# Questions tagged [spatial]

The tag has no usage guidance.

25 questions
Filter by
Sorted by
Tagged with
119 views

### Signal and Space/Time

I have been reading a couple of definitions on signal such as: Any quantity measurable through time over space or any higher dimension can be taken as a signal. And this, In the physical ...
18 views

### Multi channel signal enhancment inequality proof

Assume that $\mathbf{h}(f)$ is a spatial filter coeff vector, and $\mathbf{d}(f)$ is the steering vector. $\mathbf{\Phi_v}(f)$ is the correlation matrix of noise. How do i proof the following ...
122 views

### Use 2D FFT to replace 2D Discrete Fourier Transform (MATLAB)

I met a problem. I ran a code to implement the 2D discrete Fourier Transform, here is the code: ...
154 views

### How to calculate spectrogram from nonstationary, nonuniformly sampled signal

I have a high resolution 3D spatial signal (xy-elevation data collected via Terrestrial Laser Scan) with very nonuniform sampling (holes/shadows due to vegetation; point spread varies as a function of ...
120 views

### Are there accepted ranges of “high”, “medium” and “low” visual spatial frequency?

I have an image and have been able to quantify its power across spatial frequencies, using Python. What I am interested in doing is creating some measure of how much of the image's information is low, ...
751 views

### How to calculate the spatial frequency of an image in cycles per image

I have been attempting to calculate the spatial frequency of a colour image. I first converted it to grayscale and used a Fast Fourier transformation (fft2) that codes the quantity of each spatial ...
109 views

### How to prepare and plot unequally spaced, irregular data to a contour plot or similar with MATLAB

I've got a data set of hot-wire measurement velocity amplitudes at a given frequency bin (time data that has already been transformed to the frequency domain and I am just considering data for a given ...
662 views

### Spatial sampling frequency equation

Upon reading this microphone array tutorial, I'm stuck in the following piece: The spatial sampling frequency along the x-axis is given by $f_{x_s} = \frac{\sin \theta \cos \phi}{\lambda}$ ...
248 views

### IFFT of Microphone Array Directivity Response

I am implementing a microphone array simulation in my thesis. My prof and many documents indicates that microphone array behaves like filters in DSP but instead time-frequency domain there exists ...
728 views

### What does PSD represent in the spatial domain?

People use FFT methods to analyze topographic features in the spatial domain, such that the signal varies over (x) rather than (t). If a PSD curve characterizes amplitude versus frequency of an ...
273 views

### Calculating spatial width from power spectrum HWHM

Say I have a 1D (spatial) signal (resolution = $1000$) which is zero everywhere except from $x = 250$ to $750$, where it equals one. I ultimately want to calculate the spatial width of this signal ...
78 views

### Simulating spatial perception - with cosine wave based sound - in MATLAB

I'm trying to create cosine wave, one for the right channel and another for the left. The one on the left is to be moved in phase to simulate change to the spatial perception of the tone. A delay in ...
49 views

### Physical Interpretation of $\mathbf A$ beamforming Matrix

The directivity of an array is defined as: $$D = \frac{1}{2} \int_{-1}^{1} \lvert B_{u}(u)\rvert^{2} du$$ Where $B_{u}(\cdot) = \mathbf{w}^{H} \mathbf{v}(\cdot)$ is the beampattern of the array in ...