Presentation - Association Astrimage

Pic-astro : and if your mount finally followed the movement of the earth ?

What is it ? The sun rises in the east and sets in the west, it moves all day. On the same principle, moon, planets and stars seems to move in the sky, because of the rotation of the earth. To compensate this rotation, astronomers use motorized equatorial mount. The Pic-Astro is an electronic unit, its role is to drive stepper motors that fit this type of mount.

The Celestial rotation - Credit : Gemini observatory

The project

The Pic-Astro project was entirely developed by Arnaud GERARD. It was completely integrated to Astrimage and is one of the most solid foundations of the association. Astrimage developed and Federated documentation on this project to make it accessible to all. Pic-Astro A1 is now ordered in kit form with components of professional quality thanks to partnership with the supplier of components Gotronic and bulk orders.

Pic-Astro, the universal tracking system

Fully adjustable, Pic-Astro is able to drive any using stepper motors! Without the computer, the Pic-Astro is able to compensate the rotation of the earth alone. But the system reveals its true power when connected to a computer or his little brother Merop. It is then possible from a known star, to move the telescope automatically on any object in the sky. Pic-Astro is able to understand and follow the protocol now widely standardized LX200, it is recognized by most mapping software (Cartes du ciel, The Sky, WinStar ...) Once the target located, it can be observed but also photographed with long pose. Indeed, Pic-Astro provides guiding, either using a PC (Iris, Maxim DL, CCD soft, Astroart, ...) or manually using the buttons on the remote control or the joystick of Merop.

Pic-Astro, dare a very accurate tracking of celestial movement

Pic-Astro enable to drive all stepper motors. It is special in the way of guiding which makes him a outstanding driving system. This feature is appreciated by astro-photographers who need highly accuracy.

Indeed, Pic-Astro share each motor step in 256 micro step linearized. It offers a smooth movement while maintaining the accuracy of stepper motors. You can see the difference by yourself:

Video of a motor in 8 micro steps by steps (systems used generally) :

8MicroSteps.avi (DivX 2,2 Mo)

Video of a motor in 256 micro steps by steps with Pic-Astro:

256MicroSteps.avi(DivX 2,2 Mo)

Pic-Astro goes further than micro-steps by allowing you to linearize them with adjustments. So you can make constant and regular the trip between each micro-step, by adapting the signal command Pic-Astro to your motors. Using the micro-step system gives a daunting accuray to Pic-Astro in guiding and generally in Astro-Photography, with the accuracy of monitoring. It is, likewise, for the Goto adding the error for polar alignment.

Features

Among the features of Pic-Astro, the main ones are:

LX200 emulation protocol.
Fully adjustable speeds.
Setting motors to adapt to all types of mounts and gears.
Advanced autoguiding : optimized guiding orders treatment , adjustment and compensation of backslash.
Linearization of motors micro-steps to have rotation without vibration, or sudden movement.
Periodic error correction.
Lunar, solar, and sideral speed.

In addition to the pleasure to mount yourself the kit, you'll have a system with extraordinary performance , built for only a part of the price of commercial systems. In the case of any failure, Astrimage remain at your disposal to help you resolve it.

Evolution with ease

Pic-Astro is completely evolving. Like a computer, you can update its software simply: you just need a computer, no need for a microcontroller programmer or expensive equipment to perform this operation. Its configuration, the settings for parameters can be easily and quickly done using the same method.