AeroPod, PowerPod and Newton

So I FINALLY got my Isport up and running this weekend after having to replace the wheel sensor initially (thanks to the ibike folks to taking care of me so fast). The cal ride and coast down went by without a hitch so I was happy about that. Although I'm certainly not a physicist, the mechanics sorta make sense to me. What I don't understand though is how the isport measures power from a standing start. Starting off from a stop light into a mild sprint, I would see the power meter jump to a high reading, then level and drop off as I slowed down. How does it measure this without any appreciable wind resistance? On the flip side, descending a hill approaching 25 - 30 mph my power would be really low. How does it differentiate between the two? Thanks for taking the time to read this, I'm just really amazed at the technology that went into this thing.

It has an accelerometer so it can measure the acceleration of your mass from a standing start. The accelerometer also measures slope so on the descent it factors in the downhill "help" you're getting.

Are you saying the accelerometer measures how many watts based on the force of takeoff? I thought the iBike did the normal calculations of change in velocity, Tilt, weight, etc. I thought all watts displayed were the result of calculations, not based on a sensor. Are you sure about your reply?

I don't think nigeld is saying the accelerometer is doing the measuring; it's contributing to the equation. However, the accelerometer should contribute the most influencing information when accelerting hard from a stop. As you accelerate the amount of energy expended is tremendous (it's all relative) compared to most other factors such as wind, drag, rolling resistance, etc. Same as a car, all that horsepower is used to accelerate, once you're up to speed it doesn't take much to maintain until the the other factors start kicking in.

Try accelerating hard from a stop in a headwind. Sure it's tougher but the majority of the effort is due to the hard acceleration.

I was just pointing out the most relevant sensor as chrisf was only considering wind speed. Presumably, as racerfern says, all data would be factored in, but under normal conditions the acceleration would be the most relevant factor from a standing start, as the change in velocity is the greatest, you're going from zero to whatever.