Taiwan, facing the prospect of an overwhelming Chinese surprise attack, is finally upgrading its SEAD (Suppression of Enemy Air Defenses) capabilities. This includes purchasing the most modern HARM (High Speed Anti-Radiation) missile the U.S. has available for export; the AGM-88E. Taiwan is getting the latest upgrades for these missiles, meaning the AGM-88Es won’t arrive until late 2022. Taiwan also has some of its F-16s upgraded, to the latest F-16V version, that includes the ability to use the AGM-88E. Taiwan is in the process of upgrading all its F-16s to this F-16V Block 52 standard.
The one missing element to the Taiwanese SEAD upgrade is intel on Chinese search and air defense radars along the nearby coast. For decades American ELINT (Electronic Intelligence) aircraft flew along the Chinese coast, outside of Chinese air space but close enough to be detected by Chinese radars and have those radar signals recorded and analyzed to determine what they were being used for. This is a key element of SEAD and it's only in the last few years that newly developed Chinese ELINT aircraft have been operating off the coasts of Taiwan, South Korea and Japan.
SEAD development is also tied with efforts, since the late 1990s, to keep American recon aircraft away from Chinese coastal areas. This was to prevent these aircraft from detecting and recording activity by Chinese air defense systems and other military electronics. Carefully analyzing these systems from a distance (international waters are anything at least 22 kilometers from the coast) reveals vulnerabilities that the U.S. could exploit in wartime. This is doubly troubling to the Chinese because the Americans are known to share this kind of information with their allies, especially Taiwan, South Korea and Japan. All this Chinese ELINT activity is now contributing to improving their new SEAD aircraft as well.
China is building more ELINT ships and aircraft and these are always nearby when American naval forces hold training exercises, especially if it is done with American allies equipped with American and other Western equipment. This has always been the case when the U.S. comes to the training even with their own AGM-88 HARM. These come in various models, giving foreign users lots of options. Some export customers still buy the older AGM-88Bs but China is most concerned with the recent AGM-88E and AARGM models which Australia recently bought.
One reason the E model is so popular is that it is capable of going after moving ships. This makes the AGM-88E an effective anti-ship weapon as well. China is very keen to find out how well this works in practice.
The AGM-88F, the first version with anti-ship capability, completed testing in 2014 and entered service. There had been so many new features in the F model that eventually the 88F got a new name; AARGM (Advanced Anti-Radiation Guided Missile) instead of a HARM. The older AGM-88s can easily be upgraded by simply replacing older sensors and guidance system components with new ones.
The AGM-88F has a GPS guidance (with less accurate but jam-proof INS as a backup) added. The older AGM-88D also used GPS so that the missile, which normally homes in on radar transmissions, could be used to attack targets by location alone. The F model expands on basic GPS capabilities and also includes other features that assist in defeating enemy electronic defenses. What the GPS/INS provides is a way for HARM to act on previous intelligence (about where an enemy radar is) while also using its radar signal homing capability and new anti-decoy features. Many countries now use a decoy emitter that sends out a fake radar signal to lure the HARM away from the real radar. The 88F model uses GPS and more sensors and new software to get around all known deceptions and some that haven’t been invented yet.
The first 88E production models were delivered in 2010 for testing on existing aircraft like the EA-18G, which entered service in 2011. AGM-88E testing ran into many problems in the three years before it entered service and there were more hardware failures than expected. The manufacturer admits that it is still working on some of these issues, but in its current state the AGM-88E is good to go.
The AGM-88 moves at high speed (2,200 kilometers an hour or 36 kilometers a minute). Over 24,000 AGM-88s, of all types, have been produced since the 1980s. AARGM weighs 361 kg (794 pounds) and can detect and attack targets more than 150 kilometers away while travelling at a speed of 2,450 kilometers per hour.
The AGM-88E can transmit a picture of the target, just before it is hit, so the user can be certain of what was taken out. The AARGM was developed jointly by U.S. and Italian firms. The original 1960s anti-radiation missile (ARM) quickly evolved into the HARM. Currently, there are orders for over 2,000 AGM-88E/Fs from the U.S. Navy and Marine Corps, Italy, and Germany.
The United States developed and began using anti-radiation missiles in the mid-1960s. The AGM-88 HARM entered service in 1985 as the AGM-88B and used passive radar seeker which home on enemy fire-control radars emissions in order to destroy it and thus render Surface-to-air missile (SAM) systems useless, least of all those which use radars for target tracking. In 1999 (Kosovo War) HARM was found to be vulnerable. The Serbian forces limited their radar usage to a minimum and used quick radar shutdown techniques and “pack and leave” tactic for their SAM units. Because of these HARM had problems with acquiring targets because the missile has precision guidance only when enemy radar is working during all the time. In “offline mode” HARM used INS/GPS only. As a result, NATO forces failed to silence Serbian SAMs during the campaign. The problem has since been solved.
China is apparently hoping to steal the new U.S. ARM technology and incorporate it into their various HARM missiles which must eventually be tested at sea to ensure that the anti-ship versions are working properly. If you know more about enemy HARM tech these systems are a lot less effective. This is especially true if you can keep secret how much you know. This the importance of ELINT, especially off the coast of foreign adversaries. That information also helps if you are developing a Chinese SEAD. That works both ways and one thing you need to keep to yourselves is how much you know about enemy radars and how much they know about yours. Who is ahead in this area won’t be known unless China attacks Taiwan.