PX4 ULog

Nominal’s first-party extractor reads PX4 ULog flight logs (.ulg and .ulog). Each topic field becomes a channel, such as vehicle_local_position.vx. A topic logged by more than one instance keeps the instance in its name, such as sensor_accel_0.x.

Before you start

Enable the extractor in your workspace:

1. In the Nominal app’s sidebar, open Data > File extractors.

2. Click NEW EXTRACTOR > Native extractor.

3. Choose PX4 ULog and click ENABLE EXTRACTOR.

Upload a file

Nominal app

1. In the sidebar, click + (New), then Upload data.

2. On the File extraction card, click SELECT and choose PX4 ULog.

3. Click SELECT A DESTINATION and choose Standalone dataset. Pick a dataset, or click NEW DATASET, enter a name and click CREATE DATASET.

4. Next to INPUT_FILE, click Select file and choose the .ulg file.

5. Click CONFIRM & INGEST.

Python

Select the extractor’s row on the File extractors page to see its RID.

from nominal.core import NominalClient

client = NominalClient.from_profile("default")
extractor = client.get_containerized_extractor("<EXTRACTOR_RID>")
dataset = client.create_dataset("Flight 42")
job = dataset.add_containerized(extractor, sources={"INPUT_FILE": "flight.ulg"})
for file in job.as_files_ingested():  # waits for ingestion
    print(file.name, file.ingest_status.name)

Options

Setting	Nominal app	Python	Extractor variable
Convert only these topics, such as vehicle_attitude,sensor_combined, in upper or lower case	Topic filter	TOPIC_FILTER in arguments	TOPIC_FILTER
A tag on every point	Tags	tags	—

Logs without a GPS fix

The extractor moves timestamps from time since boot to UTC using the log’s GPS fix, from vehicle_gps_position or sensor_gps. A log with no GPS fix keeps boot-relative times. From Python, give the time the log started, continuing the Python example above:

from datetime import datetime, timezone

from nominal import ts

started = datetime(2026, 1, 1, 12, 0, tzinfo=timezone.utc)
job = dataset.add_containerized(
    extractor,
    sources={"INPUT_FILE": "bench.ulg"},
    timestamp_column="timestamps",
    timestamp_type=ts.Relative("nanoseconds", start=started),
)

Convert a log yourself

To convert a log to CSV files with the Python client and upload those instead, see PX4 ULog in the Python client’s guides.