Rick Evans' Amateur Lunar Photoclinometry, Spectroscopy, and Astrophotography -- Studies of the Moon and some General Astroimaging

Rick Evans' Amateur Lunar Photoclinometry, Spectroscopy, and Astrophotography
Studies of the Moon and some General Astroimaging

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Rick Evans' Amateur Lunar Photoclinometry, Spectroscopy, and Astrophotography

NAVIGATION

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Photo Gallery
Photoclinometry
Spectral Mapping
Lunar Spectrograph
Multispectral Images
5 UVVIS Spectra
Principal Component Anal
Imaging Spectrography
Lunar Meteorite Patrol
Dataset Calibration
Matrix Decomposition
Elemental Abundance
Publications
Selenology Today
Other Useful Links
Unprocessed Data
Guestbook
About Me
Astronomical Weather
Seeing & Imaging

INTRODUCTION

Welcome!

I am an amateur astronomer mainly interested in the moon, but also trying to improve my planetary and deep sky imaging. A few years ago I joined the Geological Lunar Research Group (see http://www.glrgroup.eu/old/home.htm and http://digilander.libero.it/glrgroup/) and am an active member. Some think amateurs can contribute nothing new to lunar studies and that "everything has already been done". I think the moon is still a good research subject for the amateur astronomer. I am interested in lunar topography, geology and spectral mapping. I use photoclinometry, spectroscopy, and multispectral and hyperspectral imaging as tools to study the geology of lunar features. This website includes my solar system and deep sky imaging, but the emphasis is on my lunar work.

If you want to leave a comment, feel free to sign the Guestbook or contact me at revans_01420 (at) yahoo (dot) com. My work in areas that interest me is outlined below, if you want to know more then choose the topic from the short menu on the left of the page.

Spectral Parameter Mapping:

I recently wrote a VBA program for Excel 2007 that will analyze Clementine UVVIS/NIR data and map mineral absorption trough band center minima, and band depth for orthopyroxene (890-945 nm), clinopyroxene (950-1000 nm) and olivine (1005-1095 nm) as well as mapping the FWHM (full width at half maximum wavelength), and the optical maturity index (OMAT) for any area of the lunar surface imaged by the Clementine probe between 415 nm and 2000 nm. The program is fully automated and produces the eight maps described above after inputting the nine Clementine band images from 415 nm to 2000 nm in txt format. A full description of the methodology should appear in the free online journal Selenology Today issue #14 scheduled for the spring of 2009 if all goes well. The maps are generated in txt format that is readily converted to 32 bit tiff format so that the spectral parameter values can be read from any map pixel using the free program ImageJ. The maps for Bullialdus below are only in jpg format. Over the next couple of months I hope to find the time to add Spectral Mapping to the website menu and provide additional details of this very interesting technique. This method is sensitive and trace amounts of pyroxines and olivine are detected, so it is important to look at trough depth. Finally, the standard USGS calibration of Clementine UVVIS+NIR has some problems most likely related to thermal signatures of the NIR cameras. The 1000, 1100, and 1250 nm image calibrations are particularly liable to error which shows up as complex absorption trough forms where they should be smooth and regular. This is particularly true of highlands features. I'm working on other calibration corrections using regression against Keck 120 color data but am too early into this process to know if a real improvement will be seen.

Photoclinometry:

Alpha Arago Dome* Heightmap (DEM) Dome Model Topographic map

* image by Paolo Lazzarotti (GLR Group)

Deep Sky Astrophotography:

When the moon isn't out or seeing is a problem I sometimes do deep sky imaging with my own equipment or using a rented remote-control telescope over the internet. Some of the deep sky images I've taken are shown in the PhotoGallery, Deep Sky submenu.

Whirlpool Galaxy (M51) Ring Nebula (M57) North American Nebula Dumbell Nebula (M27)

Planetary/Solar System Astrophotography:

Jupiter Animation Sept. 21, 2009 0032 UT to 0055 UT

High Resolution Lunar Imaging: (see lunar album)

My image processing protocol requires Registax 4.0 and Photoshop CS2 with Magic Focus plug-in. It has been updated as of May 16, 2009.

Download Image Processing Protocol: http://www.freewebs.com/revans_01420/ImagingProtocol-2.pdf

Lunar Terrain Maps:

Terrain Map of Theophilus & Cyrillus

Spectroscopy:

Lunar Broadband Multispectral Imaging:

Processing of Calibrated Clementine UVVIS Images:

Ratio Image (Tycho Rim) False Color Image (Tycho Rim)

Principal Component Analysis of Lunar Features:

Red=1st Principal Component, Green=2nd Principal Component, Blue=3rd Principal Component

Imaging Spectrography (Multi & Hyperspectral)

500-1000 nm AOTF Camera Adapter Spectral match for Olivine

Study of Dionysius West Rim Spectra Using a 9.25" SCT and Multiple UVVIS/NIR Interference Filters:

Dataset Calibration and Mixture Deconvolution:

Matrix Decomposition:

A multi-channel image based data matrix can be calibrated against a "ground truth" matrix using a matrix decomposition based on matrix regression. A simple example of this using color images is shown below. The left hand image is a normal RGB color photograph while the right hand image uses the red and blue channels and all pairwise products of these channels to synthesize an artificial green channel which closely approximates the original green channel. More details are given in the Matrix Decomposition sub-menu on the left of this webpage.

Performing a matrix regression yields a coefficient matrix which provides the following relationships between the green channel and the red and blue channels:

green = 1.397995*red -0.51202*blue +1.370348*(red*blue) - 0.212391*(red*red) + 0.308798*(blue*blue) + 676.1446

The general principal described in this example can be applied to multi-spectral data sets and can be used to calibrate one multispectral data set to another different data set regarded as "ground truth."

Extended SWIR (Short Wave Infrared) Imaging:

Note that olivine is darkest (shows maximum absorption) at 1000 nm.

Imager: SU320MX Indium Gallium Arsenide Camera (900-1700 nm range).

My Simple but Practical Shed Design Roll-Out Observatory:

The advantages of a roll-out design are 1) it is inexpensive 2) remote telescope control is possible via an umbilical thereby protecting the observer from mosquitos in summer and cold in winter 3) better sky view without viewing restrictions imposed by being inside a building 4) the tripod is placed on the brick patio which is a vibration free surface superior to a wooden building floor. The disadvantages are 1) need to roll or carry the telescope/mount in and out for each use 2) need to polar align before each use (but made easier by marking the pavement). The brick patio (tan cement-type brick, not red fire brick) provides a stable surface for the telescope mount and is less likely to harbor ticks and insects than grass, but it does retain and radiate heat after dark on really hot summer days. On a cool day with air temperature of 72 degrees in late afternoon, the brick surface is only 75 degrees F. But, under a baking hot summer sun, with an air temperature of 90 degrees F, the temperature of the patio bricks can be 103 degrees F. This can cause ground level turbulence similar to the "mirage" of heat waves seen on asphalt highways on hot sunny days. At twilight, the brick will begin to cool at about 3 to 4 degrees/hour toward the air temperature. If the temperature difference between the air and the brick surface is more than a couple of degrees F, then I generally wet the brick patio surface thoroughly with a garden hose and let the water evaporate away completely before setting up the mount (or else set up the telescope on grass instead). Watering the brick near twilight will reduce the gradient to a negligable level. I don't set the mount up on a wet surface, but only after the water evaporates away completely and cools the brick in the process. Before attempting hi-res imaging, the temperature of the brick patio surface should be measured and should be within a couple of degrees F of the air temperature. This is quick and easy to check with a quality thermometer.

In addition to this roll-out observatory I also use a large second floor observing deck attached to the house (shown below) which has the best sky view of all. The main problem here is that the deck floor is rubber coated wood, and so there is some vibration (roughly equivalent to a lite breeze) noticible in high power views of the moon and planets caused by the observer's movements on the deck. Also, the very dark floor radiates heat for several hours after sunset on warm days causing some image destabilization.