Phase Unwrapping with ATAN

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stiltz

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Hi,

We know that if we use four quadrant arctangent function i.e. ATAN2(Q,I) where we have wrapped phase with discontinuities of 2*PI. There are algorithms which can unwrap this phase. But there are some situations where we have to use two quadrant arctangent function i.e. ATAN(Q/I) where we have wrapped phase with discontinuities of PI. I can not find any algorithm to unwrap this phase. Can any one help me how to unwrap the phase in this case ????

Thanks,
 

Hi stiltz,

you can construct you own atan2(Q,I) function using standard atan2(r) function.
If I'm not wrong:

(Attention to the cases I==0 !!!)

if I>=0
atan2 = atan(Q/I)
else if y>=0
atan2 = atan(Q/I) + pi
else
atan2 = atan(Q/I) - pi
end

then, you can unwrap like you know.
Regards

Z
 

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