IPS Observations in China: Past, Now and Future Lijia Liu National Astronomical Observatories, Chinese Academy of Sciences (NAOC) (Given by Mario M. Bisi, STFC RAL Space)

Outline 1. IPS study in China 2. Future development of IPS in China

IPS study in China China began IPS study in the1990s IPS theory study: Y. H. Qiu, X. Z. Zhang, P. Z. Ye et al. IPS observation: NAOC (BAO)

IPS with MSRT Since 1990s 9m, 28 telescopes Frequency: 232MHz Additive mode Equivalent aperture 47m X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001 MSRT : Miyun Synthesis Radio Telescope

IPS with MSRT X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001

C48 raw data (a) and power spectrum (b) Raw data Power spectrum IPS with MSRT

The Retirement of MSRT The degradation of radio environment in Miyun Station The construction of a new radio telescope MSRT was retired early this century IPS observation was ceased for several years

IPS with 25 m in Urumqi First SSSF IPS observing station in China Diameter : 25m Wavelength: 18cm Sampling interval: 0.25ms Integration interval: 10ms

IPS with 25 m in Urumqi Key Parameters of IPS Observations with the 25m Radio Telescope Performed in 2008 at UAO L. J. Liu et al,,RAA,2010,10,6,

IPS with 25 m in Urumqi Characteristic spectrum of the 18 cm receiver at UAO before and after filtering. L. J. Liu et al,,RAA,2010,10,6,

Spectrum Processing Pre- processing Display Data Flow chart for data processing Receiver frontend of the telescope (IF output: 5-500MHz) 0-40dB Step Attenuator Amplifier Filter （ CF：420MHz，BW：100MHz） Radiometer Data Acquisition software Flow chart for data acquisition IPS with 25 m in Urumqi

Date: Parameters ： AR=1.2 ， α=3.1 ， V=400km/s Fitting spectrum 3C Jy 0.23AU L. J. Liu et al,,RAA,2010,10,6, IPS with 25 m in Urumqi

IPS with 50m in Miyun Observing frequencies(MHz) UHF( 327/611) S/X(2300 ， 8400) The only SSDF IPS observing station in China Serving the Chinese Meridian Project

Technical Data of the Telescope X. Y. Zhu et al, RAA,2012,12,8, IPS with 50m in Miyun

Front-end of IPS observation system. X. Y. Zhu et al, RAA,2012,12,8,

Data acquisition system IPS with 50m in Miyun

(a):IPS spectrum of observation data from 3c237b on September 27, 2011 ( Red line is the theoretical fitting curve). (b)Normalized Co-spectrum(NCS) between the pairs of radio frequencies 2300/8400 in MHz.Scales are logarithmic for frequency and power density (2dB per division) and linear for NCS. X. Y. Zhu et al, RAA,2012,12,8,

1. IPS study in China 2. Future development of IPS in China

Future development of IPS in China 25 m in XAO The most efficient radio telescope in China, hard to apply 50m in Miyun Under take the Lunar Project at the meantime, IPS observation can only be a part time job

Future development of IPS in China IPS group in JLRAT, NAOC

Future development of IPS in China Build special IPS telescope Research new low frequency receivers Development of digital back-end Perfecting data processing method Strengthening international cooperation

Thank you!