An Analysis of the Random-Group Data Format and a Design of the Data File Structure for a Solar Radio Heliograph

The CSRH (Chinese Spectral Radio Heliograph) is a new generation radio heliograph working in the wavelengths of centimeters and decimeters. It has entered the test stage. At this stage it is important to study error corrections, instrumental calibrations, and observational data precessing for the CSRH to facilitate its development. Efficient data storage and high-performance data processing are crucial to these studies for the CSRH. In this paper, by investigating current radio interferometers in the world and data formats supported by main-stream analysis softwares in radio astronomy (e.g. AIPS++ and CASA), we choose to analyze the widely adopted random-group format (UVFITS). We then design the structure of a random-group data file for the CSRH to store needed data, including the uv, antenna, and object-information data. We also design and test a software protocol. Our experiment shows that such a data file can be read and processed successfully by the CASA software. Our study is expected to help the development of the CSRH and benefit research of other astronomical instruments.