1 / 33

Effects of spatially inhomogeneous photomultiplier sensitivity on lidar signals and remedies

Effects of spatially inhomogeneous photomultiplier sensitivity on lidar signals and remedies. Volker Freudenthaler Meteorologisches Institut der Universität München, Munich, Germany. R5600.

galvin-williams
Download Presentation

Effects of spatially inhomogeneous photomultiplier sensitivity on lidar signals and remedies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Effects of spatially inhomogeneous photomultiplier sensitivity on lidar signals and remedies Volker Freudenthaler Meteorologisches Institut der Universität München, Munich, Germany R5600 V. Simeonov et al., Influence of the Photomultiplier Tube Spatial Uniformity on Lidar Signals, Appl. Opt. 38, 5186-5190 August 1999. Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  2. Hamamatsu PMT R5600 / R7400 • included in modules: • H57xx • H67xx • H7468 • H7155 • H7825 • H7829 old R5600 R5600 new R7400 Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  3. MULIS - Multi Purpose Lidar System Optical design for 3 backscatter + 2 extinction + 1 depolarisation channel 500 mm from telescope Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  4. POLIS - Portable Lidar System Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  5. Biaxial lidar model for ray tracing • Considered parameters • axial distance of laser and telescope • laser axis tilt • laser divergence • discrete ray source cross sections • Software: ZEMAX-EE Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  6. Biaxial lidar model for ray tracing • Considered parameters • axial distance of laser and telescope • laser axis tilt • laser divergence • discrete ray sourcecross sections • Software: ZEMAX-EE Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  7. Focal spot positions Range  angle of incidence  radial position of focal spots 5 km 150 m Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  8. Focal spot positions  PMT Range  angle of incidence  radial position of focal spots 5 km 150 m Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  9. Image of tele-focus on PMT Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  10. Image of tele-focus on PMT Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  11. Spot positions on PMT over range Ratio to real signal Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  12. Radial shift of axis position on PMT Ratio to real signal vertical and horizontal shift ±1 mm Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  13. Horizontal and vertical orientation of PMT Ratio to real signal horizontal vertical horizontal vertical Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  14. Diffusor • Diffusor doesn't help • if not very far from PMT • high loss of signal intensity • bad especially for Raman channels ratio to real signal Spot PMT Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  15. How to find the best PMT position large image of primary mirror (PM)  large PMT necessary Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  16. How to find the best PMT position Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  17. How to find the best PMT position Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  18. Spot on PMT with eyepiece PMT -1 0 +1 mm 150 m Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  19. Spot on PMT with eyepiece over range PMT -1 0 +1 mm 150 m Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  20. Biaxial spots on PMT over range axial position 0 mm Ratio to real signal – Spot does move Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  21. Biaxial spots on PMT with eyepiece axial position 0 mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  22. Biaxial spots on PMT with eyepiece axial position +1mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  23. Biaxial spots on PMT with eyepiece axial position -1 mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  24. Eyepiece + diffusor Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  25. Eyepiece + diffusor + mirror tube "Smart diffusor" Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  26. Biaxial spots on PMT with smart diffusor axial position noncritical Ratio to real signal + Spot does not move + no change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  27. Monoaxial spots on PMT axial position 0 mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  28. Monoaxial spots on PMT axial position -1 mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  29. Monoaxial spots on PMT axial position +1 mm Ratio to real signal + Spot does not move – change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  30. Monoaxial spots on PMT with eyepiece axial position 0 mm Ratio to real signal + Spot does not move + little change of intensity distribution Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  31. Solutions Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  32. Solutions mechanical accuracy: better than ± 1 mm lens focal lengths: better than ± 1% (± 2% usual)  optical control of result necessary Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

  33. End Thank you for your attention! Effects of spatially inhomogeneous photomultiplier sensitivity….. http://www.freudenthaler.de/ILRC22

More Related