Solar zenith angle minutes of arc, which is less than the apparent angular radius of the sun. The formula also neglects the effect of atmospheric refraction. Sunset and sunrise occur (approximately) when the zenith angle is 90°, where the hour angle "h" satisfies Precise times of sunset and sunrise occur when the upper limb of the Sun appears, as refracted by the atmosphere, to be on the horizon. A weighted daily average zenith angle, used in computing the local albedo of the Earth, is given by where "Q" is the instantaneous insolation. For example, the solar elevation angle is : An exact calculation
Type 10 concluded that there was not enough internal space for a C4I system upgrade on existing tanks. Therefore, the development of a new main battle tank capable of various future battle missions was necessary. The use of modular components significantly improved the side armor compared to the Type 90. The Commander's Panoramic Sight was moved to the right and is located at a higher position than the Type 90, giving the commander a wide range of view. The vehicle's armor consists of modular sections, providing the ability to mount varying degrees of protection depending on the mission profile and weight requirements.