Problem 1

A RADAR transmitting $100\ \text{kW}$ of power at $350\ \text{MHz}$ receives a return from a plane with an RCS of $100\ \text{m}^2$ after $250\ \mu s$. How far away is the plane?

Problem 2

An F-15 has enough fuel to travel $100\ \text{km}$. The F-15 is receiving a signal from a TACAN located on the airfield. It takes $500\ \mu s$ for the TACAN signal to travel to the F-15. Does the pilot need to hit a tanker, or does it have enough fuel to reach the runway?

Problem 3

A fighter has an RCS of $20\ \text{m}^2$. Will a fire-control RADAR that operates at $1\ \text{GHz}$, has a transmit power of $50\ \text{kW}$, and a gain of $50$ be able to lock onto the fighter if the range is $50\ \text{km}$ (and LOS is established)? To lock-on, the received power must be at least $10\ \text{pW}$.

Problem 4

The RCS of a fighter is approximately $20\ \text{m}^2$. The RCS of a missile is approximately $0.2\ \text{m}^2$. How many times farther away can the fighter be detected than the missile?

Problem 5

During an exercise, a UAS is used to gather information on red forces. The red team has deployed a mobile RADAR unit with the following parameters: | Mobile RADAR Unit | UAS | |------------------|-----| | $f = 450\ \text{MHz}$ | $\sigma = 0.4\ \text{m}^2$ | | $P_T = 1.5\ \text{kW}$ | $G_R = 3$ | | $G = 200$ | $P_{R,\min} = 1.25\ \mu\text{W}$ | | $P_{R,\min} = 1\ \text{fW}$ | | Answer the following: (a) If the RADAR signal takes $133.3\ \mu s$ to return, how far away is the UAS? (b) How much power is received by the RADAR if the UAS is $30\ \text{km}$ from the RADAR? (c) If the RADAR is located on a $45'$ hill and the UAS is ingressing at $200'$ AGL, who will see who first?