Crate aero_atmos 

aero_atmos: an Atmospheric and Aeronautical Calculations Library

Atmospheric Models

This library provides functions and calculations based on standard atmospheric models.

Numerous atmospheric models have been published. This crate seeks to replicate the calculations contained in these models.

It is intended that this crate will support these atmospheric models:

• ICAO ISA, Doc 7488/3 (1993)
• US Standard Atmosphere (1976)
• ISO Standard Atmosphere, ISO 2533, (1975)

Aerodynamics

This library does not yet support aerodynamic calculations. In the future, the intent is to provide integration between atmospheric models and aerodynamic calculations.

Examples

Get the ISA Standard Pressure at a Given Geopotential Altitude

use aero_atmos::InternationalStandardAtmosphere;

// uom Altitude units
use uom::si::length::meter;
use uom::si::f64::Length;

// uom Pressure units
use uom::si::pressure::pascal;
use uom::si::f64::Pressure;

// Create a new uom Length representing 16,000 meters of Geopotential Altitude. 
// Any input unit can be used, so long as it is within the range -5 to 80 km.
let altitude = uom::si::f64::Length::new::<uom::si::length::meter>(16_000.0);

// Calculate the ISA standard pressure at the given geopotential altitude.
let pressure = InternationalStandardAtmosphere::altitude_to_pressure(altitude);

match pressure {
    // prints ~ "p = 101325.0 Pa"
    Ok(p) => println!("p = {} Pa", p.get::<uom::si::pressure::pascal>()),
    // should not print an error message, since the altitude is within the valid range for the ISA model
    Err(e) => println!("Error calculating pressure: {:?}", e),
}

Convert between Geopotential and Geometric Altitudes

The ISA uses an appoximation formula to convert between geopotential and geometric altitudes.

use aero_atmos::InternationalStandardAtmosphere;

// Altitude units
use uom::si::length::{meter, foot};
use uom::si::f64::Length;

// Create a new uom Length representing 10,000 feet of Geometric Altitude.
let geometric_altitude = Length::new::<foot>(10_000.0);

// Convert to Geopotential Altitude.
// This example shocases the `uom` crate's ability to handle multiple units.
let geopotential_altitude = InternationalStandardAtmosphere::altitude_geometric_to_geopotential(geometric_altitude);

match geopotential_altitude {
    Ok(alt) => {
        // prints something like "Geopotential Altitude at 10,000 feet Geometric: 9995.0 feet"
        println!("Geopotential Altitude at 10,000 feet Geometric: {} feet", alt.get::<foot>());
    },
    Err(e) => println!("Error converting altitude: {:?}", e),
}

Get the Geometric altitude for a given pressure.

use aero_atmos::InternationalStandardAtmosphere;
use aero_atmos::dbg_sci;

// Altitude units
use uom::si::length::{meter, foot};
use uom::si::f64::Length;

// Pressure units
use uom::si::pressure::pascal;
use uom::si::f64::Pressure;

// Create a new uom Pressure representing 50,000 Pa.
let pressure = Pressure::new::<pascal>(50_000.0);

// First, we calculate the Geopotential Altitude for the given pressure.
// In Doc 7488/3 Table 7, 50_000 pa is about 5_574.0 meters.
let geopotential_altitude = InternationalStandardAtmosphere::altitude_from_pressure(pressure).unwrap();
dbg_sci!(geopotential_altitude.get::<meter>(), 4);
// prints something like "[src/main.rs:31] geopotential_altitude.get::<meter>() = 5.5744e3"

// Then, we convert the Geopotential Altitude to Geometric Altitude.
let geometric_altitude = InternationalStandardAtmosphere::altitude_geopotential_to_geometric(geopotential_altitude).unwrap();
dbg_sci!(geometric_altitude.get::<meter>(), 4);
// prints something like "[src/main.rs:36] geometric_altitude.get::<meter>() = 5.5793e3"

Re-exports

pub use icao_standard_atmos::InternationalStandardAtmosphere;

Modules

icao_standard_atmos

The International Standard Atmosphere (ISA) module.

macros

This macros module contains custom macros used primarily for testing.

Macros

assert_eq_precision

Macro that checks whether two numerical values are approximately equal within a specified precision. Used in tests.

assert_eq_sigfigs

Assert numbers rounded to a specified number of significant figures are equal. Used in tests.

dbg_sci

Debug macro for numerical values in scientific notation

Constants

PRECISION

Precision constant for testing. 0.05%.