Sensor Array Project Guidance

I have a project that I am exploring best hardware and Attached is a picture of the sensor array I am wanting to set up. I have three rows of three sensors. A magnet will pass through each row. I want a setup that will determine which sensor the magnet is closest two as it passes through each row. Each row will light one of three LED’s based upon which sensor the magnet passed closest to.

I am trying to determine path through each row. Would Hall Effect Sensors or IR sensors be best for this or some other setup like a position sensor setup. I am trying to do this at lowest cost possible and it will be outside which is why I am leaning towards Hall Effect Sensors. Any input would be greatly appreciated.
!(http://Sensor Array.jpg)

Moderator edit: moved img tag.

Can you edit your post, and move all the text out of the image tag?

Hall sensors may work, though how accurate movement of magnet you want to tack? With current set-up it's about 30 15 degree.

Make sure you get linear hall affect sensors, not the cheaper hall switches which are a digital on/off instead of a ratiometric analog reading that will allow you to tell how far away it is also how fast is the magnet going to fly thru? And how close? You could induce noise in the wires going to the sensors causing improper reading

First off thanks for replies so far.

@Magician: My setup does not have to be extremely accurate. 15 to 30 degrees would be allowable.

@Winner10920: I already ordered the Hall Effect Sensors as you stated. They are not on/off switches they will supply a variable voltage depending on how close the magnet is. Also as to you second question. The magnet will come through at about 200 Miles Per Hour. The distance will be between 1 to 4 inches.

The magnet will come through at about 200 Miles Per Hour

200 x 1608 / 3600 = 89.33 m/s , nice speed, magnet will pass distance between two column in about 0.3 / 89.33 = 3.4 msec. What is the board? Even with mega it's close to the limit. One conversion 120 usec, array 9 x 120 = 1080 usec.

I was going to use Mega. If that will not work do you have any suggestions?

With mega , which has 16 analog inputs, should not be a problem. Have a link to hall sensors? Are they fast enough? Probably, calibration would be necessary, to make sure highest level of output is corresponds to closest one to a magnet. Other things, electrical induction in the wires.

Would shielding the wires suffice in protecting against induction in the wires?

That may help idk exactly I know the voltage induced is equal to the amount of lines of magnetic force times the length of the wire in the field times the velocity of magnetic change calculating the actual voltage your gonna get would require either alot of measuring or just a simple dry run past a wire id definetly keep the wires as short as possible, possible shield the longest/closest wires with some sort of iron to deflect the magnetic field around it, hopefully that wont throw off the reading tho id worry the most about damage to the hall effect sensor and anything connected to it from spikes