1. Automatic solar telescope

Optical part

Base of Stations is a spectroheliograph of Astronomical Observatory of Kharkov State University constructed by Barabashev and Ponomarev.

Spectroheliograph is a horizontal solar telescope. 12-centimeters objective (focal length 350 cm.) builds a image of the Sun on spectrograph slit. Base of spectrograph is diffraction grating with spectral resolution 120000. Selection of spectrum area is realized by turning diffraction grating. Camera mirror builds slit image on a CCD-photometer. For the Sun observation CCD photo-detector is located along the selection line in the first order spectrum. Scanning image is realized by coelostat clock-drive stop. Scanning the full solar disk is carried out for 2 minutes approximately.

CCD-photometer

Photometer is based on cooled one-dimensional CCD K1200CL2 (USSR) and personal computer (Korokhin at al., 1993).

Technical features of photometer are:

1. Spectral range (level 0.5 from maximum) - 0.35-1.05 m.
2. Amount of elements (pixels) - 1024.
3. Pixel size (width x length) - 12 x 24 m.
4. Size of photosensitive sections (mm) - 24.
5. Flat field distortions - < 1%.
6. Dynamic range - 1000.
9. Digitization - 14 bits.

2. Processing and data formalization subsystem

Subsystem of the data processing and data formalizations is build on the basis of program complex CyberTech <IRIS> (http://members.xoom.com/cyteg). <IRIS> possibilities to work with kits of files allow easy to execute one-type operations for all files from the kit. For digital images processing "Helios" plug-in was added to <IRIS>. "Helios" functions are described below.

2.1. Initial processing
Image of the solar disk is received at the scanning of the Sun by its own motion. Sun moves, as a rule, not perpendicular relatively spectrograph slit, and image of the solar disk recorded distorted. For this reason processing must include the following stages.
1. Correction of distortion caused by inefficacy of charge carrying between CCD cells (angular resolution increasing with the methods of spatial-frequency filtration).
2. Image form determination (coordinates of center, inclination etc.).
3. Geometric image transformation to a coordinate system, where Sun disk is a circle.
4. Taking into account of the CCD cells sensitivity variation and interference effects.
5. Taking into account of the image darkening to the edge of the disk.
6. Transformation (rotation) of the image to standard coordinate system.

2.2. Statistical and photometric analysis. Data formalization
The CyberTech <IRIS> system (with "Helios" plug-in) is used for the further analysis too.
Researcher in automatic or semiautomatic mode can define coordinates of details and special indexes of solar activity.

3. Data archiver subsystem (databank)

Processed images are adding to electronic archive (databank). At the system development it was planned that the databank would be free accessed via Internet. However in the full absence of financing we can't regularly to update our site and all the more to support Internet databank. So, we have a possibility to place images in database in the Jpeg-format only. Nevertheless, we put some of original FITS-files in database (FITS headers format). If you interested FITS-files, please contact us cyteg@astron.kharkov.ua.

4. Data transport subsystem

Data transport subsystem consists of following parts:
1. Ethernet Network (10Mbps) for transfer data inside the station.
2. Free Sub-domain on VirtualAve.Net server for databank keeping.
3. Dial-up connection to Internet for databank updating.

For regular observations and databank updating we need at least funds to lease permanent Internet connection.

[Home|^Top|<<Back]