All Questions
Tagged with signal-processing electromagnetic-radiation
27
questions
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24
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Two-Ray Ground-Reflection Model: Understanding the Difference in Phase Offsets at the Receiver
Currently, I'm trying to understand the Two-Ray Ground-Reflection Model.
During my research, I came across the following simplification expressing the received power as follows (taken from Wikipedia):
...
- 11
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1
answer
123
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The solar spectrum on the time domain
This is the solar spectrum by wavelength:
By formula $c=f\lambda$, we can plot the solar spectrum over the frequency domain:
Then we can conduct inverse Fourier transform to transform the plot into ...
- 9
1
vote
1
answer
35
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Maximum bitrate density of a shared medium
I'm not a physicist, so my apologies if this isn't worded correctly, or if it even is a valid question.
I was recently learning how WiFi works and how the slowest devices on a channel can slow down ...
- 111
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1
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48
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Infer 3D location (Height, Latitude, Longitude) based on Signal Strength
Sorry if my question is irrelevant.
Let's consider two cases:
$1)$ Suppose that we have an Antenna and a tagged individual that can be pinged from the Antenna. Suppose that the individual is pinged ...
- 115
1
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1
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75
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Would increase the size of an antenna theoretically improve the ability to capture signals, if we allow changing the shape?
I have an argument with my friend about drone radio systems.
My assumption is this: the bigger the receiver the better reception is possible to achieve. The logic behind this is geometry: transmitter ...
- 111
1
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1
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29
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Is it possible to reveal a slight chronological change in frequency of Voyager 1 and 2 signals due to Hubble flow effect?
Is it possible to reveal a slight change in frequency of Voyager 1 and 2 signals due to Hubble flow effect? As both are about 1 light-day from Earth and as it is unbelievebly small distance compared ...
- 1,825
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2
answers
677
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Can unjammable radio communication be achieved by transmitting an error-correcting code of high-energy pulses in a secret, unpredictable pattern?
Signal jamming seems like an annoyingly simple way to sabotage a lot of interesting ideas. It has historically been used to block reception of propaganda broadcasts, and also to ruin military ...
- 75
2
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2
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231
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If radio signals attenuate when travelling through space, then what kinds of emissions are we looking for when searching for extraterrestreal life?
My understanding is that radio waves travel forever, like ripples in a pond, but attenuate with distance. They get mixed with other signals and become cosmic noise.
I'm looking at these answers, which ...
- 67
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2
answers
425
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Maximum distance between two towers for space wave propogations
Context: Space waves are a form of radio wave propagations, a space wave travels in a straight line from the transmitting tower. The problem here is related to line of sight communication.
In the ...
- 7,980
-2
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1
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190
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How to hide radio communications between airplanes? [closed]
I have 2 airplanes and I would like completely hide the communications between them.
There is a possible way that this communications would not be detected by our radio receivers around the world? ...
- 9
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1
answer
69
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What is the maximum electromagnetic bandwidth achievable between planets? [closed]
As an example, if communication was done using visible light, communication would be limited by the respective atmospheres, dust and obstacles along the line of sight. At the same time, multiple ...
- 3,236
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1
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105
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Noise spectral density for waveguide: I don't understand this calculation
In Introduction to Quantum Noise, Measurement and Amplification, on page 64 is computed the power spectral density of noise on a classical waveguide. I am really struggling to understand a step of the ...
- 1,450
1
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2
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67
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Wireless data transmission more than a bit at a time
I'm not that educated in wireless data transmission, but, the basics of frequency modulation and or amplitude modulation are quite basic. Is there any examples of transferring more than a bit at a ...
- 11
0
votes
0
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50
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Any method to detect extremely weak electromagnetic wave signal? (10^12Hz, level ~10^(-28) Watt per meter^2 per Hz)
Could you please let me know whether there is any method on the Earth to detect some EXTREMELY weak electromagnetic wave signal,
if it is a planar wave,
if its exact waveform is completely known (...
- 59
0
votes
2
answers
731
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Low frequency wave ability to penetrate object
as shown in this em wave spectrum image, the lower the frequency the better a wave ability to penetrate object.
https://c479107.ssl.cf2.rackcdn.com/files/20642/area14mp/pvgrynkw-1361853572.jpg
my ...
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