Radio observatory anomaly detection dataset
Full name: Radio observatory anomaly detection dataset

The ROAD dataset is made up of observations from the Low Frequency Array (LOFAR) telescope. LOFAR is comprised of 52 stations across Europe, where each station is an array of 96 dual polarisation low-band antennas (LBA) in the 10–90 MHz range and 48 or 96 dual polarisation high-band antenna antennas (HBA) in the 110–250 MHz range. The data are four dimensional, with the dimensions corresponding to time, frequency, polarisation, and station. dictate the array configuration (i.e. the number of stations used), the number of frequency channels (Nf), the time sampling, as well as the overall integration time (Nt) of the observing session. Furthermore, the dual-polarisation of the antennas results in a correlation product (Npol) of size 4.  The ROAD dataset contains ten classes that describe various system-wide phenomena and anomalies from data obtained by the LOFAR telescope. These classes are categorised into four groups: data processing system failures, electronic anomalies, environmental effects, and unwanted astronomical events as shown by the table below.

| **Category**            | **Description**                                    | **Band** | **Polarisation** | **Occurrence rate** | ** Num Samples** |
|--------------------------------|-------------------------------------------------------------|-------------------|---------------------------|------------------------------|--------------------------|
| Normal                         | All non-characterised effects                               | Both              | All                       | -                            | 4687                     |
| % Electric fence               | RFI emitted from electric fences                            | Low               | Cross                     | 64                           |
| **Data processing**       |                                                             |                   |                           |                              |                          |
| First order data loss          | Data loss from consecutive time and/or frequency channels   | Both              | All                       | 0.02                         | 146                      |
| Second order data loss         | Data loss from single frequency and/or single time channels | Both              | All                       | 0.04                         | 283                      |
| **Electronic systems**    |                                                             |                   |                           |                              |                          |
| High noise element             | High power disturbances caused by miscellaneous events      | Both              | All                       | 0.01                         | 88                       |
| Oscillating tile               | Amplifier going into oscillation                            | High              | All                       | 0.01                         | 56                       |
| **Astronomical events**   |                                                             |                   |                           |                              |                          |
| Source in side-lobes           | A-team source passing through side-lobes                    | High              | All                       | 0.06                         | 446                      |
| Galactic plane                 | Galactic plane passing through the main lobe of the antenna | Both              | Cross                     | 0.08                         | 550                      |
| Solar storm                    | Strong emissions from the sun                               | Low               | All                       | 0.02                         | 147                      |
| **Environmental effects** |                                                             |                   |                           |                              |                          |
| Lightning                      | Lightning storm                                             | Both              | All                       | 0.06                         | 389                      |
| Ionospheric RFI reflections    | RFI reflected from the ionosphere                           | Low               | All                       | 0.04                         | 261                      |

Introducing paper: The ROAD to discovery: machine learning-driven anomaly detection in radio astronomy spectrograms