Source Code

There are two varieties of source code here. The first variety are 'modular' routines that can be used as fundamental building blocks for writing your own scripts. The second are code fragments that demonstrate techniques for solving certain problems or providing certain features.

Many of the items on the Software page are also available as complete open-source applications.

All software and source code samples available from this site are licensed under the GNU General Public License except where otherwise specified. Please note that this license requires that if you release your modified versions, you must release them as free software. Contact me and I will be happy to host your modifications here if you don't have a way of serving them.

Modular Source Code:

This section seeks to provide a set of routines that do specific jobs that are widely used at robotic and remote observatories. All the routines can be put into the same script and will work together with little or no tweaking.

The origin of this section is my own script-writing activities. I've put together a couple dozen scope-control scripts since 1999, mostly for friends who wanted to do something a bit differently than the other guy. It became much easier to identify "standard" activities (such as "take an image" and "slew the telescope to the target") and write "standard" routines to accomplish these activities, and incorporate these as "modular" building blocks into the new scripts. Where necessary, they could be altered and tweaked to get the desired performance without having to re-invent the wheel every time I sat down to write a new script.

The idea here is to give you some raw material to work with when devising your own scripts. You can use whatever tools are needed, change them however you need to change them, and otherwise tinker with the operation of a script without having to know a lot about writing source code and without having to conceive everything from the ground up. You can use as much or as little as you want from the collection modular routines.

There are certain limitations:

• These routines assume certain variables and objects are available globally, so you've got to handle the dimensioning as you see fit. This is described on the Headers & Conventions page.
• Some of the source code here is pretty "clunky" in its performance. There are elegant and compact ways of coding, and then there are bloated and counterintuitive ways. I've occasionally chosen bloated and counterintuitive. However, I've used comments liberally.
• Since this source code is being made available under the GNU General Public License, if you release your alterations to this code, you must release it as freeware. You do not have to release your modifications of this code at all, of course. I'm not going to make you fill out invasive forms and sign a contract, so just download whatever you want - upstanding folks will do the right thing, thieves and scum-suckers will do whatever they want.
• All of this source assumes you are running ACP, PinPoint, MaximDL/CCD, Kepler, NOVAS, and Widgets, because these tools seem to have become more or less standard amongst the most successful robotic observatories. Unfortunately, ACP 1.3 and Maxim 2.1 are currently assumed; we will have routines here for the new versions before mid-January.

The modules:

• Headers & Conventions - This is documentation for the objects and variablenames (or function names) that are assumed by the modular routines. Most objects are assumed to be global; a few are created at run-time from within the functions and subroutines as needed. A certain number of conventional names are assumed; these can be either values returned from functions, variables that you define locally by adding appropriate code to these functions, or values returned from like-named functions. These conventional names are defined in this document as well.
• TakePicture (function) - This function is called in order to take an image with the CCD camera. It accepts an exposure duration and a filename for the resulting image; it takes the picture, displays progress in the ACP console, saves the image, and returns a boolean to indicate success or failure.
• AimCamera and SpiralSolve (functions) - Two functions that work together to aim your telescope precisely at an object. This function assumes that you are going to take a pointing exposure of your target, solve it, and if necessary, update the position of your telescope for greater pointing accuracy. The SpiralSolve is invoked only if your telescope points relatively far from where you wanted, and is intended to put things back on track in such an emergency.
• GetGuideStar (function) - This function selects a guide star from a user-selectable star catalog. It makes sure the guide star is bright enough, and selects the closest available star so that the target is decentered by the smallest possible amount.
• Log, Logtext, and Sayit (functions) - These are the three logging functions that are used by all other routines.

Source Code Fragments and Examples:

Spiral Search (zip file) - Occasionally an image will be taken that isn't pointed precisely. In these cases, a straightforward attempt to solve the image in PinPoint will fail, simply because the image isn't within the star matching area. This function provides a spiral search algorithm that will hunt thruogh an ever-increasing checkerboard of possible fields for a solution to the FITS image. It can be plugged into or adapted to larger scripts. Requires PinPoint 3+. This is an adaptation of one of Bob Denny's subroutines.

Spiral Search - a better way of doing the spiral searching described above. Requires PinPoint 3.

Guide Star Acquisition (zip file) - This is a subroutine that autoguides an image. It picks a guide star from a user-specified star catalog, rather than searching for one randomly. Requires PinPoint 3+ and Maxim DL/CCD 2.1+. By John McClusky.

Waiting for Camera to Cool - This is a short code snippet that demonstrates a straightforward way to have a script wait for a CCD camera to come to a predetermined temperature before continuing with the execution of the script. Requires Maxim 2.1+ but is definitely adapatable.

Using a Non-Integrated Guider - When using a guider that is distinct from the imaging camera - say, an ST-6 guiding an AP8 imager - the guider can be timed out or crashed when the imager is downloading. This code sample deminstrates a simple VBScript technique that avoids the problem, by suspending the guider just before the image is downloaded. Written for Maxim DL/CCD 2.1+ and ACP 1.3+, but is adaptable.

Robotic Observatory home page.