General aspects:

• Are the backscatter profiles of different systems (same and different manufactures) comparable?
• Which differences occur between the backscatter profiles depending on
  • altitude region
  • weather condition
  • time of the day
  • saturation effects
  • polarization effects

With respect to aerosol profiling: (responsibility DWD Hohenpeißenberg):

• Which instruments can be used for aerosol profiling in which part of the troposphere (PBL, lower and upper free troposphere)?
• What are the limits of the different instruments?
  • What is the measurement range depending on averaging time and aerosol load (optical depth)?
  • Daytime capability?
  • Performance in the overlap region?
  • Water vapor absorption – test of correction schemes and uncertainty estimation? (responsibility M. Wiegner, LMU Munich)
• What are optimal instrument settings for aerosol profiling?

With respect to cloud observations: (responsibility DWD Lindenberg)

• What are the differences in backscatter profiles for different cloud types?
• What are the limits in the detection of high clouds?
• What are the limits in the detection of low and mid-level clouds ?
• What are the differences between cloud detection algorithm between different systems/manufactures?