The individual terrain observations are now integrated into combined products: first the COO, then the MCOO, supplemented with weather and infrastructure analysis.
COO and MCOO
The Combined Obstacle Overlay combines all known natural and man-made obstacles into a single operational picture. Sources: topographic maps, digital terrain models, satellite imagery, engineer reconnaissance, UAV imagery, infrastructure databases, hydrographic data and reports.
The Modified Combined Obstacle Overlay expands the COO with what the terrain means for maneuver. The MCOO classifies terrain and identifies likely corridors, supporting COA development, wargaming, targeting, ISR planning and decision support.
| Classification | Characteristics | Consequence |
|---|---|---|
| GO | Good roads, open fields, gentle slopes, stable soil | Unrestricted movement — suitable for tanks, IFVs, logistics |
| SLOW-GO | Forest, broken terrain, small rivers, urban areas | Movement possible but reduced; requires engineer support and increased security |
| NO-GO | Swamps, deep rivers, cliffs, minefields, destroyed bridges | Movement (nearly) impossible without bridging or clearance |
Mobility classification is always relative to the unit type — NO-GO for tanks may be GO for infantry — and weather can flip it: 48 hours of rain turns GO fields into SLOW-GO.
Mobility corridors, avenues of approach and choke points
A mobility corridor is a strip of terrain that permits movement while avoiding major obstacles. Assess width, capacity, trafficability, cover, observability and vulnerability.
Corridors combine into avenues of approach: routes that let a force reach its objective while maintaining combat power. An AA weighs terrain, enemy observation, fire support, logistics, engineering and tempo.
Choke points — bridges, tunnels, mountain passes, intersections, ferry crossings — restrict movement and therefore often become NAIs or TAIs and candidate HVTs.
Weather analysis
Weather affects every operation: mobility, observation, weapon effectiveness, aviation, ISR and logistics. The four operational weather factors:
| Factor | Mainly affects |
|---|---|
| Visibility (fog, rain, snow, dust, smoke) | UAVs, optical sensors, observation posts, target acquisition |
| Wind | Smoke, UAV endurance, helicopters, precision fires |
| Temperature | Personnel, batteries, fuel consumption, vehicle reliability |
| Precipitation | River levels, cross-country mobility, roads, logistics |
The weather effects matrix summarizes the effect per side — fog gives the friendly attack concealment, but also denies the enemy his observation. Always assess weather together with terrain.
Infrastructure and the terrain effects matrix
Infrastructure analysis assesses roads, railways, airfields, bridges, ports, power grids, communications and fuel facilities. Key questions: can heavy vehicles use the bridge? Can damage be repaired? Are alternatives available? Which infrastructure is decisive?
Infrastructure becomes critical once its loss materially affects the operation — the only bridge across the river, the regional fuel depot, the airfield, the railway junction. Critical infrastructure often becomes HVT, HPT, NAI or TAI.
Finally, the terrain effects matrix summarizes per terrain feature what it means for both sides — not what is there, but what it does.
COO · MCOO · mobility overlay · mobility corridor analysis · terrain effects matrix · weather effects matrix · infrastructure assessment · key terrain assessment.
Air force example: weather and space effects
The four weather factors also apply in the air, but with different thresholds and an added dimension: the space environment.
| Factor | Effect on air operations |
|---|---|
| Ceiling & visibility | Minimum altitudes for CAS and low-level routes; fog closes airfields |
| Icing | Reduced aerodynamics, extra de-icing time on the ground |
| Jet stream | Affects flight time, fuel consumption and precision of high-altitude weapon releases |
| Space weather (solar activity) | Disrupts GPS accuracy, SATCOM and HF communications — critical for precision navigation and datalinks |
For air operations, the weather analysis is not complete without a space segment: a geomagnetic storm can hit GPS-guided weapons and satellite communications just as hard as fog hits an optical sensor.