Author: **Dr. Dao Chi Thanh**

Faculty: **Vietnam National University, Hanoi**

Country: **Vietnam**

e-mail: **Pqnguyen77@yahoo.com**

The radar transmits a variable elliptical polarization signals, the reflected signals from the targets are received and processed in 2 receiver channels, the output signal from the 2 receiver channels is processed by weighted, multi-dimensions special algorithms – formulas for getting the highest detection probability.

ADVANTAGE

1-This technology can detect very small tagets with the RCS small to 0.01 m2 , and the potencial even smaller than 0.01 m2;

2-Displaying only 1 color will choose a variant to get better ability to detect the target class of that color;

3-Changing the color assignment scheme will select the color assignment plan for better target detection and classification;

4-Very good background noise supression;

5-Capable of detecting targets in the woods (forest) because the Jαβ of the target is different from Jαβ of the woods;

6-Base on Jαβ we can classify and identify targets by creating a library of Target Types of Parameters Jαβ to defind target identification and classification, this is a very important issue in radar engineering.

Radar transmits an elliptical polarized signal of the form i : e i T, ( i is positive integers in the range [1 ÷ I ], I is any positive integer that takes value in the range [1 ÷ +∞ ) (1) ), the elliptic signal i reflected from the target e i R can be decomposed on the union of 2 circularly polarized signals: right circular polarization and left circular polarization having different amplitudes which are received and processed in 2 receiver channels; the output signals from receiver channels 1, receiver channel 2 are E i1 , E i2 ; E i1 , E i2 are sent to the Signal Processing System and then sent to the Digital Signal Processing System to compute:

– Iiαβ = (2) is the Weighted Ratio (WR) of E i1 , E i2 ; α, β are positive integers (in the general case will be plural) in the range [1 ÷ M], M is any positive integer that takes value in the range [1 ÷ +∞ ) (3).

– Weighted Radar Cross Section (WRCS) of the target is computed:

Ϭiαβ = Ϭiαβ ( α, β, ) (4)

– Jiαβ = Jiαβ ( Iiαβ ) (5)

Jiαβ is the coefficient reflecting the Weighted Eigenfeatures (WE) of the target.

Jiαβ will be in the range [-a, +a] (6), a is a definite positive integer, range [ -a, +a ] is divided into N segments, N is a positive integer in the range [1 ÷ 100 ) (7), each segment is assigned a color so in the range [ -a, +a ] there are N segments corresponding to N colors, each color corresponds to a target class with the same Jiαβ value. Jiαβ , Ϭiαβ will be taken to a 2-dimensional display: color type, color brightness; Jiαβ determines the color type, which is the color of the target marker; Ϭiαβ determines color brightness, which is the brightness of the target marker (8).

The number of color types N is enough to be easily distinguishable by the eye, in the case of auto-detection using Artificial Intelligence (AI) technology, the number of color types that can be selected is large enough to satisfy the target marker resolution.

For each set of values α , β we have a pair of values Jiαβ , Ϭiαβ , for each pair of Jiαβ , Ϭiαβ we have a value of PDiαβ ( Target Detection Probability ); then we will have the value PDimax = Max { P Diαβ }; α, β = [ 1,…,M] (9), so we have a pair of α , β for the PDimax for each signal type elliptic polarization ei – PD is a most important parameter of radar.

The transmitted signal is parameterized to have ellipses of the form i (i = [1…I], then we have PDmax max = Max {PDimax } (10) i= [1…I], which is the highest Detection Probability P Dhighest = P Dmax max (11).

Set of Algorithms – Formulas (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11) have implemented a weighted processing variable elliptical polarization radar signal in 5-dimensional space: α , β , Jαβ , Ϭ αβ , and time t give the highest Detection Probability. It is called “Weighted, multi-dimentional processing of variable eliptical polarization radar signal for highest Detection Probability”.

With this set of Algorithms – Formulas, we will not only choose the set of parameters α , β for the highest Detection Probability, but also base on Jαβ we can establish a library of Parameters Jαβ – Type targets to be able to identify and categorize targets. This is a very important issue in radar engineering.

In fact, we can have a very simple way of implementing the above Algorithms-Formulas: With the parameters I, M, N, α, β selected defined, the 2 important parameters Jαβ, Ϭαβ are computed while the radar continuously transmits e i T and brought them ( Jαβ, Ϭαβ ) to the display.