Firstly let me express my thanks to all of those who have contributed to this project. The end product is much better than any single developer or manufacturer could be expected to achieve with resources justified by a "commercial" soaring product.
On 22/11/2011 23:06, Alexander Swagemakers wrote: > MC 0 = +11m above final glide > MC 0.1 = +8m > MC 0.2 = +3m > MC 0.3 – 0.6 = no glide bar > MC 0.7 = -596m (glide bar reappears) > MC 0.8 = -266m > MC 0.9 = -212m > MC 1 = -195m If you are on a marginal final glide into a head wind, your focus should be on the following (not necessarily in this order, and not exclusively): 1) Flying the glider (obviously). 2) Identifying outlanding options. 3) Estimating change of headwind component with altitude, particularly when descending below the "operating" altitude to an altitude band where the glide computer has no historical data. 3) Looking for sources of lift and/or sink. 4) Managing conflicting traffic heading to and already on the destination runway. 5) Evaluating the go home/land out decision. If you do find lift and stop to thermal, you should be very aware of the effects of wind drift. It will have a direct effect on (2), (3) and (5) of the above. You must maintain climb at a rate which more than compensates for the effect of your drift. The glide computer can help determine if you are achieving this see (c) below. A glide computer cannot be expected to do any of the above. However what it can do very accurately and quickly is: a) Navigate you directly to your target (via GPS). b) Provide an accurate data of your distance to go (via GPS). c) Calculate the hight required to reach your target based on glider polar (corrected for bugs and ballast), nominated "mcready" speed, nominated or estimated head wind profile. This is most conveniently displayed to the pilot as the "arrival hight" relative to ground (or a pre-nominated safety hight above ground). Note, that while the speed to fly to optimize distance covered in still air is best glide speed, and a "speed to fly director" should be set to "mcready" zero, the speed to fly to optimize distance covered towards an upwind goal is faster than best glide and the "mcready" setting on your speed to fly director will have to be increased to a positive value to provide the correct guidance to the pilot. The glide computer can also be expected to help determine the optimal "mcready" setting for maximizing distance covered towards the upwind goal. However if the glide computer starts presenting information like that quoted above, there is no way the pilot can be expected to assimilate it and make good decisions. The pilot can well be expected to ignore it and then distrust the GPS navigation data too. This would leave executing an outlanding as the natural consequence of good decision making. I would not like to see the above displayed to the pilot on a final glide into wind using the default settings of XCsoar. Use of wind drift while thermalling in calculation of things like the optimization of "assigned area" tasks is a different matter altogether. I see this as an interface problem not a theory one. Perhaps the most important requirement for a program like XSoar is to provide the right information at the right time, not too much and not too little. There is a high learning curve associated with glide computers particularly as the learning is typically done while airborne. Thus the default settings should be intuitive. Ian PS: I know of one very experienced pilot who claimed that the most important instrument in his brand new open class glider was the mechanical vario. He claimed he always could rely on it to tell him if the glider was going up or down, irrespective of which page was displayed on the glide computer, whether it had setup errors, software bugs, a battery failure or lost GPS signal ... ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Xcsoar-user mailing list Xcsoar-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xcsoar-user
