The database in Lunar Calculator originated from a file of crater names and positions from NASA. Using this as a starting point, Roger Fell used the highly accurate images from the Clementine mission to create a database (called "lushgaz") with my Clementine Skimmer software. There are over 7000 entries and Roger checked every one, adjusting coordinates and diameters when necessary (which was often!).
Every now and then, Roger will have updated the file, which can be downloaded from his webpage, or the Lunar Calculator website. Lushgaz is an acronym for "LUnar-SHort-GAZette". The "long" lunar gazette comes on the Clementine CD Vol 15, which is included on the Lunar Calculator CD. That gazette contains additional information particular to the Clementine mission and images, such as projection offsets and image scaling factors. These are not required for this program.
The vast majority of features in the database are craters. You can add new feature types as well as features themselves (see below). As time goes on, I will be adding more as observers send me their lists. If you have a list of features and their lat/lons, I can add them to the database for others to use. For a linear feature, only the position of the middle point is given. I hope to change this in a future version. You can go to linear features (such as Rupes Recta, aka the Straight Wall), but it won't plot them.
Feature types are: ALBEDO FEATURE, CATENA, CRATER, DOME, DORSA, DORSUM, FOSSA, LACUS, LANDING SITE, MARE, MISCELLANEOUS, MONS, MONT, MONTES, OCEANUS, PALUS, PLANITIA, PLANUM, PROMONTORIUM, RAY, RIMA, RIMAE, RUPES, SINUS, VALLIS. You can add to this list by editing the file "featype.txt" in Notepad or WordPad (default directory is C:\Program Files\Lunar Calculator 2.00). A new feature type will automatically show up in the list the next time you restart the program.
The database file is a simple text file "lushgaz.txt", made up of lines like this one:Tycho -43.27 -11.19 102.00 Name lat long diam (km)
and this continues in one long line (turn the word wrap off when viewing or editing the file)
Crater Tycho Brahe; Danish
feature type historical reference
Do NOT use TAB, only spaces, and follow the columns used by other database entries. Longitude is positive EAST, by IAU regulation! What may be somewhat confusing is that colongitude is positive westward (left as seen from the northern hemisphere).
Lunar Calculator will not plot quasi-linear features like dorsa, montes, rima, ray, vallis, nor the large basins or mare (Orientale). Anything else (including new features), it will try to plot as a circle. Point features, like landing sites, will be plotted as a circle of 1 pixel radius, even if its size is zero.
The demo version will plot craters only as small as 3.0 km or 1.8 mi in diameter.
There are likely some errors remaining in the database - over time these will be stamped out. The most common "fault" you will notice is that the crater outlines are sometimes too big. While some craters have very sharp rims and little raised shoulders, others are quite complex. There is no exact definition for crater diameter, and selenographers over the years have contributed to the NASA database with their own flavor.