Step-Scanning Interferometer with Digital Signal Processing

1993 ◽  
Vol 47 (9) ◽  
pp. 1345-1349 ◽  
Author(s):  
Christopher J. Manning ◽  
Peter R. Griffiths
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Digital Signal Processor ◽  
Modulation Frequency ◽  
Depth Profiling ◽  
Digital Signal ◽  
Scanning Interferometer ◽  
Ft Ir ◽  
Lock In ◽  
Signal Processor

A novel step-scan FT-IR spectrometer incorporating a digital signal processor for demodulation of the detector signal is described. The potential advantages of this method of signal processing are discussed and illustrated. The instrument is based on a commercial cube-corner interferometer which has been modified by replacement of the drive motor with a stepper motor-micrometer and piezoelectric transducer combination. The interferometer retardation is feedback controlled by a 486–50 personal computer, which also controls the digital signal processor and collects spectral data. More than one phase modulation frequency can be imposed simultaneously, allowing for a multiplex advantage in photoacoustic depth profiling. Digital signal processing allows for simultaneous demodulation of multiple frequencies which would normally require several lock-in amplifiers. Data that illustrate the feasibility of these concepts are presented. The suitability of this instrument for double-modulation step-scan FT-IR measurements such as polymer stretching and electrochemically modulated step-scan FT-IR is also discussed.

Digital Signal Processing for Step-Scan Fourier Transform Infrared Photoacoustic Spectroscopy

1997 ◽  
Vol 51 (4) ◽  
pp. 453-460 ◽  
Author(s):  
David L. Drapcho ◽  
Raul Curbelo ◽  
Eric Y. Jiang ◽  
Richard A. Crocombe ◽  
William J. McCarthy
Keyword(s):  
Signal Processing ◽  
Fourier Transform ◽  
Digital Signal Processing ◽  
Phase Modulation ◽  
Modulation Frequency ◽  
Digital Signal ◽  
Sampling Depth ◽  
Ft Ir ◽  
Infrared Photoacoustic Spectroscopy ◽  
Additional Hardware

A software-based digital signal processing (DSP) method using the data system processor has been developed to demodulate the photoacoustic responses of a sample to the fundamental phase modulation frequency and its harmonic frequencies (up to the ninth harmonic) in step-scan FT-IR photoacoustic measurements, without the use of any additional hardware. The DSP algorithm and its sampling depth multiplexing advantages are compared to conventional hardware demodulation. Comparison of results from the DSP method to those from hardware demodulators are shown at both the phase modulation frequency and the harmonics, and application of the DSP method to step-scan photoacoustic measurements with phase modulation is discussed as it applies to obtaining depth profile information in heterogeneous materials.

scholarly journals Application Analysis of Digital Signal Processor DSP in Logging Instrument

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
Jie Lian
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Digital Signal Processor ◽  
Large Scale ◽  
Digital Signal ◽  
Large Scale Integration ◽  
Scale Integration ◽  
Evolution Of Science ◽  
Development And Evolution ◽  
Signal Processor

In today's world, the development of economy has led to the continuous development and evolution of science and technology. Computer technology and large-scale integration technology have been well developed and applied, followed by the technology of digital signal processing DSP production and application. In the field of logging, the application function of this technology plays a key role. It not only allows the imaging logging technology to be further developed, but also enables fast and accurate processing of downhole signals. Therefore, among many logging tools today, digital signal processing DSPs have been widely used, and their functions have been fully utilized. This paper analyzes the application of signal processor DSP in logging instruments. It is hoped that it can play a reference role in the good application and development of logging instruments.

Polarization Modulation Fourier Transform Infrared Spectroscopy with Digital Signal Processing: Comparison of Vibrational Circular Dichroism Methods

2001 ◽  
Vol 55 (11) ◽  
pp. 1435-1447 ◽  
Author(s):  
Jovencio Hilario ◽  
David Drapcho ◽  
Raul Curbelo ◽  
Timothy A. Keiderling
Keyword(s):  
Signal Processing ◽  
Circular Dichroism ◽  
Digital Signal Processing ◽  
Digital Signal ◽  
Vibrational Circular Dichroism ◽  
Polarization Modulation ◽  
Rapid Scan ◽  
Ft Ir ◽  
Lock In ◽  
Circular Dichroïsm

Digital signal processing (DSP) has been implemented in a step-scan FT-IR spectrometer in a modification that enables processing of high-frequency polarization modulation signals. In this work, direct comparison is made between vibrational circular dichroism (VCD) spectra measured on the same instrument, with the same samples, under the same conditions, using this new DSP method and a conventional rapid-scan technique (employing a lock-in amplifier for demodulation). In this initial test, both techniques generated high-quality VCD for solution phase, rigid chiral molecules such α-pinene and camphor. Noise and reproducibility of known spectral features, as well as enhancing signal measurability and discrimination, were used as criteria for the selection of optimal DSP measurement parameters. Both DSP and rapid-scan VCD methods produced qualitatively reasonable spectra for biologically related molecules such as poly-γ-benzyl-L-glutamate, poly-L-proline, and duplex RNA homopolymer. In most cases, the DSP method had a slight signal-to-noise advantage based on standard deviations of the noise trace data over the rapid-scan measurement, but the final results did depend on the details of the data collection and the phase correction methods inherent in both methods.

The NEC μPD7720 Digital Signal Processor — A Laboratory-Based Case Study

1984 ◽  
Vol 21 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Trevor J. Terrell ◽  
Robert J. Simpson
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
Digital Filter ◽  
Digital Signal Processor ◽  
Design Method ◽  
Digital Signal ◽  
Single Chip ◽  
Signal Processor

The concepts of single-chip digital signal processing are presented via a student-oriented tutorial/laboratory case study. This involves the design of a highpass digital filter using the first-difference design method and its implementation using the NEC μPD7720 Signal Processor.

Design of Virtex-7 FPGA-Based High-Speed Signal Processor Carrier Board

2015 ◽  
Vol 719-720 ◽  
pp. 534-537
Author(s):  
Wen Hua Ye ◽  
Huan Li
Keyword(s):  
Signal Processing ◽  
Digital Signal Processing ◽  
High Speed ◽  
Processing System ◽  
Digital Signal ◽  
Signal Processing System ◽  
High Speed Adc ◽  
High Speed Data ◽  
Processor Speed ◽  
Signal Processor

With the development of digital signal processing technology, the demand on the signal processor speed has become increasingly high. This paper describes the hardware design of carrier board in high-speed signal processing module, which using Xilinx's newest Virtex-7 FPGA family XC7VX485T chip, and applying high-speed signal processing interface FMC to transport and communicate high-speed data between carrier board and daughter card with high-speed ADC and DAC. This design provides a hardware implementation and algorithm verification platform for high-speed digital signal processing system.

Design of Radar Echo Signal Processing System Based on FPGA and DSP

2013 ◽  
Vol 391 ◽  
pp. 555-559
Author(s):  
Yu Chen ◽  
Qiong Qiong Xu ◽  
Jian Wei Leng
Keyword(s):  
Signal Processing ◽  
Digital Signal Processor ◽  
Processing System ◽  
Digital Signal ◽  
Echo Signal ◽  
Signal Processing System ◽  
Wave Signal ◽  
Design Scheme ◽  
Radar Echo ◽  
Signal Processor

This paper presents a kind of design scheme about radar echo wave signal processing system based on digital signal processor (TMS320C6416) and FPGA (EP2C8Q). This scheme is used to timely monitor radar echo data and then calculates it. Distance of target items can be obtained by this method. Take advantage of flexibility and easy-processing complicated data of FPGA and DSP, we promote property of this system to a large extent

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