5
votes
Radar signal processing flow chart
Part of your misunderstanding comes from the fact that there are many ways in which the radar signal processing chain is implemented. Depending on the type of radar, targets of interest, hardware, etc....
- 2,336
5
votes
Accepted
Absolute value based AM envelope detection viewed in the frequency domain
$\DeclareMathOperator{\sgn}{sgn}$
The modulating signal in AM is
$$s(t) = C + a(t)\text,$$
where $a(t)$ is the (audio) amplitude, and $C$ is a constant so that $s(t) \ge 0 \;\forall t$. (Otherwise, ...
- 29.6k
4
votes
Pulse duration detection
That looks a lot like an exponentially decaying sinusoid. What you are primarily interested in is the decay rate. Where it ends would then have to be defined as when it reached some threshold level.
...
- 7,520
3
votes
Best DSP algoritms for ultrasonic background noise cancellation
One way to do this is to look at modeling your signal:
$$
x[n] = x_h[n] + x_n[n]
$$
where $x_h$ is the hissing sound and $x_n$ is the noise.
If you can say that $x_n$ is modeled as:
$$
x_n[n] = \sum_{...
- 25.2k
3
votes
Probability of False Alarm versus SNR
Hi: In statistics we call that the probability of type I error ( rejecting when true ) and type II error ( accepting when false ). The way it's done there is that, once you make an assumption about ...
- 1,107
3
votes
How detect signal from noise?
I have dealt with similar problems before. Probably the first you need to know is how does the noise spectrum look like.
First approach (mostly empirical): I see your signal of interest (SoI) is a ...
- 530
3
votes
CFAR Detectors and Interference
The "best" detector is a highly subjective subject, and there is (in my opinion) not a definitive answer here. I work in radar processing and I've used everything that you've mentioned in one form or ...
- 853
3
votes
Accepted
Detect low power DSSS-BPSK signal
Without disagreement to Dilip's valid comments, this is to show the corner case as to when you can detect the presence of DSSS. This is not demodulating the data but detecting the presence of a ...
- 48.8k
3
votes
Accepted
where we use estimation and detection in communication system?
Don't worry too much about defining these terms too precisely, because they are used in many contexts with slightly different meanings.
In very general terms, "estimation" is the calculation ...
- 14.9k
3
votes
Accepted
Detection problem with extra noise observation. Does the extra observations help with detection?
$$y=y_1 + \alpha y_2=x+(1+\alpha)n_1+\alpha n_2 \tag{1}$$
As $n_1$ and $n_2$ are iid $\mathcal{N}(0,\sigma^2)$, you have now the new Gausian noise $\mathcal{N}(0,\nu^2)$ where $\nu^2=\left((1+\alpha)^...
- 6,080
2
votes
Should I Use a High Pass Filter (HPF) or Low Pass Filter (LPF) to Enhance the Features for Image Splicing Detection?
Since you're after a filter which emphasizes abrupt changes you should use High Pass Filter.
The issue is you'd be also sensitive to noise.
Hence one way to do it is to apply High Pass Filter on ...
- 19.3k
2
votes
How does the PASCAL VOC challenge evaluate the task of object detection?
The detection task is: Given an image $I$, does it contain a sub-image $S$ (or an object $S$)?
There are several things that can happen:
$I$ contains $S$ and the detector says $I$ contains $S$
This ...
- 25.2k
2
votes
how to detect short pause in a speech with noise?
You can use Voice Activity Detector(VAD) for detecting the pauses in speech and there location(and duration). if your input signal is not very noisy and noise is not varying much you can use a fixed ...
- 687
2
votes
Are radar resolution and detection capabilities not very tightly related?
I'll provide a slightly different perspective. Detection is usually measured against the noise and/or clutter statistics, so you end up with a detection probability which is a function of Signal to ...
- 2,841
2
votes
Are radar resolution and detection capabilities not very tightly related?
If you can detect the target separately , you have resolved the targets. If you resolved two targets, you have detected them too.
In general you are totally right, radar can detect targets and in ...
- 388
2
votes
Are radar resolution and detection capabilities not very tightly related?
Resolution is (usually) referred to as the ability to distinguish two closely separated returns, not targets.
The distinction is how far along the processing chain of the radar you are, resolution, ...
- 185
2
votes
Accepted
Face Recognition: Simplistic Explanation on PCA Eigenface Algorithm
The step-to-step explanation in Eigenface seems quite clear to me.
A covariance matrix is like an high-dimensional extension of the variance, which is computed by removing the average from your only ...
- 31.7k
2
votes
Note Recognition Software
This is an old question, but one that comes up often enough that I thought I'd add this resource that I just ran across: open source software (in Swift) that might be useful to others interested in ...
- 121
2
votes
How to determine the symbol rate of a 2-FSK signal?
One approach could be to perform an FM-detection step (e.g. an atan2() operation followed by a first-order difference) to transform the waveform to measurements of ...
- 24.5k
2
votes
If I line in the sound from a video game console, can I detect when a sound is played?
Theoretically you could separate your desired sound by ICA method or other blind source separation methods from the background music, then design a matched filter by your separated sound. The matched ...
- 1,328
2
votes
How to reliably detect the state (opened or closed) of sliding doors from a statically-positioned video stream
To better deal with occlusions, my idea would be to separate this problem into detecting if:
the 1st door is in position fully opened (1)
the 1st door is in position fully closed (2)
the 2nd door is ...
- 131
2
votes
Detect a Frequency Change in a Step Wise Frequency Chirp
There are many way to tackle this:
Time - Frequency Analysis
Classic choice would be a spectrogram but probably a Fourier Synchrosqueezed Transform would do a better job (Have a look at even more ...
- 19.3k
2
votes
Accepted
AWGN continous time channel + colored noise
To solve this problem, it is necessary to understand what exactly is meant by $\langle R, \psi_1 \rangle$ and $\langle R, \psi_2 \rangle$. These are the outputs of correlators or matched filters and ...
- 20.2k
2
votes
Accepted
Interpolating Filter for Quadrature Detector with one ADC
Q1: Which Matlab calculation is right
The interpolation filter is done after the zero stuffing as that process of inserting zeros creates images in the resulting spectrum, so this filter would be at ...
- 48.8k
1
vote
How to choose good features for my machine vision application?
The choice of the algorithm is dependent on the constraints of the application. If you are able to collect (or find) thousands of labeled images covering many possible scenarios, then the popular ...
- 5,465
1
vote
finding frequency range and dominant frequency of a stored signal
To detect the fundamental frequency of your signals, you can use self-correlation. The maximum of the self-correlation will correspond to your fundamental frequency (the second maximum, as self-...
- 684
1
vote
How to reliably detect the state (opened or closed) of sliding doors from a statically-positioned video stream
I think tracking motion of something like corner or handle of the window would work. Consider following procedure:
1. Track the corner of the windwo
2. If position of the corner changes more than X ...
- 1,976
1
vote
Accepted
How do spectrum analyzers detect peaks?
This is most likely related to the comparator function and the waveform.
Long story short:
...
- 10.6k
1
vote
What's wrong with this Average Magnitude Difference algorithm?
okay, i took a look at your code and at your data.
first of all, the algorithm you are using is not autocorrelation but is the Average Magnitude Difference Function (AMDF). it will give results ...
1
vote
Is image processing impacted by the lens or sensor size of the camera?
Is image processing impacted by the lens or sensor size of the camera?
Yes, since both affect the image that is processed. That was easy :)
For the purposes of object detection and tracking, does ...
- 29.6k
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