Correction, the AKG does indeed have a ballistic trajectory (not throughout its flight profile) rather than a cruise profile (it might sustain a level cruise after having attained a certain altitude but that will NOT impart any benefit as such, CMs are not dangerous because they cruise- they are dangerous when they cruise at an altitude that puts them within the radar clutter zone). In fact if you check the official releases on the system in the previous thread you will clearly find that it attains a very high altitude after launch- follows a trajectory and dives into the target. Secondly, the maneuvering is no issue at all, the interceptor vehicle its up against has a lateral acceleration of 80g- wrap your mind around that. A head on intercept does not require the interceptor to have a greater velocity than the inbound.
No, AKG doesn't have a ballistic trajectory. This is a ballistic trajectory:
A cruise missile generally follow this trajectory:
The missile has to make a compromise between four. Its weight, its range, its speed and altitude. If you want it light and long, you have to keep it slow and high. If you go for terrain hugging mode, you are bleeding energy fast. If you make it fast, than again its bleeding energy. Even BrahMos has high altitude for cruise phase:
BRAHMOS Supersonic Cruise Missile - BrahMos.com
Its cruising altitude could be up to 15 km and terminal altitude is as low as 10 meters.
The altitude is kept high for as long as possible.
Second, manoeuvring is an issue, cause how much the lateral acceleration can a interceptor have is not the only limiting factor. There is a delay of sensing, electronics, computation of new trajectory, and also, every maneuver reduces the already limited range of the interceptor. For a mach 4 interceptor vs mach .8 missile, 150 m would be covered in almost 0.1 seconds. Any change the incoming missile make would leave very little time for interceptor to adjust.
About the 80 g acceleration. Circular acceleration is v^2/r. It means for same radius circle, a mach 4 missile would have to have 25 times higher acceleration (g) than a mach 0.8 missile. That is, if a mach .8 missile makes a 10 g turn, the interceptor would have to have many times higher acceleration to keep up.
Let me clear this up. The reason a CM is more dangerous, the reason that all countries have resorted to CMs even if they be subsonic (usually with its terminal phase being supersonic) is that the low cruise profile brings it below the radar horizon (exploiting the radar clutter zone) ergo even the best systems from the MF-STAR to the SPY-2 can only detect such a threat 30-40km away. CM detection and interception (specially for high speed CMs) requires an AEW&C detecting the inbound further out and then providing a firing solution to the SAM. The same is not the case with the AKG, its high altitude flight profile makes it rather easy to detect, in fact all the way out to its launch point which falls within the MF-STAR's expressly stated detection range for high altitude ac/inbounds. Whether it changes course or maneuvers, the requirement is to actively illuminate the target with a missile fire-control director throughout the flight- and high lateral acceleration on the interceptor vehicle.
CM vs BM is debatable. What CM achieves with terrain hugging, BM does with sheer speed. The difficulty lies with CM is its detection which, as you mentioned, is solved by AEW&C. BM, you know its coming, and you just watch it hit you. If you think speed doesn't pose a problem, why would anti-ballistic systems would be such a difficult task? Ballistic missiles have a very simple and predictable path. Once you know the initial trajectory, you can predict entire flight path. Problem lies with their speed.
To what extent is AKG capable of changing it's course?
Is it capable of evasive maneuvers like the "S-Curve" done by BrahMos?
This aspect is redundant in case of AKG because the launch platform itself would be
seen by ship-borne AESAs like MF-STAR out to 400km. When the missile comes within
range, the SAMs will infact be waiting for it.
Therefore there is no question of reaction time.
Secondly, AKG appears to be subsonic for most of it's flight profile and attains high-supersonic
speeds only in terminal stage. That gives us more time in the cruise stage.
The selling point of BrahMos is its speed. And there is not much know about AKG, so all we can make are hypothesis.