We've detected a surface contact, but we have no clues as to its identity. Active sensors like radar and active sonar send out energy and analyze the return to detect objects. They are excellent at detecting contacts and determining their location, speed, heading, altitude--However, with the exception of some very high-end systems, they are unable to determine the identity of the contacts they detect. This is where passive sensors like visual, ESM and passive sonar come in. Passive sensors do not send out energy, but analyse energy that is emitted by other platforms in order to detect and classify them. Passive sensors are somewhat less effective at determining the exact position of a contact, but they are excellent at classifying and identifying contacts.

In this tutorial we will be using radar to detect surface contacts, and then using visual sensors to identify them. Let's take a look at the sensor types we have available:

Mk1 Eyeball:All ships, aircraft, land units and submarines with a crew automatically keep a lookout using the naked eye; the Mk1 Eyeball (submarines use periscopes at periscope depth and have bridge lookouts while on the surface).

The ability of the Mk1 Eyeball to detect other ships, aircraft and submarines is dependent on time of day, weather, and sea state as well as the size, distance, and speed of the target platform amongst other factors.

Under certain conditions, the Mk1 Eyeball can make detections at very long ranges, e.g. a lookout on a surface ship can spot an aircraft many miles away if the aircraft is contrailing, or conversely a lookout in an aircraft may spot a ship at a very long distance if the ship is leaving a wake. Both of these specific situations, and many others, are modelled in Command.

Magnified Optics / Electro-Optical (EO): The most basic magnified optic sensor is the binoculars, allowing detection, classification and identification of contacts at longer ranges than the Mk1 Eyeball, without improving the ability to see at night, or through fog, rain or smoke. EO sensors include television (TV) cameras, and charge-coupled devices (CCD). There are a variety of these sensors in the Command database, each with their own characteristics. Some are great at searching, some are great at classifying contacts detected with other sensors, and some are good at both.

Low Light Level TV (LLTV) / Night Vision Goggles (NVG): LLTV and NVG sensors amplify existing light to produce an image that is visible to the human eye. NVGs are typically used on smaller platforms such as tactical aircraft, land units or small boats and allow improved detection and classification of contacts under low light conditions. LLTV sensors usually include a degree of magnification and are often found on ships and larger aircraft.

Infra-Red (IR): IR sensors detect heat, allowing them to detect contacts irrespective of ambient light level. IR sensors are able to effectively see through smoke, fog and precipitation--although thick smoke or precipitation may reduce detection range. IR sensors are excellent for searching for surface ships as the heat they emit makes them stand out clearly from the cold of the ocean; for the same reason, IR sensors are also able to detect snorkelling submarines at long range.

Laser: Laser sensors are not used to search for contacts (although a laser-warning receiver [LWR] can detect the presence of laser energy), but they are very useful for determining the precise range to a contact detected by other sensors, or designating (also known as 'painting') targets for laser-guided weapons.

Your patrol boat is equipped with LLTV and IR cameras and a laser range-finder. Your helicopter is also equipped with FLIR, CCD/LLTV and a laser ranger/designator, while your RHIBs are equipped with NVGs.

Now, we'll close in with the helicopter to identify the detected contact. Set a course for your helicopter towards the detected contact (F3), and set the altitude (F2) to 2,000ft and the speed to Cruise.