Lunar Orbiter Composites - fermigas/ltvt GitHub Wiki

Description

This page contains Lunar Orbiter images assembled from the digital scans at the USGS Lunar Orbiter Digitization Project. The long, skinny Lunar Orbiter High Resolution images transmitted from orbit have traditionally been divided into three roughly rectangular segments, designated H1, H2, and H3 -- all exposed at the same instant. The present page reassembles the images into their original format by overlapping the segments with Photoshop. Each image was then loaded into LTVT and calibrated by locating on it two control points from the 1994 ULCN.

Interested users wishing to display these same frames in LTVT may download the present images and the accompanying calibration data. Even without downloading the images it's possible to ask LTVT to use the calibration data file. In that case a "Find Images" command will tell the user which Lunar Orbiter frames contain the point of interest even though the frame may not be available on the user's hard drive.

Calibration Data

LTVT calibrations for the three-frame composite images shown below: LunarOrbiter_FullFrame_CalibrationData.txt (24 kb; 27 Sep 2008)

Note: this file specifies a default image download folder of "C:\LTVT\Lunar_Orbiter". Unless you use the LTVT Image Grabber in its "Cal data + URL list mode", you will need to be manually edit the destination folder name to match the location of the folder to which the images are actually downloaded. Please use a text processor for this purpose.

The quality of the calibrations can be judged by loading the images into LTVT with this calibration data and then superimposing the complete set of 1994 ULCN control points.

URL List

The following list gives the web address of each image displayed below. It can be used in conjunction with the Image Grabber to automatically download local copies of them to the user's hard drive.

LunarOrbiterComposites_URL_List.txt (9 kb; rev. 19 Jul 2008)

Downloadable Image Files

Each of the following images was concatenated from the smaller frames from the USGS Lunar Orbiter Digitization Project, or (in two instances) from the LPI's on-line copy of Bowker and Hughes. Note that the square thumbnail shows only the central section of the image. Most of the images are 16300 pixels wide by 4375 pixels tall. The dates are when the images were assembled into the present format.

If the present images are used in conjunction with the calibration data file, then the latter needs to be manually edited with a text processor to make the image directory (the default is "C:\Lunar_Orbiter") correspond to the actual folder name in which the downloaded images are stored. The images will load significantly faster if they are converted to the bulkier Windows .BMP disk format. In that case, the file extensions in the calibration data file will also need to be edited from .JPG to .BMP (the image format does not alter the control point pixel locations, and hence does not alter the calibration).

Note: the pixel scale of these images is identical to that of the scanned images on the source websites. They are archived here in a "Quality 6" JPEG format, which may cause some slight loss of contrast for the finest details.

Composites of low resolution scans from the LPI website