Overview#
A company commander planning a night approach to an objective needs to know three things before the patrol moves: which routes keep the element below the ridge line and out of enemy observation, where the dead ground is in front of the objective that could conceal an enemy reserve, and whether the firing position planned for the support element has a clear line of sight to the breach point. Getting those answers from a paper map takes experience and time. The Terrain Analytical Modelling module provides them on demand, computed directly from digital elevation data.
The module delivers computational terrain analysis for military planning and operational decision-making. It computes line-of-sight between any two points, generates viewshed analyses from observer positions, extracts elevation profiles along routes, performs slope analysis for mobility assessment, and manages a registry of Digital Elevation Model (DEM) data sources. Terrain analysis results integrate directly with the effector matching engine for engagement feasibility assessment and with drone operations for flight route planning.
Open Standards#
- SRTM (NASA/NGA Shuttle Radar Topography Mission): The DEM registry natively ingests SRTM-derived elevation data at 30 m and 90 m resolution as a first-class source type, providing global baseline terrain coverage.
- WGS 84 / EPSG:4326: All georeferenced coordinates, bounding boxes, and observer/target positions are expressed in the WGS 84 geodetic datum (EPSG:4326), and great-circle distances are computed using the WGS 84 earth radius via the haversine formula.
- GeoTIFF (OGC/TIFF 6.0 extension): GeoTIFF is the default DEM interchange and storage format, used for both imported datasets and drone photogrammetry outputs registered in the model registry.
- GeoJSON (IETF RFC 7946): Bounding boxes and viewshed visible-area boundaries are represented as GeoJSON geometry objects, enabling direct consumption by mapping clients and overlays.
- ASPRS LAS (LiDAR Data Exchange Format): LiDAR point cloud derivatives are ingested via the LAS format, allowing high-resolution survey data from airborne or drone LiDAR sensors to be registered as DEM sources.
- GraphQL (June 2018 Specification): All terrain analysis operations, including line-of-sight, viewshed, elevation profile, and slope analysis, are exposed through a typed GraphQL API with queries and mutations defined against a Strawberry schema.
- OAuth 2.0 / OpenID Connect: Every GraphQL resolver enforces authentication and organisation-scoped authorisation via the platform's OAuth 2.0 / OIDC token pipeline, gating access to terrain data by both role and classification level.
Last Reviewed: 2026-04-02 Last Updated: 2026-04-14
Key Features#
Line-of-Sight Computation#
Compute line-of-sight between any two georeferenced points, accounting for terrain elevation, earth curvature, and atmospheric refraction. The result indicates whether a clear line-of-sight exists and, if obstructed, identifies the location and elevation of the obstructing terrain. Observer and target heights above ground level are configurable. Line-of-sight checks support engagement feasibility assessment, communications planning, and observation post siting.
Viewshed Analysis#
Generate 360-degree viewshed maps from any observer position, showing all terrain visible from that point at a specified observer height. The viewshed result is a raster overlay suitable for display on the operational map, with visible and non-visible areas clearly distinguished. Multiple viewshed layers can be combined to show cumulative coverage from a set of observation posts or sensor positions, identifying dead ground not covered from any position.
Elevation Profile Extraction#
Extract elevation profiles along any defined route or line, producing a distance-versus-elevation chart. Profiles support route planning by revealing terrain gradients, valleys, ridge crossings, and potential ambush points. The profile includes minimum and maximum elevation, total climb and descent, and identifies the highest and lowest points along the route.
Slope Analysis#
Compute slope gradients across an area of interest, classifying terrain into mobility categories. Slope data is presented as a colour-coded overlay distinguishing flat terrain, gentle slopes, moderate slopes, steep slopes, and impassable gradients. Slope thresholds are configurable based on vehicle type (wheeled, tracked, dismounted) to support mobility corridor identification and route planning.
DEM Model Registry#
Manage a registry of Digital Elevation Model data sources with varying resolution and coverage. Supported DEM types include SRTM (global coverage at 30m and 90m resolution), commercial satellite-derived DEMs, drone photogrammetry outputs, and LiDAR point cloud derivatives. The system automatically selects the highest-resolution available DEM for a given area of interest, with fallback to lower-resolution sources. Analysts can upload and register new DEM datasets for specific areas of operation.
Terrain Data Caching#
Frequently accessed terrain analysis results are cached to support real-time query performance. Cache invalidation occurs when new DEM data is registered for an area, ensuring analysis results always reflect the most current terrain data available.
Use Cases#
- Fire Support Planning: Compute line-of-sight from candidate firing positions to target areas, identifying positions with clear fields of fire and those masked by terrain.
- Observation Post Siting: Generate viewshed analyses from candidate OP locations to maximise surveillance coverage while identifying dead ground that requires alternative sensor coverage.
- Route Planning: Extract elevation profiles and slope analysis along candidate routes to identify the most suitable axis of advance for specific vehicle types.
- Drone Mission Planning: Compute terrain clearance profiles along planned drone flight paths, ensuring safe altitude margins above ground level throughout the route.
- Sensor Placement Optimisation: Combine viewshed and acoustic coverage analyses to identify optimal sensor network configurations that minimise blind spots.
- Engagement Feasibility: Provide the effector matching engine with line-of-sight data to assess whether a candidate effector has a clear engagement path to the target.
Integration#
- Effector Matching Engine: Provides line-of-sight feasibility data as an input to the multi-factor engagement scoring algorithm.
- Drone Operations Management: Supplies elevation data for terrain clearance during flight planning and route deconfliction.
- Acoustic Sensor Network: Terrain masking data informs acoustic coverage zone planning.
- 3D Terrain Visualisation: Analysis results (viewsheds, slope overlays, elevation profiles) are rendered on the 3D terrain map.
- Offline Maps: DEM data is included in offline map packages for disconnected terrain analysis.
GraphQL: terrainModels, terrainStats, terrainElevation (queries); registerTerrainModel, computeLineOfSight, computeViewshed, getElevationProfile, computeSlopeAnalysis (mutations).