RZS10 wrote: ↑16 Jul 2017, 14:00
1) would be the car arriving in it's grid box (signal strength going from 0 to what i initially called 'zero distance'
2) car standing still in on the grid, since it is not moving there is no change in signal strength
3) car starts moving
4) car is exactly above the loop
then the signal goes back down to 0
I had originally made a lengthy post in response to this but it didn't get saved...so here's a shorter version (if that's possible!)-
Curious: Does a mobile phone signal bar meter go to zero when you are standing next to a cell?
Unless I am missing your point,
No, the Signal Strength does
not return to zero as long as the Tx is in proximity. In addition, as mentioned, the tolerance of the loop allows for anomalies that would include timestamps for signal
higher or lower without movement, making any
measurement of it's location in proximity in relation to the loop invalid. (For the sake of accuracy, 'tis why I specifically included anomalies in my representation by reference to actual X2 Admin data...additionally, there are many reasons for this due to magnetic induction limitations, reflection and power strength of the loop at a given section of the track).
Edit: [Trying to understand your point: Are you referring to the signal drop after the competitor has left its box? If so, then yes, at some point the signal strength would decline, but if we are talking milliseconds, there's too much noise in the system to reliably determine where the car was and what wasn't in relation to the loop. Exercise: consider the parallax of the cone of the Tx to the loop at height in relationship to its movement over time in milliseconds. Also include reflection, interference and power fluctuation. The meter graph you are imagining isn't that accurate, and includes at times vertical time stamps since the Tx at times emits more signal per second than the decoder registers..loops pick up as much as 1400/hits/sec and as low as 6/hits/sec.] Remember, by design the loop is 24" wide...
so the car could travel as much as 24 inches at max peak without signal declination!
Ultimately the designed purpose of the Tx is to transmit it's unique data signal constantly, and the purpose of the loop is to receive this unique signal...
any signal from this Tx,
any signal....
even just one hit (regardless of strength or proximity, is enough to validate the Tx was on, over or near the loop, thus allowing for a scored passing. If the car is near the loop, it will pick up signal...(think geiger counter).
Something to think about - Tracks with Pit lane loops in close proximity to the actual track loops
have, do and will on occasion pick up a stray Tx signal from cars traveling on the opposite surface. Given this, if one were
using only the equipment to certify a cars position, the timekeeper would have to conclude that the car was in both places at the same time. (Cool!)
[Edit:
This would mean a short start box loop would also pick up the car next to, ahead or behind it if the sensitivity was such to detect minute movement]
So sadly, no matter how we analyze Signal Strength, or transmission location versus loop location, based on its design parameters, you
can't reliably use or establish a
consistent protocol to detect quick inch by inch movement using the
current FIA
Tx and loop system. We must consider what the equipment is designed to do, include it's limitations, and conclude if it is capable of reliably performing the task. In this case, this is not the system used for such determinations.
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