Earthshine Site
Earthshine Observation and Measurement of Earth's Albedo
Fresh Result
- Earthshine today's observing log
- Monthly Lunar Almanac:
- Year 1998
- Year 1999
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February, |
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April |
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June, | July, |
August, | September, |
October, | November, |
December |
- Year 2000
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October, |
November, |
December |
- Year 2001
| January, |
February, |
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December |
- Year 2002
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December |
Earthshine spectra taken at Paloma Observatory in September, 1999
Camera test on July 3, 1999
Meaning of airmass fit plots in everyday log:
Several steps of correction are done before we get the the final numbers of MS, CS and ES
in the everyday plots:
1. normalized data counts recorded from CCD to exposure 1 second;
2. for BS and CS, divide the data counts by the transimission of the BS filter;
3. normalize data to a standard lunar radius;
4. normalize data to a standard Earth-Moon distance;
5. normalize data to a standard Sun-Moon distance;
And here we are with the numbers; but wait a minute, the numbers plotted are natural
algorithm of the data counts after the above 5 steps.
Meaning of [A*] plot
PlotI(top): reflectivity of Lambert surface vs. lunar phase, meaning that if observing the earth
at the position of full moon, the Lambertian earth reflectivity should be zero while when
observing the Lambertain Earth at NewMoon position, Lambertian earth reflectivity is maximum (1).
PlotII(MidI): the reflectivity of the true earth without normalization to Lambertian surface,
showing the same tendency as in PlotI but since the earth is not a Lambertain surface, the
reflectivity is generally lower and not changing in the exactly the same way as lambetain surface.
PlotIII(MidII): the reflectivity of the earth normalized to Lambertain surface, meaning that in small
lunar phase, the real earth's reflectivity is higher than Lambertain surface while in larger lunar phase,
real earth's reflectivity is smaller than Lambertian surface.
PlotIV(bot.): [A*], which is -2.5*log(PlotIII).
Third-step corrected lunar phase function plot from
December 1, 1998 to May 12, 1999
From top to bottom: original observation; corrected with crescent; corrected with sun-moon
position; corrected with libration.
Detailed look at the phase function plot: 1. Phase > 0 ;
Phase < 0
Lunar phase function and Sun-Moon relative position
(enlarged plot around full moon).
Lunar phase function and libration plot from November 26, 1998 to April 5, 1999.
From top to bottom:
-
moonshine intensity read out from fiducial points.
- crescent intensity corrected with the area of the bright portion.
- libration Alpha (longitude).
- libration Beta (latitude).
Lunar spectra taken at MLO: first light.
[A*](and average) plot from November 26, 1998 to April 08, 1999(NG transmission taken as 0.0117).
Comparison of [A*] at different colors
and seasonal change:
-2.5*alog10(A*_c/A*_w), or [A*]_c - [A*]_w ; c respresents different colors
(R/G/B from top to bottom) and w is white light. The average of the plots are:
(from top to bottom): 0.252+/-0.100, 0.025+/-0.127, -0.292+/-0.131, or, the
reflectivity of the earth at blue/green/red color is 1.31/0.98/0.79 that at
white light.
[A*] (and average) plots over all colors from 1994 January to 1995 August:
White,
Red,
Green,
Blue
Lunar phase function plot of all colors
from 1994 January to 1995 August.
From top to bottom, the colors are:
white, red, green/yellow, blue.
Practicalities
Science Links
Miscellaneous
- January 30, 1999: CD backup data of 94, 95, 98nov26 to 99jan31 (all ~620*9 MB).
- February 9, 1999: Exabyte backup data from 98aug27 up to 99feb09 (all 4.5GB).
- May 2, 1999: CD backup data up to 99apr28(~620*5).
- June 25, 1999: Exabyte backup (two copies) from 99feb01 to 99may(lunar99_8)(~5Gb);
CDROM (two copies) backup data up to 99may(lunar99_8). CDROM(2 copies) backup of all
analysis reults of 1994, 1995, 1998, 1999jun25.
- September, 1999: Exabyte backup up to 99sep.
- February, 2000: CDROM backup to 00feb (lunar00_01).
- May, 2000: Exabyte backup to 00apr.
- Aug, 2000: CDROM backup to 00jul (lunar00_08).
- Aug, 2000: Exabyte backup to 00jul.
May the same moon light shine over thee n' me
Over ages, over mountain n' sea.
Su Shi(1067AD)