User Guide What LTVT Can Do For You

What LTVT Can and Cannot Do

LTVT Can:

• Draw a map of the Moon (or other planet) as a flat disk seen in projection from any distant point, such as on Earth (or elsewhere).
• Tell you the positions in the sky of the Sun and Moon (or selected planet) at the specified time.
• Accurately indicate the position of the terminator based either on manually entered sub-solar and sub-observer points, or on the same data independently computed by the program using the downloadable JPL ephemeris files
• Accurately portray the angular orientation of the Moon in the sky as seen through a particular telescope configuration at a particular hour of the night.
• Allow you to easily zoom in and re-center the image.
• Identify all named features falling within the image area, representing their centers by dots.
• Automatically plot and label such dots with user-selectable colors and fonts.
• Display the origin of the feature names or such additional information as may be present in the dot file.
• Perform the same operations with other dot-like data, such as Clementine altimeter points.
• Take you instantly to any named feature, showing you both how it looks from overhead and in projection from Earth or elsewhere.
• Measure distances on the planetary surface and interpret the length of shadows in terms of elevation differences.
• Search for future or past times with similar lighting conditions or librations.
• Search through a user-provided list of photographs or observations, and tabulate them by the position of the terminator and the magnitude of the librations.
• Search through the same list and automatically flag those that were made when lighting conditions were similar to the present simulated image.
• After a simple calibration procedure, load any photo of the Moon (or other planet) taken from Earth or elsewhere as a texture so that all the above functions can be performed directly on it, rather than on a specially prepared reference map.
• If a Digital Elevation Model is available, create accurate simulations of the three dimensional appearance of the surface, including cast shadows, as seen in projection from a distant point.

LTVT Does Not:

• Predict eclipses.
• Tell you the dates and times of the lunar phases.
• Tell you about the geology of the features portrayed in the images.
• Blur or sharper the reference map: LTVT copies and displays pixels exactly as they appear in the reference map, using a single pixel from the source image of each pixel in the displayed image. Competitive products, such as VMA, may do a better job of rendering by averaging data over a larger area in the source image.