DCS Reference: Air Defences
This resource is for players and mission designers to know the capabilities of and set up fully-featured and functional SAM groups using the many various units available under the “Air defence” vehicle category in the DCS mission editor.
Each block describes the system as a whole, the ground units it consists of, the dependencies between these units, and some key performance figures (in most cases data-mined from the game files, but in some instances gathered from in-game tests or wiki-based). In addition, optional units and decorative static objects that would complement the system and make them closer to the real setup are listed, even if these units generally serve no added function. The only exception is ammunition-providing M818 and Ural trucks that effectively give nearby units (within 200m) infinite ammunition capacity. These types of “warehouse” units will have a black circle in the mission editor to signify the range within which they provide ammunition for nearby units.
Note that maximum altitudes can be a bit unreliable due to the interaction between maximum sensor elevation, sensor range, and missile flight capabilities. While the maximum altitude may seem sufficient on some systems, it is often a lot lower in practice because there is a rather narrow band between where the missile still has energy enough to climb, and where the (usually) radar is still able to track a target. For maximum skylord murderness, make sure the altitude capabilities are ridiculously above where the target is expected to fly.
- All SAM components must be in the same group in the Mission Editor in order to function.
- All radar-guided SAMs require a search radar (SR), a tracking radar (TR), and launching capabilities.
- In many systems, search and tracking are combined into Search-and-Track Radar (STR) units. Those systems can often add a separate SR to extend detection range, but that unit is never mandatory to make the system work.
- IR-guided systems obviously do not require SR or TR units, but can occasionally be supplemented by them to improve detection ranges and response time in exchange for losing the surprise factor of an IR launch.
- Some mobile systems, in particular, combined all three core components into one Transporter, Erector, Launcher and Radar (TELAR) vehicle that can operate completely independently.
- All SAMs have limited ammunition.
- Placement of an Ammunition truck (such as the Ural-375) of any kind nearby a launcher will allow it to reload.
- In DCS, most multi-unit SAMs are able to spread units as far as 25nm from each other, enabling dispersed configurations. This is not particularly realistic for many sites in their native time periods, which had the challenges of limited cable runs and electrical power distributions. However, more modern scenarios can believably distribute sites as far as 20nm with "datalink upgrade" related handwaves. Pilots should be aware of this and recognize that missile launches from such sites can approach from angles other than the tracking emitter (including, quite dangerously, from directly below).
Detection, alarm states, and command units
Many systems include some sort of optional commander or extended-range/early-warning unit. The functionality these units is, and always has been, quite vague, but will often offer some improvement in detection over the system's base units. For systems where the command unit is mandatory, or semi-optional, it often offloads some tasks from sensor and launch units to increase the speed at which targets can be engaged.
- A SAM must be in a “Red” alarm state in order to ready its weapons and fire.
- A group can be set explicitly to a “Green” or “Red” state through advanced waypoint options — the default is “Auto”, where the group transitions from one to the other depending on the presence of any detected enemies.
- Once enemies are within a unit's detection range, it will ready itself, which takes a different amount of time depending on the unit.
- For some systems (e.g. the SA-11), command units “buffer” target acquisitions, drastically reducing the time for a launcher to switch from one target to the next — a launcher unit can keep engaging its locked target while the search radar finds a new one and once the target is destroyed, the launcher can quickly transition to a fresh one without going through the full acquisition process.
A full list of which countries have access to what units can be found in the countries list.
A note on stats
Most numerical values have been taken directly from the DCS database Lua files, and where possible confirmed in the mission-editor and in-game. Even so a few caveats are necessary:
- There are often state transition pauses that add extra delays, for instance between a launcher expending its last missile and subsequently starting its reload/rearm procedure. As such, all numbers, but timers in particular, should be considered upper or lower bounds rather than the exact value a unit will use.
- Unit skill can affect to what extent these numbers can be matched by the AI, leading to a fair amount of additional variation and divergence.
- Testing suggests that player-controlled units also have a “skill level” of sorts attached that creates similar effects. Reloading times, for instance, will commonly be 10% longer if the unit is directly controlled by a player via Combined Arms.
- Some database file overload certain statistics, especially in regards to sensor capabilities, in ways that are not always easy to follow — the stats provided come from a relatively shallow reading of those files.
- Some stats, again especially related to sensors, are subject to more in-depth mechanics related to a target's relative detectability and the sensor's ability to pick on a standard normalised targets. In particular, IR lock-on ranges can not reliably be defined since they rely on so many external factors.
- Similarly, edge cases for detection (e.g. radars picking up and engaging incoming bombs or missiles) can go either way, and can give rise to unexpected behaviours. Notably, bombs have no clearly defined radar cross-section nor heat signature, yet can sometimes be seen being engaged even by IR SAM systems(!).
- Some data are locked behind encrypted files in DLC, most notably the WWII Assets Pack, and thus cannot be extracted and determined with any accuracy beyond hints in the mission editor and error-prone in-game testing.
Scripts and Shenanigans
This script adds your SAM groups to an Integrated Air defence System, which minimally consists of an Early Warning Radar (EWR) site (a lone long range radar or a long range SAM, ideally) and SAMs operating under its coverage. SAMs under EWR coverage will refrain from turning on their emitters until hostile aircraft reach a (configurable) range, reducing time for victims to react before being fired upon, as well as reducing vulnerability to SEAD. This system also enables a chance based HARM detection ability. SAMs that normally fire upon HARMs will, others will simply turn off their radars. All of these capabilities are configurable, allowing the script to be tuned to the author's taste.
- Each sam group must have a single SAM.
- The search radar must be the first unit in the group.
An IADS can be degraded by taking out its search radars, which generally remain online.
- Should also be optically guided, but is implemented in DCS as radar-only.