patrickfleith/GOCE-satellite-telemtry

Utilisation of this data is subject to European Space Agency's Earth Observation Terms and Conditions. Read T&C here

This is Dataset Version 3 - Updates may be done following feedback from the machine learning community.

Dataset Description

This dataset contains 327 time series corresponding to the temporal values of 327 telemetry parameters over the life of the real GOCE satellite (from March 2009 to October 2013). It consists both the raw data and Machine-Learning ready-to-use resampled data:

• The raw values (calibrated values of each parameter) as {param}_raw.parquet files (irregular)
• Resampled and popular statistics computed over 10-minutes windows for each parameter as {param}_stats_10min.parquet files.
• Resampled and popular statistics computed over 6-hours windows for each parameter as {param}_stats_6h.parquet
• metadata.csv list of all parameters with description, subsystem, first and last timestamp where a value is recorded, fraction of NaN in the calculated statistics and the longest data gap.
• mass_properties.csv: provides information relative to the satellite mass (for example the remaining fuel on-board).

Why is it a good dataset for time series forecasting?

• Real-world: the data originates from a real-world complex engineering system
• Many variables: 327 allowing for multivariate time series forecasting.
• Variables having engineering values and units (Volt, Ampere, bar, m, m/s, etc...). See the metadata
• Different and irregular sampling rates: some parameters have a value recorded every second, other have a value recorded at a lower sampling rate such as every 16 or 32s. This is a challenge often encountered in real-world systems with sensor records that complexity the data pipelines, and input data fed into your models. If you want to start easy, work with the 10min or 6h resampled files.
• Missing Data and Large Gaps: you'll have to drop many parameters which have too much missing data, and carefully design and test you data processing, model training, and model evaluation strategy.
• Suggested task 1: forecast 24 hrs ahead the 10-min last value given historical data
• Suggested task 2: forecast 7 days ahead the 6-hour last value given historical data

License

European Space Agency's Earth Observation Terms and Conditions. Read T&C here*

About the GOCE Satellite

The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE; pronounced ‘go-chay’), is a scientific mission satellite from the European Space Agency (ESA).

Objectives

GOCE's primary mission objective was to provide an accurate and detailed global model of Earth's gravity field and geoid. For this purpose, it is equipped with a state-of-the-art Gravity Gradiometer and precise tracking system.

Payloads

The satellite's main payload was the Electrostatic Gravity Gradiometer (EGG) to measure the gravity field of Earth. Other payload was an onboard GPS receiver used as a Satellite-to-Satellite Tracking Instrument (SSTI); a compensation system for all non-gravitational forces acting on the spacecraft. The satellite was also equipped with a laser retroreflector to enable tracking by ground-based Satellite laser ranging station.

The satellite's unique arrow shape and fins helped keep GOCE stable as it flew through the thermosphere at a comparatively low altitude of 255 kilometres (158 mi). Additionally, an ion propulsion system continuously compensated for the variable deceleration due to air drag without the vibration of a conventional chemically powered rocket engine, thus limiting the errors in gravity gradient measurements caused by non-gravitational forces and restoring the path of the craft as closely as possible to a purely inertial trajectory.

Thermal considerations

Due to the orbit and satellite configuration, the solar panels experienced extreme temperature variations. The design therefore had to include materials that could tolerate temperatures as high as 160 degC and as low as -170 degC.

Due to its stringent temperature stability requirements (for the gradiometer sensor heads, in the range of milli-Kelvin) the gradiometer was thermally decoupled from the satellite and had its own dedicated thermal-control system.

Mission Operations

Flight operations were conducted from the European Space Operations Centre, based in Darmstadt, Germany.

It was launched on 17 March 2009 and came to and end of mission on 21 October 2013 because it ran out of propellant. As planned, the satellite began dropping out of orbit and made an uncontrolled re-entry on 11 November 2013

Orbit

GOCE used a Sun-synchronous orbit with an inclindation of 96.7 degree, a mean altitude of approximately 263 km, an orbital period of 90 minutes, and a mean local solar time at ascending node of 18:00.

Resources

• Data Source
• ESA GOCE Mission Page
• Quality Control Reports are available in three different varieties covering quality monitoring of science and calibration products, providing monthly overviews of the health of the SSTI and EGG instrument and product quality, and any anomalies that may affect the quality of data acquired:
  • EGG
  • SSTI
• GOCE EO Portal with Satellite Technical Details
• python library for astrodynamics computation: poliastro but be aware that it is no longer maintained.
• Resources on orbital mechanics

Acronym List

Here is an acronym lists which may be useful to understand the names of the available telemetry parameters, subsystems and parameter descriptions.

• GOCE: Gravity field and steady-state Ocean Circulation Explorer
• GCD: Gradiometer Calibration Device
• EGG: (Electrostatic Gravity Gradiometer) - Main Instrument: Provided gravity gradients.
• SSTI: (Satellite-to-Satellite Tracking Instrument): Provided GPS observations.
• MGM: (3-axis Magnetometer): 3 Magnetometers used for magnetic torquer control and as rate sensors.
• STR: (Star trackers): 3 Star trackers for precise pointing knowledge
• LRR: (Laser Retro-Reflector): Passive optical reflector; enabled satellite laser ranging by ground-based stations.
• DFACS: (Drag-Free and Attitude Control System)
• POD: Precise orbit determination
• LORF: Local Orbital Reference Frame
• SGG: Satellite Gravity Gradiometer
• COP: Centre of Pressure / Centre of Mass
• CFRP: Carbon Fibre Reinforced Plastic
• AOCS: Attitude and Orbit Control System
• IPA / ITA: Ion Propulsion Assembly / Ion Thruster Assembly
• ARFS: Avionics and Radio Frequency Subsystem
• CDMU: Command & Data Management Unit
• PASW: Platform Application Software
• RCS: Reaction Control System
• CESS: Coarse Earth and Sun Sensor

Pointing Modes

• CPM: (Coarse Pointing Mode)
• ECPM: (Extended Coarse Pointing Mode)
• FPM: (Fine Pointing Mode)
• DFM:(Drag-Free Mode)