Plate-Solving Software

This software allows you to correct the pointing of your OTA exactly to the target you select, saving time with alignment and, many times, without the target being visible on the screen.  Plate-solving software looks at where your mount thinks it is pointed, takes a picture of the sky and determines from its databases exactly where your mount is pointed, and, if necessary, moves the mount the precise fraction of a degree needed so that your target is precisely centered in the field of view,  Two popular examples of this software include ASTAP and Astro-tortilla.

• ASTAP
  • Link to site: ASTAP, Astrometric Stacking Program http://www.hnsky.org/astap.htm.
  • ASTAP  is one of many powerful, freeware packages of plate-solving software.  I can also stack, annotate, and view deep-sky FITS files.  The author is Han Kleijn, who resides in the Netherlands and provides frequent updates, enhancements and support.  The software runs on Linux, MacOS, Raspberry Pi, and Windows platforms.  The recommended hardware is exceeded by the needs of SharpCap.  In addition to the software, a database of stars must be used, either down to 17th magnitude, or a much larger file down to 18th magnitude.
  • Compared to other plate-solvers, ASTAP is fast, but requires more stars, about 30, to solve.  If the FOV is very small, then other plate-solvers may be necessary on something like a C8 at native focal length and a small sensor camera.  When combined with planetarium software even one-star alignment will allow reliable GoTo from the computer. See the tutorial for installing ASTAP at the bottom of this page: https://www.hnsky.org/astap.htm.
• Astro-Tortilla
  • Link to site: Astro-Tortilla plate-solving https://sourceforge.net/projects/astrotortilla/.
  • Astro-Tortilla is a good fallback whe ASTAP fails to plate-solve. Frankly, it seems to take a bit longer to do the same thing, but it’s great as a backup plan. Here’s a good tutorial for setting it up: https://www.lightvortexastronomy.com/tutorial-setting-up-and-using-astrotortilla-for-plate-solving.html.