In the previous article I discribe low noise amplifier for the 21cm band. Today I wanna show you construction of the dish antenna where this amplifier can be used.Continue reading “Dish antenna for the amateur radioastronomy”
21 cm band also known as Hydrogen line is one of the important bands in radio astronomy.
Please read this wikipedia article if you not familiar with Hydrogen line.
Nowadays even radio amateurs can observe this signal from the outer space, thanks to modern hardware.
One of the most important part of the any receiver is antenna and input stage. Typically input stage is some kind of the amplifier with extremely low noise and high gain due to weakness of the space signals.
In this article I want to describe simple and cheap amplifier for the first stage of the receiver.
To control speed and rotation direction of the DC motor we need some type of the motor driver, one of the most popular schematic is H-Bridge. For the low current and voltages we can use some integral solution like L293D and so on. But if we need more power and reliability we have to build some custom H-bridge using mosfet transistors. This type of the transistors requires careful and proper driving itself. One of the most popular integral solution for driving mosfets is IR2110 from Infineon.
In this article we will discuss how to use this IC to build powerful DC motor driver.
This is a third part of the Allsky cycle.
Please read previous articles to get complete information about this project:
This time I will show my utility and script for shooting night sky and processing of the images.
In the previous article I’m started to describe my Raw2Fits converter. It was a brief note about GTK user interface development.
Now I wanna talk about LibRaw library. This is a great library for reading RAW files obtained from digital photo cameras (CRW/CR2, NEF, RAF, DNG, and others).
Take a look at the LibRaw project web page and official documentation.
I highly recommend to always use latest stable release from this site instead of precompiled version from Linux distros.
This is a second part of the Allsky cycle and I want to describe powering and protection of this device.
Please read first part to get basic information about this project.
Allsky (or weather) camera is one of the most important part of the modern observatory.
It’s very important to monitor sky condition during night observations, especially when observatory is remote controlled or should be fully automatic. Different vendors provides different solution. But all they are share the same problems: very high prices, lack of autonomy (PC is required) and lack of useful sensors like a temperature, sky temperature and so on. So, to build complete system you need: camera itself, PC, weather station, cloud sensor. Full price and complexity of this system is very high.
But this not a Jedi path, right?
With this article I’m starting the cycle of the materials dedicated to fully autonomous device, based on Raspberry PI. This device contains two cameras and a lot of sensors.
There are popular and quite cheap amateur telescope mounts from different vendors: Sky-Watcher, Celestron and so on.
Most of that mounts contains motors and some controller schematic. User can control this devices in different ways. One way is to use mount’s handcontroller, other way is connect to computer and use some software to control and guide the telescope. Such connection can be made through special adapters (often called eqmod). Technically this adapter is just some kind ot serial converter, RS232 to UART (TTL) or USB to UART.
Here I’m describing a very reliable and simple adapter with galvanic isolation that I was developed and made.
FITS – is an open standard defining a digital file format useful for storage, transmission and processing of scientific and other images. FITS is the most commonly used digital file format in astronomy. Unlike many image formats, FITS is designed specifically for scientific data and hence includes many provisions for describing photometric and spatial calibration information, together with image origin metadata. (Wikipedia (c)).
Most of the astronomical software and hardware produces and working only with FITS files .
But there is a big amount of astrophotographers and amateurs astronomers (actually not all is really amateurs 🙂 ) who using only modern DSLR cameras and shooting in RAW format.
Modern DSLR cameras can be used for serious science, like searching for variable stars or astrometry of some objects. But only way to do that – convert RAW files to the FITS format for future processing in a astronomical software.
I wrote a little program that solves this problem and allow easily convert files in a batch mode.
In this article i want to describe in details how it works.