Using SeeYou for Soaring Flight Analysis GPS-trace based flight analysis

Real Question: How I do become a better cross-country glider pilot

Agenda Overview SeeYou capabilities Quick review of theoretical underpinnings of X-country flight optimization Example of competitive analysis of G-Cup flights on May 19 th, 2003

Overview SeeYou Capabilities Turnpoint Database Management –Importing/creating new turnpoints –Modifying/deleting turnpoints Task Database Management –Importing tasks/creating new tasks –Modifying/deleting tasks GPS Trace Analysis –Importing GPS traces (connection wizzard) –Analyzing flights 2-D flight analysis –Single flight –Multiple flights –Synchronization –Customizing screen 3-D flight analysis –Single flight –Multiple flight –How to move about Barograph-type analysis of flight parameters –Cross-matching of parameters Statistical Analysis –Info Available –Selections

Quick review of theoretical underpinnings of X-country flight optimization –MacCready (deterministic) –Mathar (stochastic) –Cochrane (stochastic)

MacCready Theory Q: How fast should I fly based on known lift conditions ahead of me in order to minimize time from A to B when my altitude is unlimited? Answer: Classic speed-to-fly (MacCready) theory – provides explicit interthermal cruise speed and implicit rule, in which thermals to climb A B Distance s Net lift l v cruise polar sink v target polar sink ps at v target Net lift l in next thermal +/-inthermal airmass sink/lift Cruise time to next thermal Time spent regaining altitude in thermal Two key constraints of MacCready theory: Deterministic model, based on known net lift l – which in reality is unknown Doesn’t account for limited altitude

Constraint 1: Uncertain lift – R. Mathar, Technical Soaring Oct 1996 Q: How fast should I fly based on unknown lift conditions ahead of me in order to minimize time from A to B? Answer: If there is a distribution of expected lift set the MacCready ring (or equivalent device) to the harmonic mean rather than the arithmetic mean (=straight average) Mathematics: Practice: Key insight Provides theoretical underpinning for common sense strategy to fly a little more on the cautious side based on uncertainty

Constraint 2: Limited Altitude – R. Mathar, 1996 Q: What is the best strategy in order to minimize time from A to B given variable known lift conditions and limited altitude? Answer: Depends on glider performance and the altitude available. With limited glider performance and/or limited altitude the weakest lift needed to get around the task is dominant in determining optimum speed-to-fly Example: Key insight Provides theoretical underpinning for common sense strategy to fly a little more on the cautious side with limited altitude A B Ground 2 knots6 knots2 knots

Combining the Constraints – J. Cochrane, 1999 Q: What is the best strategy in order to minimize time from A to B given uncertain lift conditions and limited altitude? Answer: No closed form solution. Numerical investigation yields insights: Confirmation of standard McCready theory: Set McCready ring (Speed-to-fly computer) Fly best speed when lift below setting Circle, if above setting Additional insights relative to McCready theory: Lower the setting as you get lower Increase setting with altitude Use setting well below best climb of day Start final glides low & aggressive, end conservative Deficiencies: Thermals assumed static (daytime & height variability) Information driven discrete strategies (clouds, topography) Competitive dynamics (game theory, scoring asymmetries) Wind, ballast options etc. Key insight: Common sense is confirmed; implementation requires a statistical mindset when flying; real life too complicated for theory

Example of competitive analysis of G-Cup flights on May 19 th, 2003

A beautiful day…the weather on May 19 th, completions to analyze1K2, B21 (2 flights), DRT, FD2, PX, SM, TB, TUP

Early bird, doesn’t catch the worm… …but potentially gets to complete the G-Cup twice in a day! The Pros leave at ~1:30 pm… …with a few newcomers painting thermals on course for them

Rush, ΔΣ (=Delta Echo)! High Interthermal speed is not sufficient for success… …but beginners might take heart and lower that nose…

MacCready alright… Too much of a good thing…is a bad thing… …especially when easy does it!

...but in modesty lies wisdom indeed!

Time well spent…? Circling for lift is so 20 th century…

Scaling new heights Low energy consumption is the name of the game, even when energy is free

Summary of Relevant statistics

Summary of Relevant statistics 2