OliNo

Renewable Energy

Spectrum of moon light

Posted by Marcel van der Steen in Explanation
Tags:
Add comments

005_moonWhen I was looking for a spectrum of moonlight, I could not find it on the internet. As I do a lot of lamp measurements myself (see the category lamp measurements), I decided to measure the moon spectrum myself and put that info available on the internet.

Measurement circumstances

The measurement has been done on 14th of April 2014. It was an evening with few clouds and we had a full moon, well visible. Taking measurements with the spectrometer SpecBos 1211 can then be done in two ways.

1) measurement of the illuminance (in lux). However the expected illuminance is only 1 lux and that results in a very faint spectrum with signals for each wavelength too close to the noise limit to have a nice signal.

2) measurement of luminance (in Cd/mˆ2), and that requires a very well alignment of the measurement device in the direction of the moon, as the sensitivity area of the device in this mode is only two degrees wide.

I mounted the spectrometer on a tripod and kept on aligning and measuring until I had an output with a high signal.

Measurement results

Here the spectrum and derived parameters.

001_MoonSpectrum_177cdm-2

002_MoonSpectrum177cdm-2_24measurements

003_CRI_moonspectrumMacLv

Latsly an csv-file with the measurement data, which is an average of 24 measurements.

file-icon-csv-300px

5 Responses to “Spectrum of moon light”

  1. Ur-1el Says:

    Great job. I was very helpful. I want to thank you very much. Can I repay you somehow?

  2. George Felix Says:

    Great work, I’m thinking of doing my PhD on the cooling effects of the moonlight.

    Do you have the Latitude and Longitude of the experiment location?

    If I understand correctly, the experiment was done on a full moon. Have you run the experiment on a new moon (Black No Moon) in order to compare the results between the two?

    Can I use your information in my dissertation and if so, please send me your titles.

  3. mvdsteen Says:

    Dear George. I measured the moon from my address. In the measurement file you can find the time and date. The address coordinates are: latitude: 51.42359906, longitude: 5.40894538. I did not redo the measurement at other moon cycles. It was already hard enough to get a nice measurement with the full moon (I had to point it very precisely as the spectrometer had to be in radiance mode and has then only an acceptance window of 1.8 degrees).
    You can use the data, my info is found here: http://www.olino.org/us/contributors/marcel-van-der-steen

  4. Richard Davis Says:

    Marcel…
    This is very well done, original observation. It’s very much appreciated.

    Do you have any ideas about what might be causing the notch in the lunar light spectrum at about 760 nm? That is an interesting spot on the wavelength line because many IR filters have that as a pass band. I’m hoping there is something to pass.

  5. mvdsteen Says:

    Richard, it seems to me the absorption effect of O2, see also this image from Wiki.

Leave a Reply

 

WP Theme & Icons by N.Design Studio
Privacy Policy Entries RSS Comments RSS Log in