DSAP Studio (Digital Signal Analysis and Processing Studio) is a tool for digital signal analysis and analysing digital filters. It allows a discrete signal or its spectrum to be read in a specific format, Fourier or inverse Fourier analysis of the signal, and digital filtering. With DSAP Studio software you can set up your desired filter parameters and generate easily according to filter coefficients, export the filter coefficients in a form ready to copy/paste to your embedded system or other code. DSAP Studio helps you in digital signal processing (DSP) and digital signal filtering (DSF). Various window functions rectangular, triangular, Hamming, Blackman, Hann, Flat-Top, Welch can be used in analysing and processing. Spectrums can be shown in logarithmic form and then frequency scale will be logarithmic as well in decades or octaves.
DSAP Studio
Import of signals or spectra recorded directly from the oscilloscope is supported:
Rohde & Schwarz R&S RTB, RTM, RTA and RTC series.
From DSAP Studio the user can export data of signals and spectrums to import them to oscilloscope (again supported oscilloscopes are R&S RTB, RTM, RTA and RTC series).
Reading signal or spectrum data (points) from other sources is possible also. Data has to be in csv formatted file, where the field separator is a comma. Numbers can be in scientific (exponential) notation, the decimal separator is a decimal point. To load data from such files you should set:
for the first data line: line number in file (count starts from 1),
for horizontal data (time, frequency): column number where is data , unit (s, Hz), factor,
for vertical data (voltage, current, relative): column number where the data is, unit (V, dBm, A), factor.
A factor other than 1 is needed when the source of raw data does not take into account probe attenuation and other settings.
DSAP Studio is avalable on Microsoft Store
The user can specify the frequency values of the digital filter and analyze the effects of the filter on the input signal accordingly.
The user can generate a signal from several components of different shapes, frequencies and amplitudes and process it with the desired filter. Possible filter types are low pass, high pass , band pass, band stop and arbitrary filter. Spectrum of arbitrary filter can be set by multiple pairs of frequency-attenuation. The app sorts points by frequency and shows values with metric prefix (1000 is shown as 1k).
DSAP Studio can use all of your computer processing power as it is possible to set it to use parallel computing (multi-threading). By parallel computing of FFT or inversed FFT or convolution or FFT convolution you can save a lot of time.
From version 3.5 it is possible to use level in signal and spectrum analysis. You can set a specific level for the signal or spectrum and analyse filtered transient samples. This is very useful when the signal or spectrum has more samples than the display can represent in which case samples are decimated or averaged to the overall level. In this way you can easily find transient points on horizontal (time or frequency) scale and zoom in (using zoom at cursor feature). Zoom can be set deeper than 1:1 as well, for example 1:0.1 (result will be 10:1 but app shows 1:0.1). When analysing longer signals or spectrums the time saved will be huge.
The app sets level value to middle by default, but you can edit this. The app opens a table with transient samples as well. This table can be hidden/shown at will. To remove a level (line) and table, enter an empty value for the level (delete content of value filed on level form).
Tips
The main view is divided into 3 parts: input, filter and output view. Users can switch views on and off to get a wider view of a particular part. When the view is switched off it keeps its data and when switched on shows it.
The user can change the color of graphs separately (right-click on mouse). It is also possible to hide/show specific graphs.
Hovering the mouse pointer shows the data of the signal or the spectrum on that point.
Zooming in/out is possible with a) the mouse wheel, zoom step is proportional to the part of graph visible and the horizontal position of the pointer. With right-click zoom 1:1/full is possible; b) context menu Zoom (mouse right-click) which opens Zoom options:
Signal scales (vertical, time) are always linear. Spectrum scales can be set to linear or logaritmic. When set to logaritmic, the amplitude scale gets the option for absolute (Voltage V) and relative (decibels dB or dBm relative to 50 Ω) scales.
Numerics are shown in specified significant numbers (can be modified in settings, default is 5, in the trial version it is between 1 and default, in the full version it is between 1 and 10) and when the value is in the range between 10^-24 to 10^24 the according metric prefix is used (from y - yocto to Y - yotta).
Vertical scale shows two values: amplitude and phase, amplitude in V, dB or dBm and phase in rad.
DSAP Studio easily handles files with sizes in Gigabytes, for example the R&S RTA series oscilloscope can produce export files with 200 Msamples. The size of an export file with 100Msamples is about 3GB. The size of a corresponding file from DSAP Studio app with full FFT data is about 12GB. Of course there are limits. As DSAP Studio digital signal processing and digital filter construction software is capable of parallel computing, long signals and spectrums will be easy to process.
The app checks imported spectrums and if it finds it to be real-part then it converts it to complex spectrum.
Trial version of DSAP Studio software allows the use of all features but saves to file only the 4 first values: signal, spectrum, filter and digital filter coefficients data.
Summary of features:
Importing signal or spectrum data from source (.csv file).
Generating composite signal and filter in DSAP Studio app.
Padding and cutting of signals at will.
Generating filter spectrum for low-pass, high-pass, band-pass, band-stop or arbitrary form filters.
Modeling of digital signal processing.
Application of digital filter to input signal.
Export of filter coefficients.
FFT analysis.
Inverse FFT analysis.
STFT (Short Time FFT) analysis.
Input signal and filter response signal convolution.
FFT convolution.
Logarithmic scale for logarithmic spectrum.
Serial or parallel processing.
List of updates (30 Nov 2022 version 3.9):
Spectrum frequency scales in logarithmic form (decade or octave).
Options for cutting and padding signal and filter response signal.
Short-time Fourier transform (STFT or STFFT).
Window functions. In trial version only Hamming, in full version rectangular, triangular, Hamming, Blackman, Hann, Flat-Top, Welch window functions.
Histograms of signal and spectrum graphs.
Signal or spectrum amplitude level can be set and analysing transient samples.
Can read other signal and spectrum data when first row position and column data positions, units and multipliers are set,
Reading out both voltage unit (V) and current unit (A),
Graphs can be zoomed with mouse wheel (was available earlier) or via context menu (zoom options),
Graph zoom status added to zoom info,
User can change number of significant numbers between 1..5 in trial, 1..10 in full version,
Calculations and save data in single (float) precision also (in Full version only),
User can change draw order of graphs,
Free trial possible,
Check for updates,
Parallel computing for FFT, inverse FFT, convolution and FFT convolution,
User can select parallel or serial computing,
Zoom left or middle added to graphs flyout menu (removed, zooming has been moved to zooming options),
Zoom 1:2 added to graphs flyout menu (removed, zooming has been changed),
Reset button added to signal and filter generator forms,
Saving user settings,
Reset to default settings,
DSAP Studio website address added to About form,
Added Tips form,
Option in Settings to save all the data or for oscilloscope,
Option to save as .csv file,
Save filter data as filter coefficients only,
Multiple instances of DSAP Studio app can run,
Symmetrical padding of input signal,
Symmetrical padding of filter response signal,
Cutting of input signal,
Cutting of filter response signal,
Symmetrical cutting of input signal,
Symmetrical cutting of filter response signal,
Generate filter response spectrum moved to Generate menu,
Generating of input signal (multicomponent),
Windows of Input, Filter response and Output can be switched on/off,
Settings: number of significant numbers can be adjusted,
Settings: max number of signal components can be adjusted,
dBm scale in vertical scale,
Removed limitations on file size,
Large integers presentation,
Status info to signal and spectrum import,
Status info to signal and spectrum saving,
Load output signal,
Load output spectrum,
FFT of output signal,
inverse FFT of output signal,
Pad filter response signal,
Stretch input signal,
Save filter response signal,
Save filter response spectrum,
Save output signal,
Save output spectrum.
Your feedback is welcome!
Enno Lepvalts
enno@aovalgus.ee