this can be solved by placing the required electronics on the missile, but doing so using 1950s technology would lead to very large size and make the missile cost very high. Centralizing this at the launcher site is a much more tractable problem, especially after the introduction of military-grade transistors in the later 1950s. This led to the US Navy's RIM-50 Typhon missile and associated AN/SPG-59 radar, which had a single PESA radar and could salvo many missiles. Development problems led to its cancellation. One additional advantage of TVM is that, as there is no tracking radar, there is nothing to indicate to the target that it is being tracked. This is normally a relatively simple task for a radar warning receiver that gives the target a warning that it should employ countermeasures, but in the TVM case the search radar signal is all that is needed and it does not change when the missile is launched. Advantages Unlike an active radar homing missile, the missile does not alert the target to the fact that it is homing in on it by illuminating it with radio waves. Typically, the target will be aware that it is being illuminated by the SAM radar, but it will not know for certain if it has been engaged. Modern phased-array radars, by virtue of their thin beams and low sidelobes make detection by the aircraft even more difficult. Unlike semi-active radar homing missiles, the electronics needed to calculate and follow an interception path do not need to be built into each missile, reducing their complexity, weight and cost. It is also possible to make the missiles more accurate by using more sophisticated algorithms for calculating interception than would be possible in the limited processor in a missile. In addition, it is possible for operators to adjust the missile's flight path throughout the engagement, even during the terminal homing phase. Unlike radio command guided missiles, because the missile's radar receiver is much closer to the target than the ground station, more accurate tracking information can be generated for the system's computer. It is also more difficult to jam or spoof the tracking signal. It is also possible for the ground station to receive direct radar reflections from the target (rather than the data downloaded by the missile) and combine the two sources of information to generate the interception course. This adds an extra element of