Estimate the number of pixels in an image

In summary, in order to include all LOFAR stations with a maximum baseline of 800 km at full resolution (defined as an angular resolution of 0.52 arcseconds), an estimate of the number of pixels needed to map the full primary beam would be needed. This can be calculated using the equation for angular resolution, which is equal to the wavelength divided by the baseline length. With a single LOFAR station operating at 150MHz and a physical size of 50m, the angular resolution is approximately 2.5 x 10^-6 radians. The relationship between angular resolution and image size is not clear, so further clarification is needed.
  • #1
Mazin Nasralla
13
0

Homework Statement


The physical size of a single LOFAR station, operating at 150MHz is about 50m. Estimate the number of pixels which would be needed to map the full primary beam if one wished to include all LOFAR stations (maximum baseline ~ 800 km) at full resolution.

Homework Equations


Angular Resolution = Wavelength / Baseline Length

The Attempt at a Solution



OK, so the resolution of the entire array is given by

Wavelength / Baseline Length which is 2m/800km = 2.5 x 10^-6 radians, or 0.52 arcseconds.

I don't how to relate this angular resolution to the image size which I think is a 50m square.

Can anyone help with this?

Thanks
 
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  • #2
What is the angular resolution of a single LOFAR station? I guess "primary beam" refers to that.
 
  • #3
Mazin Nasralla said:
... at full resolution.
Define "full resolution"
 

1. How do you estimate the number of pixels in an image?

To estimate the number of pixels in an image, you can use the formula: width x height = number of pixels. This formula works for both rectangular and square images.

2. Can you estimate the number of pixels in a non-rectangular image?

Yes, you can still estimate the number of pixels in a non-rectangular image using the same formula of width x height = number of pixels. However, the resulting number may not be exact since non-rectangular images often have varying levels of resolution.

3. How accurate is the estimation of pixels in an image?

The accuracy of the estimation of pixels in an image depends on the resolution and quality of the image. Higher resolution images with more pixels will have a more accurate estimation compared to lower resolution images.

4. Is there a more precise way to estimate the number of pixels in an image?

Yes, you can use image editing software or online tools that have the ability to display the number of pixels in an image. This method will provide a more precise estimation of the number of pixels in an image.

5. Why is it important to estimate the number of pixels in an image?

Estimating the number of pixels in an image is important for various reasons. It can help determine the resolution and quality of an image, which is crucial for printing or displaying the image on different devices. It can also help with file size management and optimizing images for web use.

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