A good explanation from DK3WN on how to determine what TLE data belongs to what Satellite.

Based on the latest cubesat TLEs we have now three groups of objects (B+C+D, E, F+G). The first group are the 1U cubesats – they are only a few km apart. In 13 sec distance is RAX-2. I think F and G are the DICE sats.

Elena-III All TLE 02-11-2011

A simple way to determine the TLE, Take one beacon frequency – in this case 437.435 MHz (belongs to RAX-2). Then I calculated all the doppler frequencies for all objectes on a high 66 deg elevation pass. If the doppler = 0 then we have TCA. In this way you can calculate the distance between the TCA of each satellite.

Elena-III All TLE Doppler correction

You can see the 13 sec difference of RAX to to the first group (E1P, MCubed and AubieSat-1)

RAX-2 Zero 02112010 11:13UTC Pass

Take a look at the spectrogram – the horizontal yellow line is the center frequency of 437.345 MHz and the vertical one is the calculated time for RAX-2. And as chance would have it – we have a packet there. If you take the middle frequency of this 9k6 packet -> it all comes to one point.

Source: Satblog – DK3WN