Open-source standard atmosphere models
Calculate the Standard Atmosphere
Atmospheris provides open-source implementations of ISO atmospheric reference standards — from the baseline ISA (ISO 2533) to observed reference atmospheres, wind distributions, and humidity models (ISO 5878) — with interactive calculators, a Ruby gem, and a TypeScript library.
Quick Calculator
TroposphereStandards
ISO 2533
Standard Atmosphere
The International Standard Atmosphere — a reference model defining temperature, pressure, density, and derived properties from −5 km to 80 km altitude.
Explore ISO 2533 →ISO 5878
Reference Atmospheres for Aerospace Use
Observed atmospheric conditions by latitude zone and season — temperature profiles, wind distributions (Rice model), and humidity data for real-world aerospace applications.
Explore ISO 5878 →Features
Altitude to Properties
Calculate all 19 atmospheric properties at any altitude from -2,000 m to 80,000 m geopotential.
Try it →Pressure to Altitude
Reverse lookup: find the altitude corresponding to any atmospheric pressure value.
Try it →Wind Distributions
Compute scalar mean wind speed and percentile speeds from observed vector components using the Rice distribution (ISO 5878).
Calculator →Dual Precision
Normal precision for engineering or reduced precision for quick estimates, dynamically calculated per ISO 2533 formulas.
Learn more →Data Export
Export calculated properties to YAML, XML, and other formats for integration with your tools.
View API →Dynamically Calculated Tables
Generate custom atmospheric property tables at any step size and altitude range, dynamically computed per the standard.
See constants →Get Started
TypeScript / JavaScript
Install via npm and calculate atmospheric properties and wind distributions in just a few lines.
import { getAllProperties, computeWindDerived } from "atmospheris"
// Get all properties at 10,000 m geopotential altitude
const result = getAllProperties({
value: 10000,
unit: "meters",
type: "geopotential",
precision: "normal"
})
console.log(result.temperature.celsius) // -49.898 °C
console.log(result.pressure.mbar) // 264.36 mbar
// Wind distribution per ISO 5878
const wind = computeWindDerived(-3.9, -1.2, 5.9)
console.log(wind.Vsc) // 6.03 m/s — scalar mean wind speedRuby
The reference implementation — a comprehensive Ruby gem for ISA calculations and wind modeling.
require "atmospheris"
# Calculate properties at 10,000 m geopotential altitude
result = Atmospheris::Export::AltitudeAttrs.new
result.set_geopotential_altitude(10_000, :meters)
result.realize_values!
puts result.temperature_celsius #=> -50.0 °C
puts result.pressure_mbar #=> 264.36 mbar
# Wind distribution per ISO 5878
wind = Atmospheris::Iso5878.compute_wind_derived(-3.9, -1.2, 5.9)
puts wind.vsc #=> 6.03 m/s