Specific Operational Risk Assessment (SORA)

Via supports both JARUS V2.5 and the UK SORA specific implementation of SORA. These can be switched between in the Web Application on the “SORA” tab.

To appropriately use Via please familiarise yourself with the required implementation.

For bespoke SORA training please contact us at: via@volantautonomy.com

Compliance

Via uses SORA as an input to the Flyable Region that is produced based on the combination of all restrictions on a Flightplan. The Flightplan and it’s flightpath are then checked against this Flyable Region ensuring compliance.

Specifying a SORA Classification

For those that are already aware of their expected SORA operating permissions, Via offers the ability to specify and apply them to a Flightplan directly by means of creating a SORA Classification. A SORA Classification contains the following key information:

• Details about the aircraft being used (maximum cruise speed and characteristic dimension).
• The Semantic Model: Flight Geography and Contingency buffer (derived from the Flightplan parameters) and the intended Ground Risk Buffer (to provide safe termination distance if the contingency volume is breached).
• Any ground risk and air risk mitigations to be applied.
• The Final Ground Risk Classification (GRC) and Initial Air Risk classifications (ARC) as derived from the desired Safety Insurance Integrity Level (SAIL).
• The containment robustness used to ensure compliance with population in the adjacent area.
• A Controlled Ground Area or Atypical Airspace to consider if applicable

Note

A Classification requires the Final GRC and the Initial ARC to allow Via to more accurately determine the operating environment as a SAIL can be achieved through multiple combinations of GRC and ARC.

Flightplan Reports

When the expected operating permissions are unknown, Via provides an exploratory capability which can determine the minimum required permissions for a given Flightplan. In doing this several key pieces of additional information can be retrieved that are important when preparing for a SORA application:

• The maximum overflown population density within the Operational Volume and hence the Intrinsic GRC
• The average population density overflown within the adjacent area which informs the containment robustness
• The operational limits for average population density overflown within the adjacent area and maximum permissible assembly size within 1km of the Operation Volume as required by the containment robustness level.

Caution

As the minimum SAIL is determined, often a higher containment robustness is required than may be desired for the Flightplan due the inverse relationship between SAIL and containment robustness.

Overlays

The Web Application supports understanding of the SORA framework by use of map overlays to display key information. These can be accessed using the display button in the bottom-left. Overlays are designed to give a better understanding of how the airspace and ground are categorised according to SORA by showing information such as:

• The Intrinsic GRC with the inclusion of any Controlled Ground Areas, and how it varies dependant on the choice of population source.
• The Final GRC to show how mitigations affect the Intrinsic GRC
• The Initial ARC and how it varies depending on the chosen SORA implementation and source for airspace classifications.
• SAIL and how it varies with both GRC and ARC.

Data Sources

Population Density

Via allows the use of various population density sources to suit different operational and regulatory requirements:

• Global Human Settlement Layer data sourced from EU’s Copernicus programme, for the year 2020. This provides an estimate of population at a resolution of 100m² across the entire globe.
• Eurostat GEOSTAT data sourced from a 2021 census. This provides data for EU countries at a resolution of 1km².
• UK Centre for Hydrology and Ecology Environmental Information Data Centre data based on the UK Office for National Statistics 2011 census. Variants for both residency and adjusted for locations during the working day are included. Data is available across the UK at a resolution of 1km².
• ONS England and Wales 2021 Census data derived from the density figures at an OA level and gridded according to the sum of densities weighted by the proportion of a grid cell occupied by the OA. Variants for residency and adjustments for locations during the working day and locations outside of the school term are included. Data is generated at 100m² and 1km² resolutions.

Data is re-projected and interpolated onto a square cartesian grid in UTM coordinates to work in the context of Via’s services. The value assigned to each cell during the reprojection is the largest value present in any of the cells of the source data it intersects. The values are normalised by source data cell area to derive a density value of people per square metre.