Out and Back Distance Record / Data, Discussion and Proposal

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Out and Back Distance Record / Data, Discussion and Proposal

Postby sd » Mon Mar 29, 2021 1:10 am

3/2021

On 3/31/2021 this topic was updated from its initial posting on 3/29/2021 to clarify, add flights for Jeff and Willy, plus update the KMZs for Carter and Marty to add time data and attempt to standardize the format somewhat.

Data

Group Web Animation with flight dates changed to sync in Ayvri
https://ayvri.com/scene/g0jg73pnjo/ckmxys04t0001256li6lgoi2u

KMZs Attached for reference:
Carter Crowe 3/28/2021 flight to Topa Bluffs and Back
    FAI Rules / 32.5 mile legs x2 = 65.0 miles over 5.94 Hr ~ 10.9 mph
    SB Rules / 32.7 mile legs x2 = 65.4 miles over 6.73 Hr ~ 9.7 mph
Marty Devietti6/10/2020 flight to Topa Bluffs and Back
    FAI Rules / 31.4 mile legs x2 = 62.8 miles over 4.77 Hr ~ 13.2 mph
    SB Rules / 32.5 mile legs x2 = 65 miles over 5.34 Hr ~ 12.2 mph
Willy Dydo 3/16/2021 flight to Boyd’s and Back
    FAI Rules / 30.8 mile legs x2 = 61.6 miles over 4.94 Hr ~ 12.5 mph
    SB Rules / 31.7 mile legs x 2 = 63.4 miles over 5.13 Hr ~ 12.1 mph
Jeff Longcor 2/21/2021 flight to Topa Bluffs and Back
    FAI Rules / 29.5 mile legs x2 = 59 miles over 4.25 Hr ~ 13.9 mph
    SB Rules / 30.4 mile legs x2 = 60.8 miles over 4.84 Hr ~ 12.6 mph
Carter Crowe 6/10/2020 flight to Topa Bluffs and Back
    FAI Rules / 29.4 miles legs x2 = 58.8 miles over 4.29 Hr ~ 13.7 mph
    SB Rules / no score advantage using SB rules
We are also aware that Scott Angle had a HG flight to somewhere in Ojai and back that may qualify for 1st place? We don’t currently have documentation about Scotty’s flight, but we are in the process of discovery.


Note that parallax is an issue when measuring in Google Earth. One method of avoiding parallax measurement errors is to flatten the terrain (uncheck the terrain box located at the bottom of the layers tree) and reference placemark altitudes to ground rather than absolute altitude (in various item properties).

Discussion
I’ve done some research on Out and Back records.
I was previously under what I think was an incorrect perception that XContest had a category for Out and Back. XContest does calculate more points in their scoring method for various triangles, but I don’t see a category for Out and Back? The XContest triangle scoring is a bit complicated and appears to offer different bonus multipliers for various degrees of alignment with the FAI triangle requirements.

One of the philosophical concepts of the XContest rules is that you don’t need to declare your intent prior to the flight. You can do the flight and their algorithm will calculate a score based on your GPS track file. This simplifies the admin overhead and the documentation simplicity increases participation.

The international sanctioning organization for various sport aviation records is the
FAI / Fédération Aéronautique Internationale
https://www.fai.org
Various FAI “Commissions” sanction competitions (HGs and PGs are part of the CIVL Commission) and they also sanction “Records and Badges”. For an “official” record to be accepted by the FAI, you need to complete at least some pre-flight requirements like obtaining a Sporting License.

Hang Gliding and Paragliding Record requirements are specified in the
FAI Sporting Code Section 7D - Class O Records and Badges
2020 Edition Effective 1st May 2020
sporting_code_s7_d_-_records_and_badges_2020.pdf
FAI rules for Record Flights
(623.02 KiB) Downloaded 5 times

Note that Paragliders are listed as Class 3 Hang Gliders

Flights can be either “Declared” or “Free”. In the “Declared” category, location points are declared prior to the flight, but in the “Free” category location points may be declared post flight. There is a distinction between “Turnpoints” [section 1.5.8] and “Checkpoints” (1.5.11). where Turnpoints are declared prior to the start and Checkpoints are optional and can be identified post (after) the flight competition. For simplicity, when referring to a Free Checkpoint, I will use the term Turnpoint. Section 1.5.5.8 list the record categories for “Free” flights including “Free Out and Return Distance”.

Section 1.5.5.8 and 3.2.1 also list other “Free” categories like flights around multiple checkpoints (up to 3 turnpoints in addition to the start and end points) and triangles. You can apply for any of the records you choose, but in the discussion below I will focus on the Free Out and Return Distance Record.

Various points (start points, check points etc.) are coordinates surrounded by a cylinder.400 meters in radius, or 800 meters in diameter.
There is discussion and illustration in the documentation about measuring to the edge of the cylinder, not the center (5.2.5)
For “Free” or undeclared Out and Return, we can declare the “points” after the flight, so for the downrange turnpoint we can simply use the actual turnpoint cordinates and ignore the cylinder because we could adjust the cylinder after the fact to match the same scoring result as if we simply use the turnpoint.
For the Start/Finish cylinder, we do need to measure to the edge of the cylinder so there may be some geometric penalty that increases as the distance between the actual start and end points increases.

I think we also want to consider the arbitrary FAI cylinder radius of 400 meters and our local objectives. Locally, we are trying to get out and back, so we are striving to define what “back” means. Locally, that often means getting back to Parma or East Beach? We could follow the FAI 400-meter radius requirements, but that complicates the flight. As start/finish cylinder size increase the geometry will also result in an increasing penalty.

I would argue that a 400-meter radius doesn’t reflect what we often do in SB, which often entails getting on course up higher and returning lower? We could permit a cylinder of a larger size (up to 4 KM radius ~ 2.5 miles), but as your cylinder gets bigger you will also have a larger penalty because geometrically we are measuring from the edge of the cylinder and not the center. I suggest limiting the max cylinder radius to 4000 Meters because that is half the distance from the ridgeline to East Beach. We need to have some limit on the cylinder size or an open distance flight could be scored as an out and return at half the leg distance x2 legs so the total would equal the straight line open distance. Out and Return flights can be more difficult than open distance (but not always) because open distance can sometimes have a tailwind advantage, however, if a course is obstacle limited (like east wind in the Santa Clara River?), then an out and return might have a local advantage over open distance and be able to score more miles.

One might argue that if you get back over Casitas Pass and out to Bates then you did an out and return, but the geometric penalty would subtract the diameter of a 10 mile radius circle from the total score so it wouldn’t be competitive anyway. We could use a max cylinder size that connects the Painted Cave Windmill to East Beach, but that would require about an 8 KM cylinder and would only yield a scoring advantage of less than 400 meters compared to using a smaller 4K meter cylinder limit. 4K is also intuitively comparable to 400 so it seems like a natural choice for Santa Barbara’s scenario that will yield a penalty of up to about 2.5 miles (x2) compared to flights that terminate on point.

To permit larger cylinders (larger than 400 meters) up to 4 KM we should add one minor requirement for the cylinders greater than 400 meters. The center of the cylinder must bisect a line (the diameter line of the cylinder) that touches both the outbound and inbound ground tracks, otherwise everyone would use the max cylinder size and place it back to minimize the geometric penalty.

If we go the trouble of scoring a flight to the edge of a start/finish cylinder, it’s not that much more effort to score it both ways yielding one score based on the FAI rules requiring a 400 meter start cylinder and 2nd local score using a larger cylinder size (up to 4 KM radius) that will maximize the score.

The FAI measures accuracy to 1/100 but I think that degree of accuracy is cumbersome, I recommend we round our measurements to a tenth of a mile. An exception to this would be in drawing the cylinders where we strive to be within about a meter or 2 of the actual cylinder size to achieve an accuracy within a few meters. For cylinder size it is easier to work in meters than miles for resolution accuracy. In calculating a score there might be some trial and error in determining the actual cylinder placement to achieve the maximum score.

The FAI documentation also addresses subtraction for Altitude Loss, but the calculations yield results that are not relevant to our local Out and Return scenario as per 3.4.3

The FAI also requires that new records must break the old record by 1 KM (3.2.4.1). Since we mostly work in miles locally, I think we should require 1 mile rather than 1 KM? I suggest that a pilot can claim they “tied” the old record, but to claim a new outright record a pilot should exceed the old record by something like 1 mile, or if they exceed the prior distance by less than one mile than perhaps they could claim an outright record if their new flight was faster than the prior record flight by at least 1 mph average speed?

The FAI requires an applicant to submit various documentation items to support their record claim. I propose that a pilot claiming a local out and back record post a reasonably descriptive narrative of their flight. To have a record we need to actually create a record we can reference. We all know that Scotty flew from SB to somewhere in Ojai and back, but we don’t have the details archived for comparison.

Proposal:
I propose that we (the SBSA) adopt the FAI methodology for calculating “Free” Out and Return flight distances without the requirement for a Sporting License and permit a larger size start/finish cylinder up to 4 KM in radius.

For clarification, I am proposing that:
Anyone can claim a Santa Barbara Free Out and Return Distance Record without prior declaration or organization membership requirements.
The Start/Finish cylinder must be located somewhere along the front range between Gaviola and White Ledge Peak. (other sites like Ojai, Pine, or Fillmore could have their own local records).
For the downrange turnpoint, use the actual turnpoint coordinates as the sole turnpoint without regard to a cylinder.
For the FAI compatible score, we use the FAI “rules” which permit adjusting a 400-meter Start/Finish cylinder to fit the track and then measure from the edge of the cylinder to the turnpoint along a line that is colinear with a course line drawn from the turnpoint to the cylinder center.
For the local Santa Barbara “Rules”, we permit a Start/Finish cylinder of up to 4 KM in radius, but the center of the cylinder must bisect a line (the diameter line of the cylinder) that touches both the outbound and inbound ground tracks.

Altitude loss allowed is not relevant to our local scenario.
We round the leg distances to the nearest 1/10th of a mile and add the leg distances to get the final score.
A new record should exceed the prior record by at least 1 mile or exceed the prior record by less than a mile and record an average speed that is at least 1 mph faster than the prior record speed.

The pilot claiming a local record must post a reasonably descriptive narrative of their flight and their IGC file.

Additional Discussion

I don’t have any authority to make “rules”. I am not suggesting that we can’t individually make up our own objectives, but the closed course flight scoring is more complicated compared to simpler open course scoring. I think there is merit to Carter rules that indicate you need to land within “x” distance of launch? Also, the FAI has categories for other flights like distance around multiple turnpoints and closed triangles.

Some pilots think we should simplify by some criteria like if you back to Parma it counts, but there are countless variations that might be left out so some method of assigning a number (mile) score to flights offers more inclusive objectivity? Personally, I rarely land a Parma and prefer to land near the bus stops along the coast.

Google Earth’s drawing and measurement tools are somewhat limited. There are likely other programs out there that might yield faster and more accurate results, but the Desktop version of Google Earth is free and utilized my most pilots.
________________________________
Google Earth Measurement Method
For my own reference the methods I use to create the geometry in Google Earth are:

When creating geometry like circles I untick the “terrain” checkbox in the layer tree to flatten the terrain, otherwise the circles and ground track lines are distorted.

For points, I use altitude references to both ground and absolute altitude depending on the use. Sometimes I need both. For differentiation, I use white color for measurement points referenced to absolute altitude, and green color for measurement points referenced to ground. For the Out and Back downrange turnpoint I make 2 placemarks. One with absolute altitude and one referenced to ground.

For lines, I use the measure tool. You could also use the “path tool”, but using the line option in the measure tool also creates a path with the added ability to see the distance as you drag or click on a previously created point to zoom to it.

The FAI 400 Meter radius circle is a bit different than the larger size cylinder because the outgoing and incoming tracks don’t need to intersect the circle diameter when adhering to the 400 meter cylinder, so I’ll simply do some trial and error drawing out 400-meter circles to fit the tracks in a way that maximizes the leg lengths. I first put down a placemark to mark the center for reference.

Once the circles are created, I’ll draw a course line from the turnpoint to the center of the circle (or circles). Save this path but will delete later. Then place a reference point where line intersects the circle circumference, then create a path from that point to the circle center (color it white) and another line from the circumference point to the turnpoint, then delete the course line to leave the 2 colinear lines. The total out and back flight distance is the leg distance x2.

Diameter Cylinders: I’ll create a 2-point path (straight line) with the measure tool such that the two end points touch the ground tracks. Save the path. Then calculate half the length and create a circle with the measure tool using one end of the path as the circle center and drag out the circle radius to equal ½ of the diameter length of the previously created straight-line path. You can zoom in for resolution accuracy. You need to save the circle but will delete it later, so accept the default name. The newly created circle will bisect the previously created line segment (path) in half. The intersection point is then used as the center of the cylinder circle of the same radius. I’ll then delete the 1st construction circle but first I put down a placemark at the 2nd circle center so I can reference the center.
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