ansvr - local plate solver for Windows

ansvr is plate solving software that works just like the online plate solving service, but uses an instance of the plate solver on your Windows PC, no internet connection required.

ansvr was originally developed to work with Sequence Generator Pro, but any application that uses can use ansvr in place of nova. Several imaging applications now work with ansvr including AstroImageJ, ACP and PinPoint.

Application developers: information about adding ansvr communication to your software application is here: ansvr developer notes.


  1. Download the ansvr installer: ansvr-setup-0.22.exe.      [ChangeLog]    [Windows XP Info]
  2. Run the installer
  3. Click Next or choose an alternate install location:
  4. Click Next or choose an alternate Start Menu folder name:
  5. Click Next or choose an alternate port number [more info] for ansvr:
  6. Click Install:
  7. Wait for files to extract. The progress bar will look like it is stuck in the middle for a long time. Be patient, it will finish eventually...
  8. Click Finish. You can leave both boxes checked.
  9. Now you will download the astrometric index files that you need for your setup. Select the files you need and click Start. The files are very large (increasingly so for the narrower FOV indexes) and can take a very long time to download. You can select a custom folder location for the index files by clicking the Folder button.
  10. Progress of the download is in a separate window. Close the window if you need to cancel the download. Next time you run the index file downloader, progress will resume where it left off.
  11. Confirm that ansvr is running by opening the Ansvr Settings item in the Windows Start menu
  12. A page like this will open in a web browser window with the ansvr settings. If you see this page, ansvr is running. The setup program puts an icon into the Windows Start Menu Startup folder to automatically start ansvr whenever you log in, so ansvr will always be available.
  13. If you want to watch the ansvr log file, Click Watch Ansvr Log in the Start Menu folder to open a window viewing the log file. You can close the window when done. Ansvr will not be affected by closing the window; you can still do blind solves regardless of whether the window is open or not.
  14. At this point ansvr is installed and available for plate solving. Consult your imaging application's documentation for how to configure it to use ansvr for plate solving. SGP users can continue with the instructions below.

SGP configuration

  1. Configure SGP to use the local solver. Open the Control Panel:

    Select the Plate Solve tab, and click Blind Settings. Select ANSVR.

    In older versions of SGP ( and earlier) you need to copy and paste the following value into the End Point setting:

  2. Now test a plate solve: open an image in SGP, right-click, Plate Solve, Blind Solve
  3. Solved!

Windows XP Compatibility

The most recent version of ansvr is based on a version of cygwin that is not compatible with Windows XP. You can still use ansvr on Windows XP by running an older version of the installer
  • Install ansvr-setup-0.18.exe, the most recent version that was compatible with XP
  • After the installation is complete, select Check for Ansvr Updates from the Start menu Local Solver folder. This will update the ansvr script only, keeping the cygwin installation at the XP-compatible older version.

Port number selection

In some cases there may be another application running on the PC that is already using the default ansvr port number, 8080. If you have trouble solving frames and the ansvr log file says "can't setup server: Address already in use", try re-running the installer and selecting a different port number. Some good ports to try are: 8011, 8012, 8013, 8014, 8081, 8082. The actual port number choice does not matter, just as long it it does not conflict with some other application.

Getting Help

You can get help with ansvr by posting on the Main Sequence Software forum, or you can contact me directly:
andy DOT galasso AT gmail DOT com

Andy Galasso