Arduino as Frequency Sensor with output to Pi for Signal Processing.

Hi,

I have a circuit with a varying (analogue - essentially pure cos/sin + noise) frequency output (the frequency varies when I move an antenna, so we can't predict when the variations will happen). What I want to do is to find some way to calculate the frequency output (as a function of time), do some signal processing [I figure this needs to be done on something like a Raspberry Pi as the arudino might not cope? I'm hoping to be able to use Python & SciPy)] and then plot a 2D color map of the frequency against the position of the antenna.

[Obviously need to also figure out some way of sensing where the antenna is! (on a 2D plot) This part I'm not very sure about at all...]

Question is - can I do most/all of this with an Arduino? One thing I wonder if I could do is to restrict the input frequency range into the audio and then use some of the audio projects people have here?

Any help at all would be much appreciated Thanks! :)