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The role of radar is similar to that of the eyes and ears; of course, it is no longer a masterpiece of nature； At the same time, its information carrier is radio waves. In fact, whether it is visible light or radio waves, they are essentially the same thing – both are electromagnetic waves that travel at the speed of light C in a vacuum. The difference lies in their respective frequencies and wavelengths. The principle is that the transmitter of the radar equipment sends electromagnetic wave energy in a certain direction through the antenna; objects located in that direction reflect these electromagnetic waves. The radar antenna receives these reflected waves and sends them to the receiving device for processing, so as to extract certain information about the object (such as the distance from the target object to the radar, the rate of change of distance or radial velocity, azimuth, altitude, etc.). The principle of distance measurement is to determine the time difference between the transmitted pulse and the echo pulse; since electromagnetic waves travel at the speed of light, this difference can be used to calculate the precise distance between the radar and the target. The principle behind measuring the target’s azimuth is to utilize the antenna’s narrow azimuthal beam; by measuring the elevation angle with such a narrow beam, it is possible to calculate the target’s height based on both the elevation angle and distance. The principle of speed measurement is that radar relies on the frequency Doppler effect generated by the relative motion between itself and the target. The frequency of the target echo received by the radar is different from the radar’s transmission frequency, and the difference between the two is known as the Doppler frequency. One of the main pieces of information that can be extracted from the Doppler frequency is the rate of change of the distance between the radar and the target. When the target and the interference clutter are both present within the same spatial resolution element of the radar, the radar can use the difference in their Doppler frequencies to detect and track the target amidst the interference clutter. The specific applications and structures of various radars vary, but their basic format is the same, including: a transmitter, a transmitting antenna, a receiver, a receiving antenna, a processing unit, and a display. There are also auxiliary devices such as power supply equipment, data acquisition equipment, and anti-interference equipment. There are many types of radar, and the methods of classification are also very complex. Military radars can usually be classified according to their purpose, such as early warning radars, search and surveillance radars, guidance and control radars, gunnery control radars, altimetry radars, battlefield surveillance radars, airborne radars, radio altimetry radars, radar fuses, weather radars, air traffic control radars, navigation radars, as well as collision avoidance and friend-or-foe identification radars. Classified by the form of radar signals, there are pulse radar, continuous-wave radar, pulse-compressed radar, and frequency-hopping radar, among others. Classified by angle tracking method, there are single-pulse radars, cone-scanning radars, and stealth cone-scanning radars, etc. Classified by the parameters measured according to the objectives, there are height-measuring radars, two-coordinate radars, three-coordinate radars, friend-or-foe identification radars, multi-station radars, and others. Based on the technology used in radar and the methods of signal processing, there are coherent accumulation and incoherent accumulation, moving target display, moving target detection, pulse Doppler radar, synthetic aperture radar, and side-scanning while tracking radar. Classified by antenna scanning method, they include mechanically scanned radars, phased array radars, etc. Classified by radar frequency band, they can be divided into beyond-visual-range radar, microwave radar, millimeter-wave radar, and lidar, among others. Between 19:00 and 22:00 on April 19, 2005, gravity wave structures were detected by the Harbin radar station; the velocity field data from the new generation of Doppler weather radars were primarily used to analyze the gravity wave structures associated with this phenomenon. During the development of this gravity wave, the radial velocity exhibits a pattern of alternating positive and negative values in the horizontal direction; below an average height of 1100 meters in the horizontal direction, there is an alternating pattern of upward and downward air currents, and the air currents in the vertical direction are sometimes at an angle to the vertical axis. The wavelength of the gravity wave is approximately 5 km, with a phase speed of about 10 m/s. Phased array radar, also known as phase array radar, is a type of radar that changes the direction of its beam by altering the phase of the radar waves. Since the beam is controlled electronically rather than through traditional mechanical rotation of the antenna surface, it is also referred to as electronically scanned radar. Phased array technology appeared as early as the late 1930s. In 1937, the United States was the first to begin this research work. It was not until the mid-1950s that two practical shipborne phased array radars were developed. In the 1980s, phased array radar saw further application due to its many unique advantages. Multifunctional phased array radars are widely used in the new generation of medium and long-range air defense missile systems that are already in service or under development; they have become an important feature of third-generation medium and long-range air defense missile systems. Thus, **the combat performance of the air defense missile weapon system was improved. In the 21st century, with the continuous advancement of technology and the characteristics of modern military weapons, the development and research of phased array radar will reach new heights.