Resolving power of a radio telescope array: Quantum or classical?

In summary: With optical telescopes, the resolution is limited by the diffraction of light off the object. With radio telescopes, the resolution is limited by the temporal (coherent) resolution of the receiver.Yes. With optical telescopes, the resolution is limited by the diffraction of light off the object. With radio telescopes, the resolution is limited by the temporal (coherent) resolution of the receiver.
  • #1
Michael Price
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My question is: is the resolving power of an array of radio telescopes a quantum or a classical effect?
My question is: is the resolving power of an array of radio telescopes a quantum or a classical effect? The increase in resolving power of a single telescope, as aperture size increases, is easy to explain in terms of Heisenberg's uncertainty principle. But when we go an array of telescopes are told they "act together as one", but does that mean the signals from each telecope have to be coherently combined? Sometimes the signals are stored, prior to pooling, which suggests this is a classical effect.

One radio dish could process a single radio photon (in principle) to resolve its direction, but could an array of dishes resolve a single radio photon any more effectively?
 
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  • #2
Michael Price said:
But when we go an array of telescopes are told they "act together as one", but does that mean the signals from each telecope have to be coherently combined? Sometimes the signals are stored, prior to pooling, which suggests this is a classical effect.

Yes- Very Long Baseline Imaging (VLBI) imaging requires the signals be mutually coherent. Storing the digitized signals for later doesn't alter that- this is why the data requires extremely precise time-tagging in order to combine the digital data.

And yes- coherence is primarily a classical effect. There are quantum versions (the Hanbury Brown and Twiss effect is quantum), but VLBI uses plain ol' classical coherence.
 
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Andy Resnick said:
Yes- Very Long Baseline Imaging (VLBI) imaging requires the signals be mutually coherent. Storing the digitized signals for later doesn't alter that- this is why the data requires extremely precise time-tagging in order to combine the digital data.
Thanks. Does that mean the source must be varying for this to work? Or is the variation required so small that is never a problem?
 
  • #4
Michael Price said:
Thanks. Does that mean the source must be varying for this to work? Or is the variation required so small that is never a problem?

What source do you mean?
 
  • #5
Andy Resnick said:
What source do you mean?
I mean the source (star, galaxy,...) we are trying to resolve.
 
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Michael Price said:
Thanks. Does that mean the source must be varying for this to work? Or is the variation required so small that is never a problem?
No. It just means that the signals from the different antennas must be synchronized in time to an accuracy that allows for recombination coherently (i.e. a small fraction of a wavelength). This allows for interference effects from the phase of the waves observed in addition to the amplitude. So, when observations are recorded, they are "time stamped" with extreme accuracy.
 
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DaveE said:
No. It just means that the signals from the different antennas must be synchronized in time to an accuracy that allows for recombination coherently (i.e. a small fraction of a wavelength). This allows for interference effects from the phase of the waves observed in addition to the amplitude. So, when observations are recorded, they are "time stamped" with extreme accuracy.
Thanks. And that nicely explains why it is easier with radio telescopes than optical ones.
 
  • #8
Michael Price said:
I mean the source (star, galaxy,...) we are trying to resolve.

Yes.
 

FAQ: Resolving power of a radio telescope array: Quantum or classical?

1. What is the difference between quantum and classical resolution in a radio telescope array?

The resolution of a radio telescope array refers to its ability to distinguish between two closely spaced objects in the sky. Quantum resolution refers to the use of quantum mechanics to improve the resolution of the array, while classical resolution refers to the use of classical physics.

2. How does quantum resolution improve the performance of a radio telescope array?

Quantum resolution uses the principles of quantum entanglement and quantum superposition to improve the array's ability to detect faint signals and reduce the effects of noise. This allows for a higher resolution and more accurate measurements.

3. Is quantum resolution necessary for a radio telescope array to function effectively?

No, a radio telescope array can still function effectively using classical resolution methods. However, the use of quantum resolution can greatly enhance the array's performance and sensitivity, allowing for more precise observations.

4. Are there any drawbacks to using quantum resolution in a radio telescope array?

One potential drawback is the increased complexity and cost of implementing quantum technologies in the array. Additionally, the use of quantum resolution may require specialized training and expertise for scientists and engineers.

5. How does the resolution of a radio telescope array compare to other types of telescopes?

Radio telescope arrays typically have lower resolution compared to optical telescopes, which use light waves to observe objects in space. However, the use of quantum resolution can greatly improve the array's resolution and make it comparable to or even surpassing the resolution of optical telescopes.

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