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Diffstat (limited to '4.-Antenna-Array-Setup.md')
| -rw-r--r-- | 4.-Antenna-Array-Setup.md | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/4.-Antenna-Array-Setup.md b/4.-Antenna-Array-Setup.md index 2bb00a9..f520a04 100644 --- a/4.-Antenna-Array-Setup.md +++ b/4.-Antenna-Array-Setup.md @@ -48,7 +48,7 @@ For both templates print the center pentagon and five arms separately, then glue If you wish to determine radio sources from 360 degrees around the array, then the antennas should be arranged in a uniform circular array (UCA). The interelement spacing (the distance between the tip of each neighboring antenna element in the array) needs to be set specifically for a range of interested frequencies. You must design your array such that the interelement spacing `I_e` is less than half a wavelength `λ` of your highest frequency of interest -`I_e=sλ` +`I_e = sλ` where `s` is the wavelength spacing multiplier that must be <= 0.5 and `λ` is the wavelength in meters. @@ -121,7 +121,7 @@ Obviously if you are running the antennas on a vehicle, you do not want the ante # Theory of Resolving Resolution If the resolving resolution is 10 degrees, we can say that the actual bearing is somewhere within a 10-degree arc. -Here we briefly explain the background theory behind what sort of accuracy resolution we can expect from a 5-element array system. With a 5-element circular array spaced at 0.5 λ, we might roughly expect a resolution of about 8 degrees. With a 5-element linear array we could roughly expect about 3.4 degrees. This is the best-case resolution, not considering external distortions like multipath. (This may appear inaccurate, but in practice when multiple readings are taken from many locations the inaccuracies simply average out and become negligible.) +Here we briefly explain the background theory behind what sort of accuracy resolution we can expect from a 5-element array system. With a 5-element circular array spaced at `0.5λ`, we might roughly expect a resolution of about 8 degrees. With a 5-element linear array we could roughly expect about 3.4 degrees. This is the best-case resolution, not considering external distortions like multipath. (This may appear inaccurate, but in practice when multiple readings are taken from many locations the inaccuracies simply average out and become negligible.) To estimate the error, we used the Rayleigh resolution calculation from wave physics. The Rayleigh formula states that resolving resolution is given by `θ=1.22λ/D`, where `D` is the aperture of the antenna array. For a circular array the aperture is equivalent to the diameter, and for a linear array it’s equal to the total length. For a linear array however, it must be taken into account that the effective aperture will appear to be much smaller when seen from the sides. |