Difference between revisions 1813695 and 1813696 on enwikiversity

[[Image:Skylab-73-HC-440HR.jpg|thumb|right|200px|The Saturn V SA-513 lifts off to boost the Skylab Orbital Workshop into Earth orbit on March 14, 1973. Credit: NASA.]]
[[Astronomy]] is performed by location and is subject to local conditions. The shapes and sizes of observatories have changed over time, as have their altitude. The motivations for putting an observatory manned or unmanned at different altitudes has led to a great variety in '''lofting technology'''.
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As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. Although the term altitude is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the "down" direction are commonly referred to as depth.

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”'''Indicated altitude''' -- the [[w:altimeter|altimeter]] reading
*'''Absolute altitude''' -- altitude in terms of the distance above the ground directly below it
*'''True altitude''' -- altitude in terms of elevation above sea level
*'''[[w:Height|Height]]''' -- altitude in terms of the distance above a certain point
*'''[[w:Pressure altitude|Pressure altitude]]''' -- altitude in terms of the [[w:air pressure|air pressure]]
*'''[[w:Density altitude|Density altitude]]''' -- altitude in terms of the density of the air”<ref name=Altitude/>.
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==Altitude regions==
{{main|Locations/Earth/Altitudes|Altitudes}}
The [[w:Earth's atmosphere|Earth's atmosphere]] is divided into altitude regions:<ref name=NWS>{{ cite book
| title=Layers of the Atmosphere, In: ''JetStream, the National Weather Service Online Weather School''
| publisher=National Weather Service
(contracted; show full)[[Category:Astronomy learning projects/Lectures]]
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