한수지 51(2), 178-186, 2018 Original Article Korean J Fish Aquat Sci 51(2),178-186,2018 어군에의한광대역음향산란신호의시간 - 주파수분석을위한 chirp 데이터수록및처리시스템의성능특성 이대재 * 부경대학교해양생산시스템관리학부 Performance Characteristics of a Chirp Data Acquisition and Processing System for the Time-frequency Analysis of Broadband Acoustic Scattering Signals from Fish Schools Dae-Jae Lee* Division of Marine Production System Management, Pukyong National University, Busan 48513, Korea A chirp-echo data acquisition and processing system was developed for use as a simplified, PC-based chirp echosounder with some data processing software modules. The design of the software and hardware system was implemented via a field-programmable gate array (FPGA). Digital signal processing algorithms for driving a singlechannel chirp transmitter and dual-channel receivers with independent TVG (time varied gain) amplifier modules were incorporated into the FPGA for better real-time performance. The chirp-echo data acquisition and processing system consisted of a notebook PC, an FPGA board, and chirp sonar transmitter and receiver modules, which were constructed using three chirp transducers operating over a frequency range of 35-210 khz. The functionality of this PC-based chirp echo-sounder was tested in various field experiments. The results of these experiments showed that the developed PC-based chirp echo-sounder could be used in the acquisition, processing and analysis of broadband acoustic echoes related to fish species identification. Key words: Chirp data acquisition and processing system, Broadband acoustic echoes, Time-frequency analysis, Fish species identification 서론,., (Fässler et al., 2009)., - - (air chamber), contrast. echo (Foote, 1980; Stanton et al., 2010)., echo., echo,, echo (Simmons et al., 1996; Lee et al., 2014; Lee, 2014; Lee et al., 2015)., echo,, (Fernandes, 2009)., chirp,, chirp. FPGA (Field-Programmable Gate Array) (Digilent, 2011; Gądek et al., 2014) chirp echo,,,. https://doi.org/10.5657/kfas.2018.0178 Korean J Fish Aquat Sci 51(2) 178-186, April 2018 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received 8 March 2018; Revised 7 April 2018; Accepted 9 April 2018 *Corresponding author: Tel: +82. 51. 629. 5889 Fax: +82. 51. 629. 5885 E-mail address: daejael@pknu.ac.kr Copyright 2018 The Korean Society of Fisheries and Aquatic Science 178 pissn:0374-8111, eissn:2287-8815
Chirp 데이터수록및처리시스템의성능특성 179 재료및방법 Chirp echo 데이터수록및처리시스템의설계 chirp echo FPGA (Digilent, 2011) Nexys 2 board (Spartan- 3E FPGA 1200K, Xilinx, USA). FPGA VGA (video graphics array), RS232 (recommended standard 232), USB (universal serial bus), PS/2 (personal system/2), LED (light-emitting diode),, PMOD (peripheral module), 5 V, 50 MHz (clock generator). GPIO (general purpose input/output),, 2 6 (pin) PMOD I/O FPGA trigger, TVG (time varied gain), chirp 2 1., 1 POMD I/O chirp echo FPGA. Chirp echo FPGA (1) chirp echo chirp, Fig. 1 chirp Airmar chirp (B256L, B265H, B75M) (Lee, 2017). (1) f 0 chirp, 2at+f 0 (instantaneous frequency)., - chirp (T ) (B),, 2a(=B/T ) (Cowell and Freear, 2010). s(t)=e j2 (at 2 +f 0 t +c) (1), chirp rate, chirp f 0 20 khz, 2a 200 khz chirp.,, chirp echo. 2. (dual beam) (side scan sonar). Chirp echo chirp 1 2,, TVG, A/D. A/D 12 bit ADC7476 (Texas instruments, USA) 1 MHz. 35-75 khz (Lee, 2017; B265L, Airmar), 75-130 khz (B75M, Airmar) 130-210 khz (B265H, Airmar) Fig. 1. Schematic diagram of the chirp data acquisition system for measuring and analyzing the broadband acoustic echoes from fish schools. The system consists of an FPGA (field-programmable gate array), two receiver modules composed of two channel TVG (time varied gain) amplifiers and A/D converter modules, a chirp signal generator implemented on a PC, a transmitter module composed of power amplifier and transformer, and three chirp transducers. The software modules for accomplishing the input/output, control and signal processing were created specifically for this application. The communication with FPGA hardware is managed by a USB-based protocol and associated USB interface. ADC, analog-to-digital converter; BPF, bandpass filter; DAC, digital-to-analog converter MOSFET, metal oxide semiconductor field effect transistor.
180 이대재, 35-210 khz. chirp FPGA 1.0 ms, 20-220 khz chirp. (transformer) chirp chirp., echo 2 B265LH 1,., 75-130 khz echo 2 B75M., (Lee, 2017). Chirp echo 신호의시간 - 주파수분석 SPWVD (smoothed pseudo wigner-ville distribution) chirp echo (Shui et al., 2007; Han and Kim, 2010)., SPWVD Table 1. Specifications of hardware modules consisting of the chirp data acquisition and processing system developed in this study Hardware modules FPGA Chirp transmitting module Chirp receiving module Chirp transducer Specification Xilinx Spartan-3E FPGA 1200K gate Four 12-pin Pmod interface VGA, PS/2, USB2 and serial ports Hirose FX2 connector 16 MB PSDRAM &16 MB strataflash ROM 50 MHz oscillator Chirp output pulse signal 20-220 khz Output power 100 W Chirp pulse duration 1.0ms TVG gain 96.8 db (0.48 db step) ADC 12 bit 1 MHz sampling Pre-amp gain 24 db Bandpass filter 25-85 khz (L), 100-220 khz (H) DAC 16 bit 5V output Airmar B265LH and B75M, Self-made transducer (Lee, 2017) Notebook PC Dell inspiron (2.53 GHz, windows 7, core i5) FPGA, field-programmable gate array; VGA, video graphics array; TVG, time varied gain; ADC, analog-to-digital converter; DAC, digital-to-analog converter.. SPWVD WVD (wigner-ville distribution) (Imberger and Boahsh, 1986), SPWVD (Blaska and Sedlacek, 2001; Dong and Cui, 2012) SPWVD x (f,t)= g(t)*( - + h( )[x(t+ ) x*(t- )] e -j d ) (2) 2 2., * t convolution, g(t) (time smoothing window function), h( ) (frequency smoothing window function). (2) convolution, SPWVD x (f,t)= - + h( ) - + g(s-t)[x (s+ )x*(s- )] ds e -j d (3) 2 2. (Shui et al., 2007), SPWVD x (f,n)= h(m) g(k) x(n+m+k) x*(n+m-k)e -j4 fk (4) m =- k =-, m k t index, x(n) echo. (4) echo -, SPWVD g(k) h(m),. chirp echo (4) echo -,. 현장실험에의한 echo 응답특성의측정및성능평가, chirp 2015 6 23 2016 2 4 ( 1,737 ) 5. chirp 2015 6 23 5,., chirp 2016 2 4 5, [tungsten carbide sphere with 6% cobalt binder (WC), 40 mm] echo
Chirp 데이터수록및처리시스템의성능특성 181 -., echo 2016 2 4 5 chirp. 결과및고찰 Chirp echo 데이터수록및처리시스템의성능특성, chirp echo Fig. 2 Fig. 3. Fig. 2 (a) FPGA 2 TVG 1,. Fig. 2 (b) echo., Fig. 3 2015 6 23 5, echo,. Fig. 3 chirp echo, 3., 2 chirp echo, echo,, 2., 2 chirp split beam, (Lee and Shin, 2001; Lee and Lee, 2010; Lee and Lee, 2011; Lee, 2011). Fig. 3 2 chirp. Fig. 2 chirp Fig. 3 20-220 khz,., 0-40 db, TVG no-tvg, 10 log (r), 20 log (r), 30 log (r), 40 log (r). Chirp echo, 255 ping 1., FFT window.,, chirp echo cursor., chirp echo - window., chirp echo Fig. 2. Photographs of the chirp data acquisition and processing system developed in this study. (a) An FPGA (Field-Programmable Gate Array) board connected to two receiver modules and a transmitter module. (b) A completed PC-based chirp echo-sounder composed of a chirp transceiver, a PC-based data processing system and an additional data monitoring system. SPWVD (4) - echo. chirp - echo., - echo (Lee, 2015a; Lee, 2015b; Lee et al., 2016; Lee, 2016). 교정구의시간 - 주파수 echo 응답특성, chirp
182 이대재 Fig. 3. Layout for the software module of the chirp data acquisition and processing system developed in this study. (WC, 40 mm) echo, Fig. 4. Fig. 4 2016 2 4 5, echogram. 5 9.5 m,. Fig. 4 chirp 4.0 m, chirp 3 m( 7 m) echo,. Fig. 4 7 m 9.5 m echo echo. echo. Fig. 4 chirp echo - chirp sonar,, Fig. 5 Fig. 6. Fig. 5 Fig. 2 chirp,, 35-75 khz echo. Fig. 5 (a), (b), (c) 2 -, (d) 3 - contour., Fig. 6,, 130-210 khz echo. Fig. 5 Fig. 6 (a), (b), (c) 2 -, (d) 3 - contour. Fig. 4 echo,,
Chirp 데이터수록및처리시스템의성능특성 183 Fig. 4. An echogram for the low frequency channel (35-75 khz) measured from a WC (tungsten carbide sphere with 6% cobalt binder) sphere (Dia. 40 mm) suspended just below the chirp transducer to test the functionality of the developed chirp data acquisition and processing system. Fig. 5 Fig. 6. echo., echo,, chirp 1.0 ms, 20-220 khz chirp, 0.1 ms, 35-75 khz - echo., chirp -., echo, Fig. 4 echo 0.7 ms, 100-210 khz., chirp echo -., 3 echo contour Fig. 6 (b) Fig. 5. Time response waveform (a), frequency spectrum (b), time-frequency image (c) and 3D contour plot (d) of the broadband echo signal from a 40 mm WC (tungsten carbide sphere with 6% cobalt binder) sphere suspended at about 3 meters depth on the beam axis just below the chirp transducer operating over the range of 35-75 khz.
184 이대재 Fig. 6. Time response waveform (a), frequency spectrum (b), time-frequency image (c) and 3D contour plot (d) of the broadband echo signal from a 40 mm WC (tungsten carbide sphere with 6% cobalt binder) sphere suspended at about 3 meters depth on the beam axis just below the chirp transducer operating over the range of 130-210 khz.. Fig. 5 Fig. 6 chirp rate, 400 khz/ms, 157 khz/ms, echo. FPGA chirp - chirp. 35-75 khz,, echo.,,, chirp - echo. 어군의시간 - 주파수 echo 응답특성, chirp echo, Fig. 7. Fig. 7 (a) 5 echogram, echo., Fig. 7 (b) Fig. 7 (a) 25 sonar ping chirp echo, Fig. 7 (c) Fig. 7 (b) echo 2 -. chirp
Chirp 데이터수록및처리시스템의성능특성 185 Fig. 7. Expended echogram (a), chirp echo waveform (b) and time-frequency image (c) for the broadband echo signal from seabed. The echo signal from fish aggregations near the seabed was acquired over the frequency range of 130-210 khz in the Busan northern harbor, Korea. The time-frequency image show that it is possible to separate and resolve the two echo signals if their time components for the echo signals from seabed and fish do not overlap in the time domain. echo.,., Fig. 7 (c) echo echo -., Fig. 7 (c) echo - -., -, echo.,. chirp,,,. 사사 (2017 ). References Baska J and Sedlacek M. 2001. Use of the intergral transforms for estimation of instantaneous frequency. Meas Sci Rev 1, 169-172. Cowell DMJ and Freear S. 2010. Separation of overlapping linear frequency modulated (LFM) signals using the Fractional Fourier Transform. IEEE Transactions on UFFC 57, 2324-2333. http://dx.doi.org/ 10.1109/TUFFC.2010.1693.
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