I Holography used in telecommunications

AI Thread Summary
Holography has potential applications in telecommunications, particularly in the accurate mapping of parabolic reflector dishes using off-axis microwave signals. Historical methods involved testing microwave links by analyzing the variations in received power as antennas were raised, which created a holographic representation of the signal path. This setup demonstrated that the interference patterns from direct and reflected signals could form a hologram, capturing phase information. Modern technology could analyze this data more effectively, potentially revealing the locations of ground-reflected signals. The discussion highlights the importance of phase reference in creating holograms for telecommunications applications.
ElectroFractal
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I am curious to know if holography is used in telecommunications or if there is research on this topic.
Hi PF!

I am interested to know whether there are applications of holography in telecommunications, and if there is research on this topic. If there is some literature on this topic (provided holography is used in computer networking) where I can read and learn more in-depth about this topic, I will appreciate it very much

Thanks in advance!
 
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In the 1970s we used to occasionally test microwave links by raising an antenna up the mast from ground level. The received power varied in a rippling manner as height was increased, depending on the path. The cause of this ripple is that the direct signal (which may be considered the reference) combines with a delayed ground reflected signal and the two combine as phasors. I realized that this set up is creating a hologram, as with light. The ripple is a holographic image of the path. However, was never able to try and read-back the final plot in some sort of holographic way, such as with a laser, so never tested it. I suppose today a computer could analyse the information directly. I imagine the result would just be the location of any ground reflected images.
 
tech99 said:
I realized that this set up is creating a hologram, as with light.
Amplitude alone is insufficient. By using a separate fixed antenna as a phase reference, then recording the amplitude and the phase as you raise the antenna, you will have a hologram.
 
My understanding was that the hologram captures the phase information within the interference pattern, so that a separate phase measurement is not required.
 
You need a phase reference. In an optical system you use two different paths for the light, the light reflected from an object and another beam coherent with the first but taking a different path to the recording medium thus acting as a phase reference.
 
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