1 / 23

The 1st Continuous Measurements of Nightsky Brightness with a New Low Cost Luxmeter

Darksky 2008. The 1st Continuous Measurements of Nightsky Brightness with a New Low Cost Luxmeter. André Müller Max Planck Institute for Astronomy Heidelberg Dr. Günther Wuchterl Thüringer Landessternwarte Tautenburg. Motivation. Quantitative statements 1st Continuous measurements

mhughey
Download Presentation

The 1st Continuous Measurements of Nightsky Brightness with a New Low Cost Luxmeter

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. Darksky 2008 The 1st Continuous Measurementsof Nightsky Brightnesswith a New Low Cost Luxmeter André Müller Max Planck Institute for Astronomy Heidelberg Dr. Günther Wuchterl Thüringer Landessternwarte Tautenburg

  2. Motivation • Quantitative statements • 1st Continuous measurements • Comparison between Jena – Obs. Tautenburg • `Light weather´ • Long-time trends – disappearance of the Milky Way • Integration in a meteorological station

  3. Motivation • Low costs (~100 Euro) • Low maintenance • Easy to operate • Global network with 1000 stations • Additional grid for `How many stars...´

  4. Methods • Conventional luxmeter • Photometer (e.g. Zacharov, 1962) • Simple digital camera (e.g. Schmidt, 2004) • CCD-Camera (e.g. Cinzano et al., 2000) • Imaging with fisheye lenses (e.g. Cristaldi et al., 2000) • Anchor visual estimations (e.g. `How many stars...´) • Solar cell (Kerschbaum/Posch)

  5. Methods - Disadvantages • High costs • Usage depends on weather • Monitoring programs not always possible • Complex data reduction and analysis • All sky capability

  6. Our Low Cost Luxmeter • Using a conventional solar cell as detector • 1st prototype developed and built in summer 2005 • 1st light 26.04.2005 • Starting with monitoring program on 3rd Nov 2005

  7. Jena Measuring Site

  8. Measuring Site – Jena City Operating for ~4 months 4m telescopic mast transparent bowl for weather protection Pico-Amperemeter located in temperature stable staircase

  9. Measuring Site – TLS Tautenburg

  10. Solar Cell Advantages • Low costs (~100 Euro) • Simple setup • Continuous Measurements • Weather independent • Direction dependent measurements possible • Could operate without PC and additional current (future) • Mobility • Measurements over 8 orders of magnitude (!) • High resolution in time

  11. Calibration - Linearity • For Calibration VOLTCRAFT (0.01 lx - 20.000 lx) was used • In the future automatic calibration using the moon

  12. 10 pA Dark Current Lower detection limit ~50-100 µlx (natural night sky brightness ~250 µlx)

  13. First Results - Examples Darkest night in Tautenburg

  14. First Results - Examples Change of night length (Data from 2006, Tautenburg)

  15. First Results - Examples Night with full moon and clouds

  16. snow rain clear First Results - Examples Influence of weather

  17. First Results - Examples Modulation of illumination due to the moon

  18. First Results - Examples New Year‘s Eve 2005/2006

  19. Jena - Tautenburg >1/2 E(full moon) Jena is at least 40 times brighter than Tautenburg

  20. Jena - Tautenburg Jena Nov 2005 – Jan 2006 Tautenburg 2006

  21. Jena - Tautenburg Jena Nov 2005 – Jan 2006 Tautenburg 2007

  22. Darksky 2008 Thank you for your attention!

  23. First Results - Examples Night with full moon

More Related