Electronic Countermeasures – F-14 Avionics – Part II

DCS and Electronic Countermeasures: Table of Contents

Unfortunately, none of the several controls related to this topic and available to the real-life Radar Intercept Officer are implemented in DCS, due to the extremely simplistic implementation of jamming mechanics in this game. However, a capable RIO can still offset, if not straight take advantage, of the interesting new features introduced in Patch 2.8.

The Issue: Determining Range

Since jammers in DCS are noise-jamming devices that deny the range, but not angles, one of the parameters necessary to launch a missile is missing. Moreover, without range, even assessing the geometry becomes a complex task, as tracks cannot be created. However, a capable RIO can still put together the clues provided by the many systems at his disposal.

Television Camera Set

The TCS can spot targets at considerable distances. It is also capable of pointing the radar on the contact, depending on how the RIO has configured it.
One of the drawbacks of the TCS in DCS is the game engine rendering distance, which has a flat cutoff of ~42nm: beyond this value, the game engine will not show the contact. When the threshold is crossed, the target suddenly appear, smoke and everything. This prevents the RIO from assessing the distance at long range.

A possible, rough, solution, is using the cutoff rendering distance to determine whether the target is within 40nm. If that is the case, it can be threatened, geometry allowing, with a manually lofted AIM-54. More on this later.

LINK4C: Underrated, Ultrauseful

Up to this point, LINK4C was very rarely used by the vast majority of players, and it is vastly underrated. Instead, it is a useful tool in a few situations, these are two common examples:

• INS Fix Update: multiple F-14s can update their INS fix from a donor F-14. The process is rapid, and saves time, on top of limiting potential issues. The “buddy INS”, as I dubbed it, requires LINK4C and, optionally, radar lock, to account for the different position of the receiving aircraft. More information here;
• LINK4A limitations: every F-14 crew know how 4A is a terribly limited datalink mode in complex situations. When civilian assets are in the scenario, the AI AWACS goes nuts and sends all sorts of pointless information. For this reason, switching the Section to 4C allows decluttering the picture, focusing only on a limited number of Groups.

The application of LINK4C to Jamming is very interesting. Since the F-14 can angle-track a jamming aircraft, having two F-14s sharing information and separated by a meaningful distance, allow them to triangulate the distance of the jamming aircraft.

When flying in a multiplayer server LINK 4C may not work, unless the aircraft spawned are part of the same group. This means that, very often, you won’t be able to take advantage of its capabilities in casual servers.

LINK4A

An AWACS such as the E-2 or the E-3 is capable of seeing through most jamming. In DCS, this means that the jamming contact is perfectly visible on the TID, but it cannot be used by the WCS to compute a valid firing solution. Thus, it does not affect directly the employment of the missiles
Considering how common AWACS are in servers, this is the simplest solution to solve the issue of the lack of range information.

Jamming Effects on the Displays

Patch 2.8 added the Automatic Gain Control (AGC) trace to the DDD, showing the strength of the radar returns.

Available in Pulse Doppler mode, in case a jamming aircraft is encountered, a Jet spike is clearly shown on the display.
Unfortunately, the trace is not very precise, and assessing the drift is not simple at great ranges but, if the jammer is just above burnthrough range, it can be assessed when consistent.

In the image above, three points are marked:

• The first point is a normal return on the DDD in PD Mode. Its “mark” on the AGC trace is the lower spike on the left (~4L ATA).
• Point #2 and point #3 are two jamming targets, easily identifiable by the vertical line in the middle of the AGC cusp (JET – Jam Exceeds Threshold).

When a jammer appears in Pulse radar mode instead, a “line” drawn at the correspondent ATA appears through the DDD. This represents the lack of information pertaining to the range.
The example shown in the figure below is the same previously discussed. The most notable difference is the appearance: since the ambiguity is in the range, a vertical line is drawn at the correspondent angle, rather than marked over the AGC trace.

• Point #1 shows the single, normal, return;
• Point #2 and point #3 show two jamming targets.

The scale of the DDD is 100nm.

On the Tactical Information Display, jamming aircraft are marked by a line starting from the F-14’s position, and pointing towards the angle the jamming is originating from.

If the TID becomes too cluttered, JAT SYMBOL function removes such symbology immediately. Similarly to datalinked contacts, toggling this function for better visibility helps in crowded scenarios.

The scenario shown on the TID in the Figure above features two jamming aircraft and a non-jamming aircraft.
The figure below adds more details:

1. “clear” radar contact; the non-jamming aircraft;
2. datalinked track from an AWACS via LINK4A;
3. jamming aircraft trace, note that the track via LINK4A is clearly visible;
4. the angular bracket is displayed at the fixed distance of 50nm along the jamming vector originating from the F-14;
5. second jamming contact, located at a range of 50nm;
6. radar boundaries.

Burning Through

When the jamming aircraft are closer than the burnthrough range, the radar “overcomes” the target’s ECM, and contacts become visible.
This phenomenon was discussed in the previous Chapter. Note that different aircraft have different burnthrough ranges, arbitrarily determined by ED. Some examples are shown in Part III of this series.

The DDD depicted in the figure above shows how, past the burnthrough range, returns are displayed clearly. Nevertheless, the AGC trace still shows a spike and the JET line matching the angle of the targets.

The TID haves similarly, representing the lines pointing towards the jamming targets, but also the radar returns.

In Pulse mode, the matter is slightly more complicated, as the vertical noise trace is always displayed. However, by playing with Pulse Video, Gain and Erase, a slightly thicker brick may be noticed, and its position is further highlighted in supersearch mode.
Figure 242 shows the DDD in Pulse mode with the HCU cursor is supersearch mode on the left, and on the right a successful PSTT lock.
The operation becomes much simpler if the range is known or can be estimated, allowing for a more precise bracketing in supersearch mode.

Seeing Beyond the Beyond Visual Range

Besides marking the ATA of the jammer, the AGC trace in PD mode provides a means to further improve the SA of the Radar Intercept Officer. For example, the show appears even farther than a solid return in PD SRCH. Therefore, the RIO can start building awareness even at 130+ nm versus fighters, by using the same considerations made pre-patch 2.8 when a contact appeared in PD SRCH but not in RWS/TWS.
Previously, in fact, a RIO could establish the range of a target depending on how the target appeared on the DDD and TID. If the target appeared only in PD SRCH, a fighter-sized target may have been between 90 nm and 110 nm. Now, an additional step can be added, depending on the appearance of the AGC trace without a PD SRCH brick. Since angles and altitude can be approximated in any radar mode (speed requires at least PD SRCH), a RIO can start building SA at incredible range, easily outranging the AWACS present in DCS.

The trace also allows the RIO to monitor targets hiding into the two blind spots of Pulse Doppler mode: notching and zero Doppler.

The figure above shows a return fading as the target entered the lower boundary of the Mainlobe Clutter filter region, but the AGC trace is still solid.
The “ghost” of the AGC also allows determining the drift slightly more clearly than the return itself. In cases such as the one discussed, it allows the RIO to track the target directly. In conjunction with the EL Indicator, changes in elevation can be monitored as well.

Video!

Most of the concepts discussed in this video are shown in the following brief video:

Part III will move to the usage of AIM-54 Phoenix and AIM-7 Sparrow in an ECM-heavy environment.
Unfortunately, this will show even more how exploitable and predictable the AI in DCS is.