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SAR satellites orbit in a sun-synchronous manner, meaning they pass over the same regions at the same time each day. This ensures consistent lighting for SAR images, which helps with further processing. The orbit is near-polar and can be categorized into ascending and descending tracks. Ascending track goes from the south pole to the north pole, with the LOS left-side direction towards the right side. Descending track goes from the north pole to the south pole, with the LOS direction towards the left side. The orbit of SAR satellites is decided to be sun-synchronous. Sun-synchronous orbit means that the orbit can pass through the same regions at the same mean solar time. Every time the satellite passes over the region, the sun is at the same elevation angle. In other words, the SAR images are occurred under the same illumination of the sun. Sun-synchronous orbit is useful for further processing because the consistent lighting causes similar surface properties. The sun-synchronous orbit is a near-polar orbit. So, we can further categorize it into two tracks, ascending and descending tracks. The ascending track means satellites travel from the south pole to the north pole. Since SAR satellite is a right-side-looking system, the LOS left-side direction is towards the right side. In contrast, the descending track means satellites travel from the north pole to the south pole. The LOS direction is towards the left side.