ES , previously known as ES measures (ESM), is considered the eyes and ears
of the EW effort, in that ES
is responsible for the detection, processing, recording and identification of
electromagnetic energy transmitted by hostile, friendly and neutral radar systems.
The main aim of ES is to
gain sufficient information about radar sensors to allow an understanding
of the radar’s characteristics including its role, its method of
operation, and its strengths and weaknesses. With this information, the
ES system can identify the radar, assess
its relative threat and provide information to the operator on
how best to manage the radar’s presence.
Many factors impact on
the effectiveness of ES, but all factors
can be grouped into one of the following categories:
transmitter characteristics
including transmitted power, operating frequency, polarisation, signal bandwidth;
transmitting antenna characteristics
including beamwidth, sidelobe levels, and scan patterns;
environmental characteristics between the
radar and the ES equipment including atmospheric
and meteorological conditions; and
the capability of the ES equipment including the receiving antenna characteristics, and the receiver
capabilities and sensitivity.
ES is a passive activity
as the ES equipment does not transmit
any electromagnetic energy in the performance of its roles. It
is important that the adversary remains unaware of the ES
activity, because there are many tactics an adversary radar system
can employ to make the ES role
even more difficult than it is normally. Additionally, remaining passive
lessens the opportunity for the adversary radar to plant false
information into the transmissions in an attempt to corrupt or
confuse the ES effort.
Other topics in our resources on Radar related to ES include: