主要内容

WGS84重力模型

Implement 1984 World Geodetic System (WGS84) representation of Earth's gravity

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  • 库:

  • 航空空间 /环境 /重力

  • WGS84重力模型块

描述

TheWGS84重力模型块实现了世界大地测量系统（WGS84）的地理为中心的等值椭圆形的数学表示。块输出是特定位置的地球重力。要控制重力精度，请使用类型of gravity modelparameter.

The block icon displays the input and output units selected from the单位列表。

限制

  • The WGS84 gravity calculations are based on the assumption of a geocentric equipotential ellipsoid of revolution. Since the gravity potential is assumed to be the same everywhere on the ellipsoid, there must be a specific theoretical gravity potential that can be uniquely determined from the four independent constants defining the ellipsoid.

  • WGS84 Taylor系列模型的使用应限于低大地高度。当不需要亚质精度时，它足够在表面附近。在中等和高的大地高度下，它的准确性较差。

  • The WGS84 Close Approximation model gives results with submicrogal precision.

  • To predict and determine a satellite orbit with high accuracy, use the EGM96 through degree and order 70.

端口

输入

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Position in geodetic latitude, longitude, and altitude, specified as a three-element vector orM-by-3数组，在选定的单元中。高度必须小于20,000 m（约65,620英尺）。

Data Types:double

Julian date, specified as a scalar. The year must be after January 1, 2000 (2451545).

Dependencies

要启用此端口，请选择输入Julian date.

Data Types:double

Output

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重力in the north-east-down (NED) coordinate system.

重力Model Method Output
泰勒系列和关闭近似 Output only normal gravity (down in the NED coordinate system).
Exact 正常和切线重力（在NED坐标系中向下和向北）。

Data Types:double

Parameters

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Method to calculate gravity, specified as:

重力Model Method Output
WGS84泰勒系列和WGS84关闭近似 Output only normal gravity (down in the NED coordinate system).
WGS84精确 正常和切线重力（在NED坐标系中向下和向北）。

Programmatic Use

Block Parameter:model
类型: character vector
价值s:'WGS84 Taylor Series'|'WGS84 Close Approximation'|'WGS84 Exact'
默认:'WGS84 Taylor Series'

输入和输出单元，指定为：

单位 高度 重力
公制（MK） Meters 每秒平方的仪表
英语 脚 脚per second squared

Programmatic Use

Block Parameter:单位
类型: character vector
价值s:“公制（MK）”|'English'
默认:“公制（MK）”

  • 要排除地球重力场的大气质量，请选择此复选框。

  • 要包括地球引力场的大气质量，请清除此复选框。

Dependencies

To enable this check box, set类型of gravity modelto重力模型WGS84关闭近似或者WGS84精确.

Programmatic Use

Block Parameter:no_atmos
类型: character vector
价值s:'on'|'离开'
默认:'on'

  • 要使用地球角速度的国际天文联盟（IAU）值计算地球的速度，右提升的进动率，请选择此复选框。

  • To calculate the velocity of the Earth using the angular velocity of the standard Earth rotating at a constant angular velocity, clear this check box.

To obtain the precession rate in right ascension, the block calculates Julian centuries from Epoch J2000.0 usingMonth,天， 和Year.

Dependencies

  • To enable this check box, set类型of gravity modelto重力模型WGS84关闭近似或者WGS84精确.

  • Clearing this check box disables the输入Julian dateparameter and theJD输入端口。

Programmatic Use

Block Parameter:进动
类型: character vector
价值s:'on'|'离开'
默认:'on'

  • To specify the Julian date for the block with an input port, select this check box.

  • 使用的值计算朱利安日期Month,天， 和Year, clear this check box. The year must be after January 1, 2000 (2451545).

Dependencies

  • To enable theJDport, select this check box.

Programmatic Use

Block Parameter:jd_loc
类型: character vector
价值s:'on'|'离开'
默认:'on'

从Epoch J2000.0计算朱利安世纪的月份。

Dependencies

启用此参数：

  • Set类型of gravity modeltoWGS84关闭近似或者WGS84精确.

  • SelectPrecessing reference frame.

要禁用此参数，请选择输入Julian date.

Programmatic Use

Block Parameter:month
类型: character vector
价值s:'一月'|'二月'|'行进'|'April'|'May'|'June'|'七月'|'August'|'九月'|'October'|'十一月'|'December'
默认:'一月'

天to calculate Julian centuries from Epoch J2000.0.

Dependencies

启用此参数：

  • Set类型of gravity modeltoWGS84关闭近似或者WGS84精确.

  • SelectPrecessing reference frame.

要禁用此参数，请选择输入Julian date.

Programmatic Use

块参数：天
类型:character vector
价值s:'1'to'31'
默认:'10'

一年来计算朱利安世纪的朱利安世纪。这一年必须是2000年或更高。

Dependencies

启用此参数：

  • Set类型of gravity modeltoWGS84关闭近似或者WGS84精确.

  • SelectPrecessing reference frame.

  • 要禁用此参数，请选择输入Julian date.

Programmatic Use

块参数：一年
类型:character vector
价值s:any year
默认:'2004'

  • To base calculated gravity on pure attraction resulting from the normal gravitational potential, select this check box.

  • To enable the calculated gravity to include the centrifugal force resulting from the Earth's angular velocity, clear this check box.

此选项仅可用重力模型WGS84关闭近似或者WGS84精确.

Programmatic Use

Block Parameter:no_centrifugal
类型: character vector
价值s:'on'|'离开'
默认:'on'

Out-of-range block behavior, specified as follows.

价值 描述

没有任何

No action. The block imposes upper and lower limits on an input signal.

警告

在诊断观看器中警告，模型模拟仍在继续。对于加速器和快速加速器模式，将操作设置为警告没有效果，模型的行为似乎是设置为没有任何.

错误

MATLAB®returns an exception, model simulation stops. For Accelerator and Rapid Accelerator modes, setting the action to错误没有效果，模型的行为似乎是设置为没有任何.

Programmatic Use

Block Parameter:action
类型: character vector
价值s:'None'|'Warning'|'错误'
默认:'Warning'

参考

[1] "Department of Defense World Geodetic System 1984, Its Definition and Relationship with Local Geodetic Systems." NIMA TR8350.2.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

版本嘘或者y

在R2006a之前引入

See Also

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