What is the function of STC control?
Sensitivity time control (STC), also known as swept-gain control, is a system used to attenuate the very strong signals returned from nearby ground clutter targets in the first few range gates of a radar receiver. Without this attenuation, the receiver would routinely saturate due to the strong signals.
What are the functions of AGC in tracking radar?
The AGC circuit keeps the receiver’s output level from fluctuating too much by detecting the overall strength of the signal and automatically adjusting the gain of the receiver to maintain the output level within an acceptable range.
What is radar sensitivity?
The receiver sensitivity measurement determines the lowest possible power (MDS, Minimum Detectable Signal, or Minimum Discernible Signal) at the input of a receiver with which the radar can still detect a target. This measurement provides an important indication of the performance of a radar.
What is the use of the receiver unit features STC and FTC?
The STC and FTC are commonly used to some clutter. The radar signal is widely used for weather forecast, air port traffic control, military and fire control. The system implements radar processing procedures in real time mode in FPGA (field programmable gate array).
What does STC mean in radar?
In this article, we discuss the issue of STC. “STC” stands for Sensitivity Time Control. This is really a radar system term. Most modern radar systems have a need to attenuate, in a controlled way, the amplitude of large target returns that may occur close to the trailing edge of the transmitted pulse.
What is FTC in radar?
FTC (Fast Time Constant) – With FTC in operation, only the leading edge of an echo of a long-time duration is displayed on the radar scope. FTC tends to reduce the saturation of the scope by clutter. Also called Anti-Clutter or Differentiator.
Why is AGC used?
AGC is a system that controls the increase in the amplitude of an electrical signal from the original input to the amplified output, automatically. AGC is used in data processing to improve the visibility of seismic data in which attenuation or spherical divergence has caused amplitude decay (Figure 5.3).
What are the advantages of AGC?
The most important advantage of AGC is that it is very fast to apply and does not require complicated processing parameters to be selected accurately. However, it also has a very substantial disadvantage: it completely removes relative amplitude information embedded in the seismic data.
What is sensitivity in RF?
Editorial Team – everything RF Receiver sensitivity is a measure of the minimum signal strength that a receiver can detect. It tells us the weakest signal that a receiver will be able to identify and process. Receiver sensitivity is expressed in dBm.
What are the five 5 basic components of a radar?
five main components associated with ground penetrating radar systems are the transmitter, antenna, receiver, signal processing and display components. Figure 1 shows the radar components in a general imaging configuration consisting of layers of earth material of nominally unknown depth.
Why do we reduce radar sensitivity at short range?
This loss is called relative attenuation of the transmitter system. If the transmission power is less, the radar may not paint targets at longer range. If receiver sensitivity is less, radar may paint the targets with weak echo on the screen.
What is Second time Around echo?
Second time around echoes are returns from a target at a range greater than the range of the radar at the pulse repetition frequency in use. Second time around echoes appear as false targets in that their indicated range is about half the distance to the target, dependent on the pulse width used.
What is relation between PRF and PRT?
PRT is also equal to the sum, PRT = PW+RT. PRF = pulse repetition frequency. PRF has units of time-1 and is commonly expressed in Hz (1 Hz = 1/s) or as pulses per second (pps). PRF is the number of pulses transmitted per second and is equal to the inverse of PRT.
What is heading marker in radar?
The heading marker changes its direction according to the ship’s heading. If the TRUE motion is used, own ship and other moving targets move according to their course and speed. Fixed targets such as landmasses appear as stationary echoes.
What is AGC and its types?
There are two types of AGC circuits: i. Simple AGC: the gain control mechanism is active for high as well as low value of carrier voltage. ii. Delayed AGC: AGC bias is not applied to the amplifiers until signal strength crosses a predetermined level, after which AGC bias is applied.
What is AGC and AFC?
The receiver operates in conjunction with the automatic gain control (AGC) and the automatic frequency control (AFC). The AGC improves the dynamic range of the receiver by maintaining a constant signal level at the input of the ADCs. The AFC improves the receiver sensitivity by producing precise baseband demodulation.
What is selectivity and sensitivity?
Sensitivity refers to a radar detector’s ability to pick up police signals at the greatest distance. Selectivity refers to the detector’s ability to filter out signals that are not true police signals, yet operate on the same frequencies as police radar (i.e. security alarms, garage doors, automatic doors, etc.).