1. ISAS/JAXA Tracking station

2. Usuda Deep Space Center Diameter 10m –AE 44% expected Feed & Receiver –Ka-band Trx < 50K expected –cooled LNA –Tsys 140 K (fine condition)

3. Feed DIP TX- AMP U/C D/CLNA H-Maser DDS O/EE/O O/E LO O/EE/O U/C DDS LO D/C LO DEMPD FMT CLK GEN LO Mark5B Cooled VSOP-2 Ground System (Based on halca method) PC OBS Simulator CMD/MON Freq, Phase Controller 40.0 GHz 37.5 GHz 100MHz (±2MHz) 100MHz 1100MHz 100MHz (±2MHz) 500 MHz 5,900MHz 7,000MHz 26,000MHz 4,500MHz 7,000MHz 6,500MHz 100MHz 500MHz 100MHz10MHz VSI-H 1PPS 100MHz 400MHz Freq, Phase Control 26,000MHz Software Spectro- scope Ether Freq, Phase Control Network Ether 7,000MHz EtherGP-IB Antenna RoomOperation Center U/C 1,000MHz LO FIFO Carrier track

4. Feed DIP TX- AMP U/C D/CLNA H-Maser O/EE/O O/E LO O/EE/O LO D/CDEMPD FMT LO Mark5B Cooled VSOP-2 Ground System (w/o Doppler Comp.) PC OBS Simulator CMD/MON Freq, Phase Controller 40.0 GHz 37.5 GHz 100MHz 500 MHz 7,000MHz 26,000MHz 4,500MHz 7,000MHz 6,500MHz 100MHz 500MHz 100MHz10MHz VSI-H 1PPS 26,000MHz Software Spectro- scope Ether Network Ether 7,000MHz EtherGP-IB Antenna RoomOperation Center LO FIFO

5. Doppler compensation needed? Related Matters –Band mismatch –PLL Loop stress –Phase characteristics of onboard instruments –Correlator capability –System construction cost

6. Band mismatch Doppler shift: ~1MHz (f=40GHz, rr=7km/s) Band-mismatch: 126 MHz (128 – 2 MHz) Degradation of SNR ： 0.99 (√126/ 128)

7. PLL Loop stress Relation between Doppler rate and PLL : Natural angular frequency of second order loop(rad/sec) : Rate of change of angular frequency (rad/sec2) : Phase error of Phase Lock Loop, threshold ( ~12deg.)

8. Phase characteristics of instruments Phase fluctuation dφ by df : Easy estimation –H up (f)- H down (f)=2πfτ –Group delay characteristicsτ: ～ 1nsec –Phase fluctuation dφ ～ 0.36 deg (df~1MHz) Phase characteristics measurements needed before launch

9. Data Storage Storage Terminal with VSI –Mark5B (Haystack) –K5-VSI (NiCT) –Clock fluctuation compensated by FIFO? Corrlator interface –VLBA correlatorMark5 –ENV correlatorMark5 –EAVN* correlatorMark5, K5, VERA terminal *EAVN (East Asia VLBI Network)

10. East Asia VLBI Network Correlator Korea-Japan Joint VLBI Correlator (KJJVC) –KVN and NAOJ KVN, VERA, JVN, VSOP-2 Seoul 16 stations Data buffer Data rate –Max. 8 Gbps/st

11. Summary UDSC 10m antenna is expected to VSOP- 2 GTS Doppler compensation system depends on cost. Several VSI storages are available –Mark5B is better for operational easiness at three correlators.