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Jacchia Reference Atmosphere
The Jacchia Reference Atmosphere is a reference atmospheric model that defines values for atmospheric temperature, density, pressure and other properties at altitudes from 90 to 2500 km. Unlike the more common US Standard Atmosphere and related models, the Jacchia model includes latitudinal, seasonal, geomagnetic, and solar effects, but must be supplemented with another model at lower altitudes. The model, first published in 1970 and updated in 1971 and 1977, is based on spacecraft drag data, and is primarily used in spacecraft modeling and related fields. A common assumption while using the Jacchia Model is that the atmosphere rotates with the Earth as a rigid body. The statistical accuracy of the Jacchia Model is 15%. See also *Atmospheric models *NRLMSISE-00 *International Standard Atmosphere *US Standard Atmosphere The U.S. Standard Atmosphere is a static atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Atmospheric Model
A reference atmospheric model describes how the ideal gas properties (namely: pressure, temperature, density, and molecular weight) of an atmosphere change, primarily as a function of altitude, and sometimes also as a function of latitude, day of year, etc. A static atmospheric model has a more limited domain, excluding time. A standard atmosphere is defined by the World Meteorological Organization as "a hypothetical vertical distribution of atmospheric temperature, pressure and density which, by international agreement, is roughly representative of year-round, midlatitude conditions." Typical usages are as a basis for pressure altimeter calibrations, aircraft performance calculations, aircraft and rocket design, ballistic tables, and meteorological diagrams." For example, the U.S. Standard Atmosphere derives the values for air temperature, pressure, and mass density, as a function of altitude above sea level. Other static atmospheric models may have other outputs, or depend on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Standard Atmosphere
The U.S. Standard Atmosphere is a static atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations. The model, based on an existing international standard, was first published in 1958 by the U.S. Committee on Extension to the Standard Atmosphere, and was updated in 1962, 1966, and 1976. It is largely consistent in methodology with the International Standard Atmosphere, differing mainly in the assumed temperature distribution at higher altitudes. Methodology The USSA mathematical model divides the atmosphere into layers with an assumed linear distribution of absolute temperature ''T'' against geopotential altitude ''h''.Gyatt, Graham (2006-01-14)"The Standard Atmosphere" A mathematical model of the 1976 U.S. Standard Atmosphere. The other two values (pressure ''P'' and density ''ρ'') are computed by simultaneously solving the equations resulting from: * the vertical pressure variat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Models
An atmospheric model is a mathematical model constructed around the full set of primitive dynamical equations which govern atmospheric motions. It can supplement these equations with parameterizations for turbulent diffusion, radiation, moist processes (clouds and precipitation), heat exchange, soil, vegetation, surface water, the kinematic effects of terrain, and convection. Most atmospheric models are numerical, i.e. they discretize equations of motion. They can predict microscale phenomena such as tornadoes and boundary layer eddies, sub-microscale turbulent flow over buildings, as well as synoptic and global flows. The horizontal domain of a model is either ''global'', covering the entire Earth, or ''regional'' (''limited-area''), covering only part of the Earth. The different types of models run are thermotropic, barotropic, hydrostatic, and nonhydrostatic. Some of the model types make assumptions about the atmosphere which lengthens the time steps used and increases com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NRLMSISE-00
NRLMSISE-00 is an empirical, global reference atmospheric model of the Earth from ground to space. It models the temperatures and densities of the atmosphere's components. A primary use of this model is to aid predictions of satellite orbital decay due to atmospheric drag. This model has also been used by astronomers to calculate the mass of air between telescopes and laser beams in order to assess the impact of laser guide stars on the non-lasing telescopes. Development The model, developed by Mike Picone, Alan Hedin, and Doug Drob, is based on the earlier models MSIS-86 and MSISE-90, but updated with actual satellite drag data. It also predicts anomalous oxygen. ''NRL'' stands for the US Naval Research Laboratory. MSIS stands for mass spectrometer and incoherent scatter radar, the two primary data sources for development of earlier versions of the model. ''E'' indicates that the model extends from the ground through exosphere and ''00'' is the year of release. Over the years s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Standard Atmosphere
The International Standard Atmosphere (ISA) is a static atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes or elevations. It has been established to provide a common reference for temperature and pressure and consists of tables of values at various altitudes, plus some formulas by which those values were derived. The International Organization for Standardization (ISO) publishes the ISA as an international standard, ISO 2533:1975.International Organization for Standardization, Standard Atmosphere', ISO 2533:1975, 1975. Other standards organizations, such as the International Civil Aviation Organization (ICAO) and the United States Government, publish extensions or subsets of the same atmospheric model under their own standards-making authority. Description The ISA mathematical model divides the atmosphere into layers with an assumed linear distribution of absolute temperature ''T'' against geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
