CSV Log Columns Reference¶

Complete reference for all columns in OnSpeed SD card log files. Data is logged at 50 Hz by default (configurable to 1, 2, 10, 25, 50, 200, or 416 Hz via the web interface). 416 Hz logs every IMU sample; lower rates downsample.

Columns are written in groups, in this order: (1) base core columns (timeStamp through Decel), (2) optional raw IMU companion columns (only when logging at the 416 Hz IMU rate, VerticalG_raw through Decel_raw), (3) optional Boom columns (when Boom is enabled), (4) optional EFIS columns (when an EFIS is configured), (5) derived core columns (EarthVerticalG through CoeffP), (6) EKFQ diagnostic columns, (7) tail-optional flapsRawADC. Parse by column name from the header line — index positions shift when optional blocks are enabled.

Plain name = smoothed, _raw = raw IMU

The motion channels (VerticalG, LateralG, ForwardG, RollRate, PitchRate, YawRate, Sideslip) carry the AHRS-smoothed value — bias-corrected and tau-smoothed — following the industry convention used by Garmin and Dynon. When the log runs at the 416 Hz IMU rate, a matching _raw companion column carries the raw, un-rotated IMU body-frame value for each. At any lower (downsampled) rate the raw sample would be aliased noise, so the _raw columns are omitted.

Core Columns — Base¶

Column	Units	Description
`timeStamp`	ms	Milliseconds since power-on
`timeStampUs`	µs	Microseconds since power-on (co-located with `timeStamp`)
`Pfwd`	counts	Pitot pressure, bias subtracted (14-bit ADC)
`PfwdSmoothed`	counts	Pitot pressure after median + running-average smoothing
`P45`	counts	AOA pressure, bias subtracted (14-bit ADC)
`P45Smoothed`	counts	AOA pressure after median + running-average smoothing
`PStatic`	mbar	Static (barometric) pressure
`Palt`	ft	Pressure altitude (ISA 1013.25 hPa reference; no Kollsman/QNH correction). Computed each row from `PStatic`.
`IAS`	knots	Indicated airspeed
`AngleofAttack`	degrees	Computed AOA from pressure polynomial
`flapsPos`	degrees	Detected flap position (snapped to the nearest configured detent)
`DataMark`	0–99	Pilot data annotation (wraps at 100)
`OAT`	°C	Outside air temperature
`TAS`	knots	True airspeed
`imuTemp`	°C	IMU330 sensor temperature
`VerticalG`	G	Vertical acceleration (body Z-axis), AHRS-smoothed
`LateralG`	G	Lateral acceleration (body Y-axis), AHRS-smoothed
`ForwardG`	G	Forward acceleration (body X-axis), AHRS-smoothed
`RollRate`	deg/s	Roll angular rate (gyro), AHRS-smoothed
`PitchRate`	deg/s	Pitch angular rate (gyro), AHRS-smoothed
`YawRate`	deg/s	Yaw angular rate (gyro), AHRS-smoothed
`Pitch`	degrees	Pitch angle (AHRS output, smoothed)
`Roll`	degrees	Roll angle (AHRS output, smoothed)
`Sideslip`	degrees	Sideslip angle β (kinematic, AHRS-smoothed)
`Decel`	kt/s	IAS deceleration rate, smoothed (`SmoothChannel::DecelKtPerSec` output). Negative = decelerating. Same value the box ships on the display wire.

Raw IMU Columns (416 Hz logging only)¶

Present only when the log runs at the 416 Hz IMU rate. Each carries the raw, un-rotated IMU body-frame value for the matching smoothed channel above (see the note at the top of this page).

Column	Units	Description
`VerticalG_raw`	G	Raw vertical acceleration (body Z-axis)
`LateralG_raw`	G	Raw lateral acceleration (body Y-axis)
`ForwardG_raw`	G	Raw forward acceleration (body X-axis)
`RollRate_raw`	deg/s	Raw roll angular rate (gyro)
`PitchRate_raw`	deg/s	Raw pitch angular rate (gyro)
`YawRate_raw`	deg/s	Raw yaw angular rate (gyro)
`Sideslip_raw`	degrees	Raw kinematic sideslip angle β
`Decel_raw`	kt/s	Raw IAS deceleration rate — the SavGol(15) IAS-derivative output before `DecelKtPerSec` smoothing. The un-smoothed companion to `Decel`, for offline filter tuning.

Core Columns — Derived¶

Appended after any optional Boom/EFIS columns.

Column	Units	Description
`EarthVerticalG`	G	Vertical acceleration in Earth frame
`FlightPath`	degrees	Flight path angle = arcsin(VSI/TAS)
`VSI`	fpm	Vertical speed, smoothed by the active AHRS algorithm's vertical channel
`Altitude`	ft	Pressure altitude, smoothed by the active AHRS algorithm's vertical channel. Same quantity as `Palt`, smoothed with vertical accel. Not MSL — ISA reference, no Kollsman/QNH correction.
`DerivedAOA`	degrees	SmoothedPitch − FlightPath
`CoeffP`	—	Pressure coefficient (P45/Pfwd)

EKFQ Diagnostic Columns¶

Always present. The values are finite when the AHRS algorithm is EKFQ (the default), which estimates these states, and written as nan under Madgwick, which does not.

Column	Units	Description
`ekfBpDps`	deg/s	Roll-rate gyro bias
`ekfBqDps`	deg/s	Pitch-rate gyro bias
`ekfBrDps`	deg/s	Yaw-rate gyro bias
`ekfBAzMps2`	m/s²	Earth-frame vertical-acceleration bias
`ekfBetaDeg`	degrees	Sideslip angle β (EKFQ state)
`ekfYawDeg`	degrees	Yaw angle

Boom Probe Columns (When Boom Enabled)¶

Column	Units	Description
`boomStatic`	counts¹	Static pressure from boom
`boomDynamic`	counts¹	Dynamic (pitot) pressure from boom
`boomAlpha`	counts¹	Angle of attack from boom
`boomBeta`	counts¹	Sideslip angle from boom
`boomIAS`	knots	Indicated airspeed from boom
`boomAge`	ms	Time since last boom data packet

¹ Raw ADC counts by default. When BOOMCONVERTDATA=true the firmware applies the polynomial calibration curves in onspeed_core/BoomConvert.h and writes physical units (PSI for boomStatic / boomDynamic, degrees for boomAlpha / boomBeta). BOOMCONVERTDATA defaults to false.

EFIS Columns — Dynon/Garmin/MGL¶

When EFIS type is ADVANCED, DYNOND10, GARMING5, GARMING3X, or MGL:

Column	Units	Description
`efisIAS`	knots	IAS from EFIS
`efisPitch`	degrees	Pitch angle from EFIS
`efisRoll`	degrees	Roll angle from EFIS
`efisLateralG`	G	Lateral acceleration from EFIS
`efisVerticalG`	G	Vertical acceleration from EFIS
`efisPercentLift`	%	Percent lift / AOA (0–99%)
`efisPalt`	ft	Pressure altitude from EFIS
`efisVSI`	fpm	Vertical speed from EFIS
`efisTAS`	knots	True airspeed from EFIS
`efisOAT`	°C	Outside air temperature from EFIS
`efisFuelRemaining`	gal	Fuel remaining
`efisFuelFlow`	gph	Fuel flow rate
`efisMAP`	inHg	Manifold absolute pressure
`efisRPM`	rpm	Engine RPM
`efisPercentPower`	%	Computed percent power
`efisMagHeading`	degrees	Magnetic heading
`efisAge`	ms	Time since last valid EFIS packet
`efisTime`	ms	Timestamp from EFIS

EFIS Columns — VectorNav VN-300¶

When EFIS type is VN-300:

Column	Units	Description
`vnAngularRateRoll`	rad/s	Roll rate
`vnAngularRatePitch`	rad/s	Pitch rate
`vnAngularRateYaw`	rad/s	Yaw rate
`vnVelNedNorth`	m/s	North velocity (NED frame)
`vnVelNedEast`	m/s	East velocity (NED frame)
`vnVelNedDown`	m/s	Down velocity (NED frame)
`vnAccelFwd`	m/s²	Forward acceleration
`vnAccelLat`	m/s²	Lateral acceleration
`vnAccelVert`	m/s²	Vertical acceleration
`vnYaw`	degrees	Yaw angle
`vnPitch`	degrees	Pitch angle
`vnRoll`	degrees	Roll angle
`vnLinAccFwd`	m/s²	Linear forward acceleration
`vnLinAccLat`	m/s²	Linear lateral acceleration
`vnLinAccVert`	m/s²	Linear vertical acceleration
`vnYawSigma`	rad	Yaw uncertainty
`vnRollSigma`	rad	Roll uncertainty
`vnPitchSigma`	rad	Pitch uncertainty
`vnGnssVelNedNorth`	m/s	GPS north velocity
`vnGnssVelNedEast`	m/s	GPS east velocity
`vnGnssVelNedDown`	m/s	GPS down velocity
`vnWindSpd`	kt	Horizontal wind speed (derived; empty when below 30 KIAS or no GPS fix)
`vnWindDir`	degrees	Wind "from" direction in [0, 360), same frame as `vnYaw` (true if VN-300 has WMM declination configured, magnetic otherwise)
`vnWindVertical`	kt	Vertical wind component, positive = updraft
`vnGnssLat`	degrees	GPS latitude
`vnGnssLon`	degrees	GPS longitude
`vnEstAltFt`	feet	INS-estimated altitude from Common.Position (sensor-fused GPS+IMU) — filter on `vnGPSFix`
`vnGPSFix`	enum	GPS fix quality
`vnDataAge`	ms	Time since last VN-300 packet
`vnTimeStartupNs`	ns	Per-sample timestamp from the VN-300 Common group: nanoseconds since VN-300 boot (TXCO ±20 ppm). Always advancing, no GPS dependency. At 400 Hz output, consecutive rows differ by ~2,500,000 ns.
`vnTimeGpsNs`	ns	Per-sample timestamp: nanoseconds since GPS epoch (1980-01-06 UTC, minus accumulated GPS leap seconds — currently 18 s ahead of UTC). Valid only when `vnTimeStatus & 0x02` (dateOk) is set.
`vnTimeStatus`	bit flags	VN-300 TimeStatus byte (UM005 §5.5.10). `bit0` = timeOk (GpsTow valid), `bit1` = dateOk (`vnTimeGpsNs` valid — GPS week resolved), `bit2` = utcTimeValid.

Tail-Optional Columns¶

Appended at the very end of every row, after the EKFQ diagnostic columns. Emitted only when the session captures the raw flap-pot ADC. Parsers must look up by name from the header line rather than by fixed position.

Column	Units	Description
`flapsRawADC`	counts	Raw flap-lever pot ADC reading (uint16, typically 0–4095 on the 12-bit ADC). Lets replay and analysis tools reproduce the L/Dmax pip slide across detent transitions; consumers interpolate the pip lever-end-to-end using this value against the configured `<FLAPPOTPOSITIONS>` boundaries.