VRAD system configuration

1
VRAD system configuration

• Yusuke Kono and
• SELENE VRAD group
• The Graduate University for Advanced Studies
• National Astronomical Observatory, Japan

2
VRAD(VLBI RADio source)
Rstar
QSO
Measurements of angular distance between R-star,
V-star and quasar by differential VLBI.
Vstar
Moon
Differential VLBI
Earth
VLBI stations
3
Four Carrier Waves from VRAD
Relay satellite
VRAD satellite

• Carrier 2212MHz
• Carrier 2220MHz
• Carrier 2287MHz
• Noise 8456MHz
• (Bandwidth60kHz

• Carrier 2212MHz
• Carrier 2220MHz
• Carrier 2287MHz
• Carrier 8456MHz

S-bandThree waves , X-band One wave.
4
Sampler and RecorderltVRADgt

• SRTP-station
• SUN WorkstationAD board
• 200ksps,6bit
• OSsolaris
• Recording on 8mm tape 8 hour
• Consumption of tape 1 / day
• Graphical User Interface
• Easy correlation on WS or PC
• Time referred to NTP server

• Low pass Filter
• Cut off frequency 70kHz

5
The back of the SRTP-Station
Signal 4ch
For making Time codes, Tone signal, 1pps and
connection to internet are needed.
10MHz tone
1pps pwgt10µs

• LAN, Internet,
• NTP Server

Adjusting WS inner clock
6
Sampler and RecorderltQSOgt

• K4 Back-end
• QSO gt1.2Jy (S-band)
• QSO gt0.8Jy (X-band)

• DIR-2000

7
Correlation software

• VRAD
• correlation on software

• QSO
• NAOCO
• (New Advanced One unit Orrelator),
• developed at the NAO

Phase difference
8
Observation of Lunar Prospector
Original software
Lunar Prospector of NASA S-band beacon signal
QSO 3c273B
NAOCO
Kashima-Mizsawa baseline Residual fringe phase
variation connected by fringe rate
9
Conclusion
I would like to come to China to set up the
SRTP-station again.
Thank you very much.
10
Conclusion
VRAD global network