I am trying to turn the 3.5e SRD's degrees-of-turn-per-feet-of-game-movement numbers (such as 45 degrees of turn per 5' of movement with 45 degrees of maximum turn per square for a creature classed with poor flight maneuverability) into an actual minimum possible turn radius for a flying creature; however, I cannot figure out from the SRD text on the topic whether this figure is supposed to be interpreted as 45 degrees of turn between two points 5 feet apart, 45 degrees of turn over 5' of along-track movement by the creature, or flying 5' and then turning 45 degrees about a point.
Apparently, all the SRD has to say about the figures in question in the table is:
Turn
How much the creature can turn after covering the stated distance.
Maximum Turn
How much the creature can turn in any one space.
The DMG says the same, and the PHB doesn't have anything more to add. Where can I find more detailed information about how flight maneuverability works on the grid?