on
location of measurement andaerosol type / mixture(only appetizer shown)SummaryLessons learned:- Attention must be paid to transportation of lidar (proper packing, sensible driving and root planning)- There is a need for 2 operators and 1 data evaluator during campaigns as NRT is required- Isolating chimney is crucial for operation in wintertime and during hot summers- Implemented ACTRIS QA tools help critically in lidar operation
Recommendations:- Some analog signal disturbances mainly on 1064nm channel: further cooperation with InnoLAS
for better electrical isolation of the laser power supply and with LICEL to optimize detection with APD.
- Exchange the oldest five Transient Recorders (1064, 532p,s, 355p,s)
Follow-up activities:- Using the current lidar for ESA field campaigns is feasible even in tough conditions !