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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
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IPS theory study: Y. H. Qiu, X. Z. Zhang,
P. Z. Ye et al.
IPS observation: NAOC (BAO)
IPS with MSRT
MSRT : Miyun Synthesis Radio Telescope
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Since 1990s
9m, 28 telescopes
Frequency: 232MHz
Additive mode
Equivalent aperture 47m
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
IPS with MSRT
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
IPS with MSRT
Raw data
Power spectrum
2000-4-12 3C48 raw data (a) and power spectrum (b)
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
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
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First SSSF IPS observing station in China
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Diameter : 25m
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Wavelength: 18cm
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Sampling interval: 0.25ms
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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,2010,10,6,577-586
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,2010,10,6,577-586
IPS with 25 m in Urumqi
Receiver frontend of the telescope
(IF output: 5-500MHz)
0-40dB Step Attenuator
Data
Flow chart
for data
acquisition
Display
Amplifier
Preprocessing
Filter （CF：420MHz，BW：100MHz）
Processing
Radiometer
Data Acquisition software
Spectrum
Flow chart
for data
processing
IPS with 25 m in Urumqi
3C345
7.1Jy
0.23AU
Fitting spectrum
Date: 2008.12.1
Parameters：AR=1.2，α=3.1，V=400km/s
L. J. Liu et al,,RAA,2010,10,6,577-586
IPS with 50m in Miyun
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Observing frequencies(MHz)
UHF( 327/611)
S/X(2300，8400)
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The only SSDF IPS observing station in China
Serving the Chinese Meridian Project
IPS with 50m in Miyun
Technical Data of the Telescope
X. Y. Zhu et al, RAA,2012,12,8, 857-864
IPS with 50m in Miyun
Front-end of IPS observation system.
X. Y. Zhu et al, RAA,2012,12,8, 857-864
IPS with 50m in Miyun
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, 857-864
1. IPS
study in China
2. Future
development of IPS in China
Future development of IPS in China
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25 m in XAO
The most efficient radio telescope in China, hard
to apply
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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
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Build special IPS telescope
Research new low frequency receivers
Development of digital back-end
Perfecting data processing method
Strengthening international cooperation
Thank you!