Event Types¶
From the track analysis point of view, a task is defined by a set of controls (turn points, gates or legs). The task is analysed against each control and different event types are detected.
There are other events which are independent from the task design. They can be obtained by analysing the track itself (track events).
Finally, some events are generated by the logging devices or by the pilot operating them (IGC events).
Turn point events¶
A turn point is a point defined by its coordinates on the surface of the Earth where competitors are supposed to cross. A radius is defined, creating a circle around its central coordinates, or a cylinder that extends upwards to an unlimited altitude.
The radius is conceived as a margin that must cover the sum of errors introduced by:- The GNSS device used by the task designer to obtain the coordinates of the point.
- The ability of the task designer to physically visit the point.
- The GNSS system used by the competitor while flying the task.
- The ability of the pilot to fly above the point.
When a track is analysed against a turn point the following events can be detected.
| Event | Meaning |
|---|---|
| Enter cylinder | The track enters the cylinder that defines a turn point |
| Turn point crossed | The track crosses the turn point's cylinder |
| Exit cylinder | The track exits the cylinder that defines a turn point |
| Nearest (missed) | The track reaches the minimum distance to the turn point without crossing the cylinder. |
| Maximum distance | The track reaches the maximum distance to the turn point. |
Gate events¶
A gate is a segment between two points on the earth. It is centered on the ideal path that has to be flown by the pilot. The concept of radius is also used as the maximum deviation from the ideal path to either side. Therefore the gate width is twice the gate radius.
Gates are displayed as segments with a coloured dot at each end. The colours are the same as the ones used for navigation: red for the left side and green for right side. The image example shows a gate that has to be crossed in NW direction (310º).
The following events may be detected by analysing a track against a gate:
| Event | Meaning |
|---|---|
| Gate crossed | The track crosses the gate in the proper direction |
| Inverse crossing | The track crosses the gate in opposite direction |
| Nearest (missed) | The track reaches the minimum distance to the gate without crossing it. |
| Maximum distance | The track reaches the maximum distance to a the gate. |
Leg events¶
A leg is a line defined from a turn point to another turn point. A radius is defined, establishing left and right margins, creating a rectangle around the line with the shape of a corridor.
Legs are displayed using a line that approximates the ideal path to be flown by competitors. The image represents a leg from turn point 67 to turn point 54. Some gates can be seen along the leg.
The following events can be detected along a leg:
| Event | Meaning |
|---|---|
| Leg start | After crossing a turn point the track starts following the leg. |
| Leg end | The track enters the end turn point's cilynder coming from the leg's area. |
| Enter leg area | The track enters the leg area from one side, not from a turn point. |
| Exit leg area | The track exists the leg area on one side, not at the ending turn point. |
| Backtracking | A track segment inside the leg area goes backwards with relation to the leg direction. |
Track events¶
Regardless of how the task is designed, multiple events can be detected along a track which are independent of any task design: speed, acceleration, signal loss or recovery, loops, take-off or landing.
| Event | Meaning |
|---|---|
| Track lost | The track logger stopped producing track points, possibly due to satellite signal loss. |
| Track recovered | The track logger resumed producing track points, possibly after the recovery of the satellite signal. |
| Intersection ahead | A loop has been detected, two track segments intersect with each other within a certain time. This event is associated to the start of the loop: the oldest track point of the oldest of the two intersecting segments. |
| Intersection | Same as above, but this event is associated to the end of the loop: the oldest track point of the newest of the two intersecting segments. |
| Maximum speed | This event is associated to the track point where the highest speed is detected. |
| High acceleration | An acceleration that can't be achieved by a light aircraft was detected. This is a symptom of bad track quality and other spurious events can be detected. |
| Take off | Take off was detected |
| Landing | Landing at an expected landing zone was detected. |
| Outlanding | Landing was detected far from an expected landing zone. |
IGC events¶
The IGC file format registers a number of events detected by different logging devices. If the track log contains any of those events they are displayed as IGC events.
| Event | ||
|---|---|---|
| Altimeter Pressure Set | Engine On | On Task |
| Camera Connect | Engine Up | Pilot Event |
| Camera Disconnect | Finish | Photo Taken |
| Change of Geodetic Datum | GNSS Connect | Start event |
| Engine Down | GNSS Disconnect | Turn Point Confirmation |
| Engine Off | Low Voltage | Unknown IGC event |
Only the ones marked in bold are normally seen in Microlight and Paramotor competitions.