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Std. Atmosph.

Balloons

Theory

Std. Atmosph.

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Flight 2(bis)

Flight 3(bis)

Theory

Other 'ballooners'

More theory:

**Standard atm.**

Calculator

Descent spd

After searching quite a bit for practical formulae to do this job,
I finally took the excellent work of Hugo Lorente, published by
AMSAT Argentina in the proceedings of the 1er Simposio de Comunicaciones
Satelitales y Digitales (22/23 de setiembre de 1990), and derived the
ones that are below.

(Each case presents the theoretical formula, and then a version with all
constants replaced by their values).

For those who are not interested in the formulas, I've published a an on-line calculator on another page.

**OJO**: All formulas use metric units! (like hectoPascal
(hPa), g in m/s², height in meters (m), etc.

Presure > 226.3203 hPa | |

54.749 < Pressure < 226.3203 hPa | |

8.68 < Pressure < 54.749 hPa | |

Pressure < 8.68 hPa |

To complete the list, I'll include the original (inverse) formulas below:

Height < 11000m | |

11000m < Height < 20000m | |

20000m < Height < 32000m | |

32000m < Height |

Where:

- T
_{0} - Temperature at 0 m (288.15°K)
- T
_{11} - Temperature at 11000 m
- T
_{20} - Temperature at 20000 m
- T
_{32} - Temperature at 32000 m
- a
- Temperature at sea level
- b
- Temperature decrease per m altitude:
0 - 11000m -0.0065°K/m 11000 - 20000m Stable 20000 - 32000m +0.001°K/m 32000 - 47000m +0.0028°K/m

- g
- 9.80665 m/s²
- rho
_{0} - Air density at 0 m (1.225 kg/m
^{3}) - P
_{0} - Pressure at 0 m (1013.25 hPa)

(c) John Coppens ON6JC/LW3HAZ |