Automatic Operation of Lidar Systems at Remote Sites

– PollyNET –

Dietrich Althausen, Ronny Engelmann, Holger Baars, Birgit Heese, Thomas

Kanitz, Detlef Müller, Mika Komppula, Frank Wagner, Andreas Hänel …

What would be the ideal Lidar network for aerosol typing?

• worldwide measurements• 1 type of system 1 software also for data

retrieval• Optical information of particles: 3 backscatter

coefficients, 2 extinction coefficients, at least 1 depolarization ratio

inversion to microphysical particle parameters

We try to do this.http://polly.tropos.de

also at remote sites

one data format and one type of system parameters

one software for backup, quicklooks, …, data retrieval

Emitter

Simultaneously emitted 180 mJ (1064 nm)

110 mJ (532 nm)

60 mJ (355 nm)

Divergence of beam < 0.5 mrad

Receiver

Diameter of main mirror

Receiver field of view

Channels

355 nm, 532 nm, 1064 nm

387 nm, 607 nm

355 nm or/and 532 nm

30 cm

1 mrad

Elastic 3

Raman 2

Depolarization 1

Althausen et al., J. Atmos. Ocean. Tech., 2009

one type of system

compactautomaticcomplex but easy to handleRaman lidar3 + 2 + 1

yields to closer interaction of all lidar operators

support in maintenance is provided,

solving of instrument problems,

distribution of hardware and software improvements,

test routines are exchanged, and

faulty data are identified faster.

PollyNET Network of Systems

http://polly.tropos.de

EUCAARI – European integrated project on aerosol cloud climate air quality interactions OCEANET – Autonomous measuring platforms for the determination of material and energy exchange between ocean and atmosphere ALPACA – Aerosol Lidar measurements at Punta Arenas in the frame of Chilean - GermAn cooperation

http://polly.tropos.de

PollyNET

1 + 3 systems

Cooperation:IfT, FMI, Uni Evora

≈ 2350 days measurements

EARLINET

EUCAARI field sitein the Amazonian rain forest / Brazil

Satellite dish forinternet connection

Aeronet sun photometer

Controlling from Germany

The aim of these efforts is to backup the data at home immediately after measurement, guarantee access to quicklooks, collect the data on one server, and guarantee long-term storage of data (as sometimes required by projects).

Autonomous measurements according measurement schedule

System performs backup of data to polly.tropos.de

At polly.tropos.de:

Storage of data, entry in MySQL-database, quicklook generation

PollyNETWordwide measurements

Network of Data

Web-Server with start page: http://polly.tropos.de MySQL database provides the right plot

How did we ensure our worldwide measurements?

• Cooperation with local colleagues• Automatic measurements (also during interrupted

internet connection)• Remote control of all parts of the system• Daily check of the transferred data• Logfiles according all parameter changes, error

messages, temperatures inside the system• Fast reaction in case of errors

http://polly.tropos.de

Brazilian Observations Overview 2008(bold=days with observations)

Start

Laser damage

End of observations!211 days of lidar observations

(294 possible days)

Wet season observations

Dry season observations

occasional power failures

source: polly.tropos.de

15 08 2008

mean

Overview dry season, Brazil, 2008 55 night time observations

0

1

2

3

4

5

0 1 2 3 4 5 6

Backscatter coeff. at 532 nm

(Mm-1 sr-1)

Hei

ght (

km)

Backscatter coefficients of 55 night time observations in the dry season.

0 1 2 3Part. Bsc. Coef., Mm-1sr-1

0

1

2

3

4

5

Hei

gh

t ag

l, km

355 nm532 nm1064 nm

0 30 60 90 120 150Part. Ext. Coef., Mm-1

0

1

2

3

4

5

355 nm532 nm

0 20 40 60 80 100Lidar Ratio, sr

0

1

2

3

4

5

355 nm532 nm

0 1 2 3 4Ångström Exponent

0

1

2

3

4

5

355/532

532/1064

355/532

0.1 0.13 0.16 0.19 0.22Eff. Radius, µm

0

1

2

3

4

5

ssa reff

0.7 0.8 0.9 1Single Scattering Albedo

15 August 2008 22:35 and 23:35 UTC

rather high and indicate small particles

dominated by biomass burningBacktrajectory analysis supported this, too.

Althausen et al., J. Atmos. Ocean. Tech., 2009

Automatic Retrieval of Particle Backscatter und Extinction Coefficient

• Automatic products!

• EARLINET-ASOS (SCC)Aldo Amodeo “Optimisation of data processing”Giuseppe D’Amico “EARLINET Single Calculus

Chain”

• Turner, D. D., R. A. Ferrare, L. A. Heilman, W. F. Feltz, and T. Tooman (2002), Automated retrievals of water vapor and aerosol profiles over Oklahoma from an operational Raman lidar, J. Atmos. Oceanic Technol., 19, 37–50.

old webpage: http://iftwetter.tropos.de/VAP/

Example of Automatically Evaluated Measurements

Summary / Outlook

Planned cooperation

NIER, South Korea; UA, Australia

Improvements

automatic retrieval algorithms for and

PollyNET is a working lidar network

-it’s a network of 1 system type (not restricted to a continent or region).

-it’s a network for data handling.

-made possible measurements at remote sites.