Outer Hebrides Lidar Digital Surface Model at 25cm Resolution, 2019

A 2019 lidar survey commissioned by the Scottish Environment Protection Agency (SEPA) and flown by Bluesky International Ltd. The 25 cm resolution Digital Surface Model (DSM) covers approximately 200 km² of main settlement areas, including Stornoway, to improve topographic data for flood risk modelling. Data was captured at 16 points per square metre and processed using the OSGM15 geoid model and OSTN15 transformation.

Use Cases

• Coastal flood risk modelling based on high-resolution topographic data.
• Surface water flood risk assessment based on the detailed Digital Surface Model.
• Terrain analysis for infrastructure planning in the Outer Hebrides settlement areas.
• Validation and improvement of broader-scale elevation models using the 25cm resolution data.

Strengths

• High-resolution 25 cm Digital Surface Model derived from lidar.
• Survey conducted with 16 points per square metre density.
• Ground control areas show RMSE values ranging from 0.020m to 0.097m.
• Covers approximately 200 km² of key settlement areas.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and file size are unknown, which may limit suitability assessment.
• Data coverage is limited to main settlement areas, not the entire Outer Hebrides.

Provenance

Source

Scottish Environment Protection Agency (SEPA), collected by Bluesky International Ltd.

Collection Method

Aerial lidar survey.

Time Range

2019 (survey flown between June and September).

Freshness

Data reflects a 2019 survey; last update date for the dataset is unknown.

Geography

Outer Hebrides, Scotland, UK (approximately 200 km² of main settlement areas including Stornoway).