1. FRB Backend First Light
XAO, PU
Pei Xin, Li Kejia, Nie Jun, Nuer

2. FRB(Fast Radio Burst)
A fast radio burst (FRB) is a transient celestial radio pulse lasting only a few milliseconds, and thought to be of extra-galactic origin, though this notion is contested.
D. R. Lorimer and others analyzed archival survey data and found a 30-jansky dispersed burst that occurred in 2007, less than 5 milliseconds in duration.
In 2010 there was a new report of 16 similar pulses from the Parkes radio telescope which were clearly of terrestrial origin, but in 2013 four pulse sources were identified that supported the likelihood of a genuine extragalactic pulsing population.
An observation in 2012 of an FRB in the direction of Auriga(御夫座) in the northern hemisphere using the Arecibo radio telescope has confirmed the extragalactic origin of fast radio pulses by an effect known as plasma dispersion.
Victoria Kaspi of the McGill University also confirms the initial estimate of 10,000 FRB's per day over the entire sky.

3. FRB Searching Project Kejia Li, Peking University
XAO cooperation with Peking University
= Pulsar Backend + Real-time Searching
XAO PU

4. Pulsar Backend Design
斯托克斯参数输出格式

5. Data Format

6. Programming

7. System Test Plan 1.Pulsar sources select 2.Observation prepare
source_name, period, flux, DM, Dec&RA
2.Observation prepare
hardware: S/X band receiver, 1pps, 10M, 10GbE Link
software: antenna control, data record
3.Backend
integration time, bandwidth, fft point, number of channels, gain, transmission rate, data_output
4.Post processing
data format transform
pulsar processing: sigproc

8. Pulsar sources select Source name Period DM S1400 (mJy) RA DEC W10B
26.833
203
03:32:59.368
+54:34:43.57
31.4 J
34.468 23
06:30:49.404
-28:34:
119.7 J B
4.864 32
11:36:03.247
+15:51:04.48
41.8 J
11.456 13
20:48:35.640
-16:16:
99.3 J B
141.26 19
21:13:24.307
+46:44:08.70
152.8 J B
70.857 17
21:57:01.849
+40:17:45.986
114.2 J
94.591 12
23:21:55.213
+60:24:30.71
153.7

9. Hardware Prepare B A
10M
1PPS

10. 10GbE Link

11. Software Prepare Single radio sources tracking mode
Filterbank data transform
SIGPROC processing

12. ROACH Backend Configuration
Corr package, for interacting with BEE2s and ROACHes
gain, fft_shift, acc_len, period, payload_len…

13. S-IF1
Filter
8bit 13dB Dynamic Range
S-IF2
Strong
RFI
No Filter

14. Saturation, Decrease RFI

15. Observation Jan. 1 2015 – Jan. 6 2015 Pei Xin, Yan Hao
Nanshan 25m, S-band Receiver

17. Data Processing & Result
Bandpass
MHz
BW: MHz
MHz

18. Profile J
1.024ms integration
5min observation
32bit, 1IFs

19. Profile J
1.024ms integration
5min observation
32bit, 1IFs

21. J
0.512ms integration
2.5min observation
32bit, 1IFs

22. J
1.024ms integration
5min observation
8bit, 4IFs

25. J
S1400: 19mJy
0.512ms integration
2.5min observation

26. J
S1400: 17mJy
1.024ms integration
10min observation

27. 100S Fold
300S Fold
600S Fold
1200S Fold
Signal
FRI

28. 1.024ms integration 20min observation
Dropped Ratio: 43/ =0.0035%

29. Conclusion Result should be correct Time resolution: 1/200M=0.005us
Min. Integration Time: 2.56us
Need L-band tests
Need more hardware support
New 10GbE module solve package loss problem
Could expand to pulsar timing, polarization mode
Software optimization plan

30. Thank you !