Codejack, on 27 January 2013 - 08:57 AM, said:
I'm not sure, but it references Total Warfare and includes experimental equipment, which tells you that it is fairly late.
It's from page 223 of
Tactical Operations, one of the four core books that make up the current BattleTech rule set.
"
Tactical Operations is the one-source reference for advanced rules that apply to on-world operations. It includes new movement and combat options, an extensive Advanced Weapons and Equipment section, and the rules for playing and constructing advanced Support Vehicles and Mobile Structures."
----------
With regard to the TAG vs ECM debate...
The description of TAG's operation from page 238 of
TechManual (one of the four core rulebooks, dealing with unit construction and equipment specifications and backstory):
"Though it built on techniques already centuries old in 2600, Grumman Industries’ Alloran In-Line target acquisition gear became the model for the artillery-spotting laser communications system today known simply by the acronym TAG.
More than a simple infrared laser-based target designation system, the TAG system tied into the user’s on-board targeting and tracking systems and used its own integral tight-beam laser communications array to link into the receptive guidance systems of certain friendly artillery warheads and guided bombs."
Contrast this with
TechManual's description of the (somewhat-similar) Artemis IV Fire Control System (on page 206):
"In an effort to enhance the accuracy and lethality of standard missile racks, the first Star League developed the Artemis IV fire-control system.
Mounted in a dome near the enhanced launcher, the Artemis was in essence an infrared laser designator, target lock mechanism and tightbeam microwave transmitter that - together with specialized missile control systems - helped to focus the spread of all missile volleys so enhanced."
The difference - and the reason why ECM affects Artemis and why it shouldn't affect TAG - is that Artemis uses a microwave-based transmission system to communicate with its missiles, while TAG uses a laser-based communication system to communicate with its missiles.
As
microwaves are ultimately radio waves (more specifically, "radio waves with wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz"), they would be generally subject to many of the same types and sources of interference as the radio waves used in radar systems (recall, the term "
radar" was originally an acronym that stood for "
RAdio
Detection
And
Ranging") and other radio-based technologies (such as Wi-Fi routers, garage door openers, and cell phones).
ECM systems are built to create a lot of "
electronic noise" across a wide or specified number of radio frequencies; with enough noise, radio-based communications - such as those upon which Artemis and its associated missiles are reliant - fail, as the receiver (in this case, the Artemis missile) receives only garbled, static-filled noise rather than useful information.
By contrast, TAG uses an open-air, laser-based communications technique called "
Free-Space Optical Communication", or "FSO", to communicate with its missiles via a laser transmitter (in the TAG unit, on the 'Mech) and receiver (on the missile) system.
Some of the primary advantages of FSO are high bit rate (the ability to transmit a lot of information quickly), low bit rate error (relatively little information is lost or transmitted with errors), and effective immunity to EM interference (such as the radio noise generated by ECM systems).
However, FSO is not without its disadvantages - mainly, interference from atmospheric effects and the possibility of solid objects (insects and birds, terrain, etc) blocking the laser beam.
----------
With regard to the OP:
The workings of ECM in MWO are largely reflective of how Guardian ECM (as distinct from Angel ECM) function in BattleTech, once the advanced combat rules found in Tactical Operations are taken into account.
I've written a number of detailed posts on the subject; they can be read
here,
here, and
here.
I've also written a rather detailed post on the relationship between the functioning of Streak missile systems and both Guardian and Angel ECM Suites in BattleTech; it can be read
here.