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Google Earth is a computer program that renders a 3D representation of Earth based primarily on satellite imagery. The program maps the Earth by superimposing satellite images, aerial photography, and GIS data onto a 3D globe, allowing users to see cities and landscapes from various angles. Users can explore the globe by entering addresses and ...
Subsolar point. The subsolar point on a planet is the point at which its Sun is perceived to be directly overhead (at the zenith); [1] that is, where the Sun's rays strike the planet exactly perpendicular to its surface. It can also mean the point closest to the Sun on an astronomical object, even though the Sun might not be visible.
Zenith. The zenith (UK: / ˈzɛnɪθ /, US: / ˈziːnɪθ /) [1] is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere.
Lahaina Noon. Lāhainā Noon, also known as a zero shadow day, is a semi-annual tropical solar phenomenon when the Sun culminates at the zenith at solar noon, passing directly overhead (above the subsolar point). [1] As a result, the sun's rays will fall exactly vertical relative to an object on the ground and cast no observable shadow. [2]
Viewing frustum. v. t. e. A bird's-eye view is an elevated view of an object or location from a very steep viewing angle, creating a perspective as if the observer were a bird in flight looking downward. Bird's-eye views can be an aerial photograph, but also a drawing, and are often used in the making of blueprints, floor plans and maps.
A satellite ground track may be thought of as a path along the Earth's surface that traces the movement of an imaginary line between the satellite and the center of the Earth. In other words, the ground track is the set of points at which the satellite will pass directly overhead, or cross the zenith, in the frame of reference of a ground observer.
Analemma on Earth as the position of the Sun is directly overhead every 24 hours over one year. An analemma can be traced by plotting the position of the Sun as viewed from a fixed position on Earth at the same clock time every day for an entire year, or by plotting a graph of the Sun's declination against the equation of time.
An observer standing on Earth's equator visualizes the celestial equator as a semicircle passing through the zenith, the point directly overhead. As the observer moves north (or south), the celestial equator tilts towards the opposite horizon. The celestial equator is defined to be infinitely distant (since it is on the celestial sphere); thus ...