The lidar has been and is involved in several national and international scientific programmes. The major projects include:

• Bavarian Climate Research Programme (1990-1997)
  The Bavarian Climate Research Programme (BayFORKLIM) was established in 1990. In the early phase of this programme several proposals were submitted for the development of a mobile lidar, one of which was successful in 1993. The system was manufactured by SensorLab (Munich) until August 1994. In the following years several smaller field experiments such as OPAP (North of Munich) and HAFEX (near Hohenpeissenberg, Bavaria) were undertaken. The programme was funded by the state of Bavaria.

• Validation of lidar measurements from Space (1994)
  In September 1994, the first spaceborne lidar was launched by NASA on Shuttle Discovery (STS-64). For evaluation purposes a ground-truth experiment was conducted in Northern Germany including an airborne lidar and several groundbased stations, one of which was ours. The project was funded by ESA.

• ACE-2 (1996-1997)
  The second Aerosol Characterization Experiment was conducted under the auspices of NOAA. Partners from all over the world ran an experiment including satellite observations, airborne measurements, and stations on land and the open ocean. Our lidar was operating from board of the R/V Vodyanitski between Portugal and Teneriffe for six weeks. The experiments were funded by the European Community, but, a follow-on project specially dedicated to data evaluation was not funded.

• Aerosol Forschungsschwerpunkt (1997-2000)
  In December 1997, the first German lidar network was established to measure aerosol distributions on a routine basis. This will constitute a solid basis for local aerosol climatologies at the involved stations in Munich, Garmisch-Partenkirchen, Leipzig, Hamburg and Kühlungsborn. An important aspect of this project was the comparison of algorithms and lidar-systems to ensure the quality of measurements and products. Measurement examples include
  
  
  • a full diurnal cycle of the planetary boundary layer and the derivation of extinction coefficients,
  • a clearly-layered boundary layer and
  • a cirrus cloud.
    
    This effort was funded by the BMBF.

• European Aerosol Research Lidar Network (2000-2003)
  In February 2000, the efforts of the German lidar network were extended to Europe within the framework of the so-called EARLINET. Sixteen stations between Sweden and Portugal, and between Wales and Belarus measure aerosol distributions and extinction coefficients twice a week. MULIS was used as a reference system for the quality control of the Greek, Italian and Slovenian lidar systems (confer SLICE in September/October 2000). This fact is an excellent appreciation of the group's expertise. The project is co-ordinated by the MPI in Hamburg and funded by the European Community. Detailed information can be found here.

• Ground Truth Center Oberbayern (2000-2004)
  The Ground Truth Center Oberbayern (GTCO) is setting a new standard in the cooperation between research and industry by developing innovative applications of remote sensing for the commercial market. Activities are focussed on improvements of traditional work routines in farming and water supply, calibration of satellite sensors and retrieval of atmospheric parameters Partners in this interdisciplinary project are the Geographical Institute and the Meteorological Institute of the University of Munich, and a company VISTA. All lidar applications in the GTCO were completely performed by our group.
  One of the highlights of the GTCO-project was the development of the portable lidar system POLIS. It was designed for operation in field experiments, from a trailer or onboard of an aircraft.

• EarthCARE Preparation (2001-2002)
  ESA plans to launch a spaceborne lidar within the framework of a joint European/Japanese project called EarthCARE (Earth Cloud and Aerosol Radiation Explorer). A comprehensive study investigating different options of the system design (selection of wavelengths, polarization, high spectral resolution channel, multiple scattering issues) and proposing a concept that minimizes the number of channels and data rate, and maximizes the instrument sensitivity, was performed in cooperation with the IfT (Leipzig). The experience of running our own lidar and dealing with „real“ data evaluation has proved to be a good basis for performing this work, which was funded by ESA.

• ICAROS-NET (2003)
  In the framework of a multinational project to improve remote sensing techniques for monitoring environmental parameters over large cities, a case study was performed over Munich. The experiment was conducted in two phases, one of which in summer, and one in winter 2003. They comprised groundbased, spaceborne and airborne instrumentation for measuring, e.g., trace gas concentrations and aerosols.
  We performed lidar measurements in and around Munich using MULIS (located at the institute) and POLIS, which was integrated in our van. The main purpose of the measurements was the assessment of vertical aerosol distributions and the homogeneity over the Munich area.

• SAMUM (2004-2010)
  One of the unsolved problems in aerosol physics is the characterization of mineral aerosols - one of the most relevant of all. A joint approach including climate modelling and experiments near the source region in the Saharan desert was accepted for funding by the DFG in February 2004. Partners within this research group („Forschergruppe“) are IFT Leipzig (leader of the consortium), MPI Jena, the DLR in Oberpfaffenhofen, and the Universities of Mainz, Bremen, Darmstadt, and our group.
  The Meteorological Institute applies new lidar measurement techniques and retrievals for optical properties of the particles, i.e., our work include „hardware“ and „software“ components. The field campaign during the Saharan Mineral Dust Experiment (SAMUM) was in Morocco in May/June 2006. In this campaign it was demonstrated that our concept of calibrating depolarization measurements is superior to previous techniques. A couple of papers are issued in a special issue of Tellus B in 2009.
  The second phase of SAMUM ended in March 2010. The main experimental activity were measurements in Cape Verde in January/February 2008. The goal of this campaign was to investigate mineral dust as „aged“ aerosol in different mixing states. It could be demonstrated that the combination of MULIS- and POLIS-data provides a unique data sets as it covers the vertical range from 70 m to the free troposphere. Furthermore, linear depolarization ratios at two wavelengths were provided with an accuracy, never reached before.
  The SAMUM activities of our group were supplemented by the development of a data base including a complete set of optical properties of non-spherical particles. Input parameters are the shape, the size and the refractive index of the particles.

• AMMA (2005-2009)
  The „African Monsoon Multidisciplinary Analyses“ (AMMA) is a European Project that aims to improve our ability to forecast the weather and climate in the West African region. It was motivated by the dramatic decrease of rainfall in the 1970-1990 decades.
  In 2006 the long term observations were supplemented by a series of extended field campaigns, one of which was conducted in the pre-monsoon season in January/February. We took part in this campaign with lidar (POLIS) measurements at Banizoumbou (Niger) to characterize aerosol distributions. It was shown that a mixture of biomass burning and mineral dust was present. This aerosol distribution was characterized by means of the vertical extinction coefficient profile and the linear depolarization ratio.

• European Aerosol Research Lidar Network: Advanced Sustainable Oberservation System (2006-2011)
  The EARLINET consortium continues its activities in the EC-funded project EARLINET-ASOS (European Aerosol Research Lidar Network- Advanced Sustainable Observation System). The main objectives of this „research infrastructure“ are: continuation of the EARLINET-measurements, the development of an effective (with respect to time and money) quality assurance, the optimization of the instruments an data evaluation (user friendliness, harmonization) and the improved organization of data exchange.
  Our group has the lead in the activity „Quality Assurance on hardware basis“. Several test were developed to unambiguously determine the quality of the optics and the alignment of the lidars. A dedicated campaign where 12 lidar systems were compared took place in Leipzig in September 2009. These lidars can be used as standards.

• ICAROHS (2009-2010)
  The scientific objective of the „Inter-Comparison of Aerosol Retrievals and Observational Requirements for Multi-wavelength HSRL Systems“ project (ICAROHS) is the investigation of spaceborne lidar missions beyond EarthCARE. In particular, the benefit of multi-wavelength high spectral resolution lidars for the retrieval of microphysical properties of aerosols is assessed. In this context the EarthCARE-simulator (ECSIM), which is the tool for the performance studies, is improved. Our group is responsible for the upgrade of the scattering library: a new data set for non-spherical particles has been included.

• ACTRIS (2011-2015)
  ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) is a European Project aiming at integrating European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds, and short-lived gas-phase species. ACTRIS will have the essential role to support building of new knowledge as well as policy issues on climate change, air quality, and long-range transport of pollutants.
  Our group is responsible for the quality asurance of the EARLINET lidars and leads an ad hoc working group on the potential of ceilometers for aerosol remote sensing. Detailed information can be found here.