If exactly one matching nuScenes input set is present under scenarios, that scene is used. Otherwise the bundled scene_pose.json, scene_ms_imu.json, and scene_zoe_veh_info.json set is used.

Throws

std::filesystem::filesystem_error If scenarios cannot be iterated.

std::runtime_error If the bundled set is needed but missing.

`LoadScene`

Load the selected pose, IMU, and wheel-speed streams.

Signature

source

LoadedScene LoadScene(const SceneInputs& scene_inputs);

Inputs

scene_inputs: Selected pose, IMU, and wheel-speed file paths.

Output

Loaded pose, IMU, and wheel-speed samples.

Non-obvious behavior

If exactly one final pose sample occurs after the last IMU sample, it is dropped during load.

Throws

std::runtime_error If a required selected file cannot be opened, or if parsing a selected file fails.

GPS Generation

Generate synthetic GPS samples from pose samples.

`GenerateGpsSamplesFromPose`

Generate synthetic GPS samples from the loaded pose stream.

Signature

source

std::vector<GpsSample> GenerateGpsSamplesFromPose(
    const std::vector<PoseSample>& pose_samples);

Inputs

pose_samples: Loaded pose samples.

Output

Generated GPS samples.

Non-obvious behavior

The first pose sample is always kept. Later pose samples are kept only after at least 100 ms have elapsed since the last kept sample. Each kept sample becomes one noisy horizontal GPS measurement in the global frame.

Initialization

Compute the startup state used to begin live filtering.

`ComputeStartupInitialization`

Compute the startup initialization from IMU, GPS, and wheel-speed samples.

Signature

source

std::optional<StartupInitialization> ComputeStartupInitialization(
    const std::vector<ImuSample>& imu_samples,
    const std::vector<GpsSample>& gps_samples,
    const std::vector<WheelSpeedSample>& wheel_speed_samples);

Inputs

imu_samples: Loaded IMU samples.
gps_samples: Generated GPS samples.
wheel_speed_samples: Loaded wheel-speed samples.

Output

The startup handoff state, or std::nullopt when startup never reaches a state suitable for handoff.

Non-obvious behavior

The returned object contains the initial state together with the first IMU and GPS indices for the live post-startup run.

`TraceStartupInitialization`

Trace the startup evaluation across growing GPS prefixes.

Signature

source

StartupTraceResult TraceStartupInitialization(
    const std::vector<PoseSample>& pose_samples,
    const std::vector<ImuSample>& imu_samples,
    const std::vector<GpsSample>& gps_samples,
    const std::vector<WheelSpeedSample>& wheel_speed_samples);

Inputs

pose_samples: Loaded pose samples used for truth lookup.
imu_samples: Loaded IMU samples.
gps_samples: Generated GPS samples.
wheel_speed_samples: Loaded wheel-speed samples.

Output

The per-prefix startup trace and optional final handoff state.

Non-obvious behavior

The returned trace records the quantities the startup code computes for each tested GPS prefix. If startup succeeds, the trace also includes the resulting handoff state.

Runtime Loop

Run the post-startup ESKF loop and collect in-memory results.

`RunEskfLoop`

Run the post-startup ESKF loop and collect the data needed for output writing.

Signature

source

EskfRunResult RunEskfLoop(const LoadedScene& loaded_scene,
                          const std::vector<GpsSample>& gps_samples,
                          const StartupInitialization& startup_initialization);

Inputs

loaded_scene: Loaded pose and IMU streams.
gps_samples: Generated GPS samples.
startup_initialization: Startup state and handoff indices.

Output

In-memory log rows and RMSE summary values.

Non-obvious behavior

The returned rows match the CSV content, one row per GPS update.

Throws

std::runtime_error If a GPS update time has no matching pose sample, if no GPS updates are processed, or if the IMU stream ends before the last GPS update is handled.

Outputs

Write run artifacts and the successful-run summary.

`WriteGpsJson`

Write the generated synthetic GPS samples to output/gps.json.

Signature

source

std::filesystem::path WriteGpsJson(const std::vector<GpsSample>& gps_samples);

Inputs

gps_samples: GPS samples used during the run.

Output

Path of the written JSON file.

Throws

std::filesystem::filesystem_error If the output directory cannot be created.

std::runtime_error If output/gps.json cannot be opened for writing.

`WriteEskfSimLogCsv`

Write one CSV row per GPS update to output/eskf_sim_log.csv.

Signature

source

std::filesystem::path WriteEskfSimLogCsv(const EskfRunResult& run_result);

Inputs

run_result: In-memory result from the runtime loop.

Output

Path of the written CSV file.

Throws

std::filesystem::filesystem_error If the output directory cannot be created.

std::runtime_error If output/eskf_sim_log.csv cannot be opened for writing.

`PrintRunSummary`

Print the successful-run summary.

Signature

source

void PrintRunSummary(const EskfRunResult& run_result,
                     const std::filesystem::path& log_path,
                     std::ostream& out);

Inputs

run_result: In-memory result from the runtime loop.
log_path: Path of the written CSV log.
out: Stream to receive the summary.

Non-obvious behavior

The summary reports the number of GPS updates, the raw GPS horizontal RMSE, the ESKF horizontal RMSE, and the written log path.