# Questions tagged [linear-chirp]

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25 questions
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34 views

1answer
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### What is meant by LFM (Linear Frequency Modulation) waveform?

I m a newbie in radar experiment on which currently i m working, and I m trying to understand the transmitted waveform which is LFM (Linear Frequency Modulation), but unable to interlink between the ...
1answer
316 views

### chirp signal - Frequency spectrum characteristics

I am confused with my own intuition of the frequency response of a chirp signal. In this case, the chirp signal is a frequency modulated signal with initial frequency starting at 100 Hz and ending at ...
3answers
693 views

### Matched filter loss due to frequency offset

I'm working with a pulsed radar signal which uses linear chirp pulses. I perform pulse compression by applying a matched filter of the simulated chirp waveform and recording the location and power of ...
2answers
160 views

### Decoupling two signals where one is a delayed version of the other

I have a signal $y(t)$ that consists of the sum of two signals where one is a time delayed version of the other. $y(t) = x(t) + x(t-t_{d})$ $x(t)$ is known but the time delay $t_d$ is not. I ...
4answers
3k views

### Pulse Compression(Chirp) SNR Gain

I've created both single tone signal and a LFM chirp signal with same pulse duration and cross correlated both of them with their own(matched filter). Peak points of both results were same as expected ...
1answer
167 views

### how fast can you sweep sinewave

I am asking specifically about discrete sound signal, non dithered 16 bit 48000 Hz pcm/wav format. My question is, how fast can you change sinewave frequency before it distort? Imagine a frequency ...
1answer
774 views

### The frequency response function (FRF) fails to detect the antiresonance of a system

I am trying to identify a vibrational systems by computing the frequency response function (FRF) of the system when a chirp signal is applied to its input. After comparing the FRF computed and the ...
2answers
742 views

### Can anyone explain how does CZT (Chirp Z Transform) really help in 'spectral zooming'?

I found some explanation alongwith the Matlab Code here: http://prod.sandia.gov/techlib/access-control.cgi/2005/057084.pdf but I can't figure out, without a good example, why would this result in ...
1answer
610 views

### FMCW SAR chirp return from target modelling

I have to Model a chirp signal that was return from a Distance D from target and then multiply with the reference transmitted signal. Which will give me beat frequency signal and then fft to get the ...
1answer
1k views

### Basic question about chirp signal

Suppose I generate chirp signal with the following python code: ...
2answers
875 views

### Spectrogram of a chirp and its FFT

This question follows from an answer to this other question: Conceptual question on FFT and chirp signal I wrote a code starting from the spectrogram to compare it with the FFT result. ...
3answers
7k views

### Conceptual question on FFT and chirp signal

If I take the FFT of a sinusoid I will get a plot whit all the energy of the signal concentrated at the sinusoid frequency. But what happens if I have a signal in which the frequency keeps changing?(...
1answer
299 views

### “chirp” with arbitrary period

Say you have a linear chirp, which is a bit like a sinusoid with a gradually increasing period, but instead of the linearly increasing period, could you pick an arbitrary value, like the red line in ...
2answers
787 views

### Finding linear chirp parameters from a low quality spectrogram, possibly with image processing techniques?

tl;dr: What is a fast way to get the equation of this line? I have to extract the "line of best fit" from this data (shown below), and many others like it (so I need a robust method). It is a a ...
2answers
763 views

### How can the FFT be used for estimating linear chirp parameters?

Consider a linear chirp signal, i.e. $f(t) = f_0 + kt$, where $f_0$ is the starting frequency, and $k$ is the chirp rate. After applying an FFT, how would I find the starting frequency and chirp rate?