Three Arduino Projects for Astronomers
http://www.newark.com/arduino Astrophotography is now well supported by a variety of Arduino hardware and software options for the best, most eye-popping images of the heavens, in particular in this episode, “photo stacking”, “equatorial mount”, and “auroral indicator”, are the focus. Not only has astrophotography delighted us with pretty pictures of night skies, but it contributes to the field of astronomy by its ability to record new stars and galaxies invisible to the human eye. This is achieved by long time exposure.
The night sky in the city is nothing like the night sky in remote areas. The best quality astrophotography would be achieved far off in the wilderness, so that all other light sources do not interfere with the images of the stars. To further assist in producing perfect, clear images a technique called “photo stacking”, is employed.
For “photo stacking”, take as many pictures as possible using a camera with a good telephoto lens. A telescope is not required. Adding a micro-controller such as Arduino, controls the function and motions of the camera for the best results. The tracking motors are controlled remotely by an Arduino board. So you are taking a variety of images of the same item and then to make the final image sharp and clear, you are going to merge the images to produce detailed pictures of the star fields and related phenomena like galaxies.
You then need an advanced editing program solely for stacking images, such as Deep Sky Stacker. This is also called focus stacking. What it does is removes visual noise. Your photos are downloaded onto the computer and any unwanted and unnecessary artefacts are removed, such as aeroplanes or clouds. The program also aligns the photos to ensure that stars are at the same place before doing dark field substractions. By taking all the mean values of each pixel, the resulting photo has all the details without any of the visual noise. “Photo stacking”, can be seen as a set of pictures with different focus points, which you load and take the focus point of each, then merge.
The second Arduino project is building an “equatorial mount” for long exposure photos. The long photographic exposure time required to really get into deep space, results in star trails with a static tripod. This movement difference because of your static tripod, stops you capturing more faint details and making that next new discovery! An “equatorial mount” spins with the Earth, keeping the stars in sharp focus and getting the details that are often more difficult to capture, like The Milky Way. The equipment has to be rotated in the opposite direction to the Earth to keep the stars centred.
An “equatorial mount”, can be mounted on a sturdy tripod and programmed with Arduino, controls the motion and allows your camera to track across the sky, connected via a serial connection to your computer or laptop with an Ascom driver to software like Skymap, for further control and selection of areas to photograph. This can also be used for telescopes.
For the third Arduino project aimed to enhance your astrophotography, there is the “auroral indicator”, which gives a visual warning of when the Northern Lights are likely to be visible so that you never miss good displays of Northern Lights activity. Arduino is the hardware heart of the project. Wire up your LEDs to the Arduino pins and use resistors appropriate for your LED display, which will show the current level of auroral activity. Use a breadboard first to ensure everything is going to the correct pins, and that resistor values are correct.
There are three main components to the “auroral indicator”, the PHP web scraping script, processing script and Arduino script. The web scraping script gathers information from the geomagnetic activity index you use. There is the Wing KP predicted geomagnetic activity index among others. It gives an hour’s notice of Northern Lights activity. The processing script allows the Arduino to use a system of lights to display information, like red for high activity, green for low activity, white for go, go, go it’s all happening, and blue for moderate. With the “auroral indicator” you won’t miss out on the best opportunities for the best images.
With the simplicity of Arduino and its small powerful control unit, fantastic results in astrophotography come within the reach of the amateur enthusiast. All these kits are available at www.newark.com/arduino for the three projects for astronomers involved in astrophotography, which are the “photo stacking”, the “equatorial mount”, and the “auroral indicator”.
There are so many tools and projects to build with Arduino software as well as the electronics and that will be covered in the next episodes. You can build and control almost anything that you can think of – every astronomer’s dream.