Specifications of Deajeon Correlator
Item |
Description |
Observation Array Constitution
- Number of Stations
- Number of Inputs for a station
- Sub-array Constitution
- Total number of Correlation
|
- (max.) 16 stations
- (max.) 4 inputs
- 4+12 stations / 8+8 stations
- (max.) (16 Auto
- + 120 Cross-) × 4 sets
|
Observation Requirements
- Observation Frequency
- Largest Baseline Length
- Maximum Baseline Velocity
- Frequency Resolution
- Dual Polarization
- P-cal Detection
- Maximum Data Output Rate
|
- (space VLBI)45GHz, (Others)130/86/43/22GHz
- ± 36,000 km (±0.12 sec)
- 7.5 km/sec
- 53.3m/sec (for 22GHz Observation)
- Yes, for only 8 stations at once
- Yes
- 1.4 GBytes/sec
|
Input Data Profiles
- Digitization
- Quantization Levels
- Interface
- PDATA Acceptance
- Data Rate
- Input Format
|
- 1024 Msamples/sec × 2 bits/sample
- 4 levels as "00" < "01" < "10" < "11"
- VSI-H (32parallels data, 1PPS, VALID, PDATA)
- As "format A" of ADS-1000
- 2Gbps / 1Gbps
- Wide Band Mode (1Gsps x 2bits)
- Narrow Band Mode (1Gbps/512Mbps Multi Data Streams)
- Narrow Band Mode2(2Gbps Multi Data Streams)
|
Input Data Control
- Rate up Data Acceptance
- Stream Selection & Multiplexing
|
- Yes, Double rate(form 1Gbps) / Quadruple rate(from 512Mbps)
- Yes
|
Delay Compensation & Fringe tracking
- Delay Prediction Parameters
- Delay Compensation Period
- Fringe phase quantization
- Fringe phase applying range
- Word length of Fringe tracking
|
- τg , τg’, τg” and τg’’’ (for 1.024 sec)
- According to FFT segment border
- 2π/16 radian
- every 1samples
- 16bits, 2's complement
|
Special Analysis
- FFT points
- Word length
- Window modulation
- Delay residual(△w) compensation
- Scaling
- Cancellation DC-offset
- Frequency Offset Addition
- Re-quantization
|
- 256k / 128k / 64k / 32k / 16k / 8k points ("k" means "×1,024")
- Fixed point 20+20 bits (real + imaginary)
- Yes, 4 kinds as "Rectangular" / "Hamming" / "Hanning" / "Blackman"
- Yes
- Yes
- Yes
- Yes
- Fixed point 8+8 bits (real + imaginary) : The Output are only USB or LSB
|
Correlation & Accumulation
- Word length of Correlation
- Station Data Switching
- Word length of Accumulation
- Integration Period
- Frequency binning / Frequency binning setting points
- Points of Correlation Output Data
- Correlation Output Data Interface
|
- Fixed point (8+8) bits → (15+15) bits
- Yes
- Fixed point (32+32) bits (real + imaginary)
- 25.6msec/51.2ms/102.4ms
- 10.24sec(102.4ms unit)
- Yes, 1 / 2 / 4 / 8 / 16 / 32 / 64 / 128 / 256 channels bin.
- Yes, (for each 512-points of output)
- 8,192-points(for each correlation). Each points are result of binning
|
Control Interface |
10Gbits Ether × 4 ports, TCP/IP, Based on VSI-S |