Donghao Liu

Data processing for 5-element experiments of Chinese Spectral Radioheliograph

The Chinese Spectral Radioheliograph is under construction in Mingantu Observation station of NAOC, and some experiments have been carried out by 5-element system which has been established in May 2010. This paper described overall system of 5-element briefly and showed some data processing results included observations of weather satellite, GPS satellite and solar.

The error analysis between the measurement and original solar radio polarization degree

The MingantU SpEctral Radioheliograph(MUSER)is comprised of 100 antennas, which is a solar-dedicated radio interferometric array in centimetric and decimetric wave range. This radio heliograph will be optimized to carry out imaging spectroscopy of the Sun with high spatial resolution, high time resolution and high frequency resolution simultaneously. We use MUSER-I and MUSER-II to observe the Sun and get the right and left circularly polarized signal, then calculate the polarization degree of the source. The relationship between the original polarization degree of the Sun and the observed polarization degree is drawn in this paper. The error is less than 10%. So we can use the measured data of the observed polarization degree to represent the original polarization degree of the Sun.

A plan for two-element solar radio spectra-interferemeter

Solar radio observation is still an important, in some situation the unique tool to obtain the solar emission details for solar radio physics study as well as for space weather forecaster. In this paper, based on the existing 2-20m diameter parabolic antenna in Ming-An-Tu Observing Station in Inner Mongolia, a new plan for a meter spectra interferometer is introduced, which will have good performance with high frequency resolution and high dynamic range and sensitivity, and will be working in the frequency band from long meter to decimeter wavelength.

Antenna system characteristics and solar radio burst observations

University of Chinese Academy of Sciences 10049Abstract Chinese Spectral Radio Heliograph (CSRH) is an advanced aperture syn-thesis solar radio heliograph, developed by National Astronomical Observatories,Chinese Academy of Sciences independently. It consists of 100 reflector antennas,which are grouped into two antenna arrays (CSRH-I and CSRH-II) for low and highfrequency bands respectively. The frequency band of CSRH-I is 0.4-2GHz and forCSRH-II, the frequency band is 2-15GHz. In the antenna and feed system, CSRHuses an Eleven feed to receive signals coming from the Sun, the radiation patternwith lower side lobe and back lobe of the feed is well radiated. The characteristics ofgain G and antenna noise temperature T effect the quality of solar radio imaging. ForCSRH, measured G is larger than 60 dBi and T is less than 120K, after CSRH-I wasestablished, we have successfully captured a solar radio burst between 1.2-1.6GHz onNovember 12, 2010 through this instrument and this event was confirmed throughthe observation of Solar Broadband Radio Spectrometer (SBRS) at 2.84GHz andGeostationary Operational Environmental Satellite (GOES). In addition, an imageobtained from CSRH-I clearly reveals the profile of the solar radio burst. The otherobservational work is the imaging of Fengyun-2E geosynchronous satellite which is as-sumed to be a point source. This data processing method indicates that, the methodof deleting errors about dirty image could be used for processing other surface sources.Key words: Reflector antenna :Noise Temperature : Eleven antenna : Low crosspolarization : Aperture synthesis1 INTRODUCTIONIn solar radio observations, the Sun exhibits a variety of large dynamic phenomena in differentfrequencies. At the same time, it transmits constant energy to the Earth (Takano 1996). These

An image simulation for Chinese spectral radio heliograph in the decimeter wave range use CASA

The Chinese Spectral Radioheliograph (CSRH) will observe the Sun over a wide range of radio frequencies (0.4-15GHz) and make high time, space and frequency resolutions images of the Sun simultaneously, in order to address the energy release, converter and transmission processes in the solar atmosphere by mapping the solar radio emissions at dm-cm wave range. In this paper, we describe the imaging capabilities of a spiral wideband solar heliograph CSRH-I array operating at 0.4-2GHz which is capable of obtaining solar disk images at 30 ms time resolution. We use CASA (the Common Astronomy Software Applications) to map the entire sun at radio wavelengths and present simulations using models based on the Nobeyama RadioHeliograph (NORH) and the Solar Dynamics Observatory Atmospheric Imaging Assembly observations (SDO/AIA) EUV data, processing them through CSRH-I array (0.4-2GHz) and comparing with the actual images.

Baseline measurement for Chinese spectral radioheliograph

The Chinese Spectral Radioheliograph (CSRH) is a solar-dedicated synthesis aperture telescope. The maximum baseline length determines the high resolution of synthetic aperture. With its antenna array aligned in a shape of triple-spiral arms spread in an area of about 10 square kilometers. The measurement precision of CSRH tri-spiral antenna array baseline is one of the key factors for CSRH image quality. In this paper, the method of geodetic surveying and astronomical interferometry used to obtain the 3D coordinates of different antennas is introduced. The results will be verified by observing the radio source [1-3].

Solar physics with Chinese Spectral Radioheliograph

It is important to have imaging - spectroscopy over centimetric-decimetric wave range to address fundamental processes in the solar eruptive phenomena. The Chinese Spectral Radioheliograph (CSRH) is a solar-dedicated interferometric array with frequency from 0.4GHz to 15 GHz. There are 40 antennas with 400MHz to 2 GHz, and 60 antennas with 2 GHz to 15 GHz in this array. CSRH-I and CSRH-II, which include antennas, receivers, and correlators have already been established. This paper introduced the system, progress and current status of CSRH.

CSRH-II analog receiver system stability designing and testing

Analog receiver is one of the key parts of the Chinese Spectral Radioheliograph (CSRH). Analog receiver CSRH-II is used to amplify, transmitting and down converting the solar emission signal from 2GHz to 15GHz. Its system stability is much important for achieving the best quality solar images. CSRH-II system specifications set high requirements for the analog receiver systems stability designing and testing. In this paper, CSRH-II analog receiver system specification requirement, designing and testing will be discussed and presented.