Telemetry CSV Format

This document describes the internal file format used to store laps. Files are stored at %LocalAppData%\ApexLab\Sessions\*.csv.

Note

This is not a user-facing import format. The app populates the catalog exclusively via live capture (LMU, etc.).

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Separator

Comma , or semicolon ;, auto-detected from the header line.

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Minimum Header Row

Required columns (case-insensitive):

Time,Distance,Speed,Throttle,Brake,Steering,Gear,X,Y,Lap

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Full Export Header

Written by CsvTelemetryWriter:

Time,Distance,Speed,Throttle,Brake,Steering,Gear,X,Y,Lap,OfficialLapTime,NumPenalties,NumPitstops,InPits

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Comment Metadata Lines

Optional lines before the column header:

# Track: Spa-Francorchamps
# TrackLayout: Full
# Vehicle: Ferrari 499P
# Recorded: 2026-04-19T20:00:00Z
# Source: ApexLab 1.0
# GameSource: LmuRf2
# WeatherAmbientC: 18.5
# WeatherTrackC: 32.1
# SetupTc: 4
# SetupAbs: 3
# SetupBb: 55.0
# SetupMap: 5

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Data Columns

Column	Type	Required	Description
Time	float (s)	Yes	Seconds since lap start — used for lap time derivation and cumulative delta
Distance	float (m)	Yes	Primary axis for lap comparison — stable across laps unlike time
Speed	float (km/h)	Yes	Core performance metric
Throttle	float (0–1)	Yes	Driver input — power application
Brake	float (0–1)	Yes	Driver input — deceleration
Steering	float (°)	Yes	Identifies corners vs. straights in TrackSegmentation
Gear	int	Yes	Vehicle context
X, Y	float	Yes	World-space position — track map rendering, centerline fusion
Lap	int	Yes	Lap boundary detection — change in value = new lap
OfficialLapTime	float (s)	Optional	Best-quality lap time source from the game engine
NumPenalties	int	Optional	Cumulative penalty count
NumPitstops	int	Optional	Cumulative pit stop count
InPits	int (0/1)	Optional	1 = vehicle in pits at lap end → CountsForSessionTiming = false

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Lap Time Derivation

The reader derives lap times in priority order:

1. OfficialLapTime column (most accurate — from game engine)
2. Time delta: Points[^1].Time - Points[0].Time
3. Speed/distance estimate (last resort — least accurate)

The source used is stored in Lap.LapTimeSource for transparency.

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Track Outlines (Cache)

• WGS84 GeoJSON outlines: %LocalAppData%\ApexLab\track-outlines\*.json
• Aligned world-space outlines: %LocalAppData%\ApexLab\track-outlines\aligned\*.json
• Built-in fallbacks: Spa, Monza, Silverstone (SimCopilot.Storage/TrackOutlines/builtin-track-outlines.json)