The correlation process is carried out by KJCC (Korea-Japan Correlation Center) at Daejeon, Korea. Hereafter it is tentatively called "Daejeon correlator", and its basic specifications are summarized in Table 5. The Daejeon correlator can process the data stream of up to 8192 Mbps from maximum 16 stations at once. Currently, available data formats are 16 IFs X 16 MHz ("C5 mode" in the Daejeon correlator terminology) at K- band, and 8 IFs X 32 MHz ("C4 mode") at both K- and Q-bands, and 2 IFs X 128 MHz ("C2 mode"). Minimum integration time (time resolution) of Daejeon correlator is 0.2048, 0.8192, and 1.6384 seconds for both C4 and C5 modes, and the number of frequency channels within each IF is 8192 for both modes (i.e. maximum frequency resolution is about 1.95 kHz). By default, the number of frequency channels is reduced to 128 (for continuum) or 512 (for spectral line) via channel integration after correlation. One may put a special request of number of frequency channels to take better frequency resolution. The number of frequency channels can be selected among 512, 1024, 2048, 4096, or 8192. Final correlated data is provided as FITS-IDI file.
Max. number of antennas | 16 |
correlation mode | C2^{b}(128 MHz Bandwidth, 2 stream) |
C4(32 MHz Bandwidth, 8 stream) | |
C5(16 MHz Bandwidth, 16 stream) | |
Max. number of corr./input | 120 cross + 16 auto |
Sub-array | 2 case(12+4, 8+8) |
Bandwidth | 512 MHz |
Max. data rate/antenna | 2048 Mbps VSI-H(32 parallels, 64MHz clock) |
Max. delay compensation | ± 36,000 km |
Max. fringe tracking | 1.075 kHz |
FFT work length | 16+16 bits fixed point for real, imaginary |
Integration time | 25.6 msec ~ 10.24 sec |
Data output channels | 8192 channels |
Data output rate | Max. 1.4GB/sec at 25.6msec integration time |
^{a}For more details, see the following website:
http://kvn.kasi.re.kr/status report/correlator_status.html ^{b}This mode is not available for observations using NRO45 and Tianma65. |
EAVN ( East Asia VLBI Network )