## About SpaceWorks Software

**SpaceWorks Software** develops technical and educational applications for the aerospace field and beyond. Our unique products and services are valued by government agencies, commercial companies, academic institutions, and private individuals around the world.

## Parameter Definitions

**Altitude**
- The height above mean sea level (MSL).

[ft or m]
**Ambient Pressure**
- Static pressure of the surrounding atmosphere at a given altitude. Decreases as altitude increases.

[lbs/ft^{2} or kPa]
**Calibrated Airspeed**
- Airspeed adjusted for pressure-altitude effect. Calibrated Airspeed gradually deviates from True Airspeed as altitude increases. Airspeed is typically measured using a pressure differential device called a pitot tube, and therefore is susceptible to variation at different altitudes.

[knots or m/s]
**Density**
- Ambient density value. Decreases as altitude increases.

[slugs/ft^{3} or kg/m^{3}]
**Dynamic Pressure**
- The kinetic energy of the surrounding atmosphere, introduced by the movement of an aircraft. Equal to the product of one-half the density and the square of the velocity.

[lbs/ft^{2} or kPa]
**Mach Number**
- A non-dimensional parameter equal to the velocity divided by the local speed of sound. Named after Ernst Mach.

[no units]
**Temperature**
- Ambient temperature value. Decreases with altitude through the troposphere, remains constant through the lower stratosphere, and then increases through the remainder of the stratosphere. Additional changes in slope occur at higher altitudes beyond the range of this calculator.

[°R or K]
**Velocity**
- The rate of change of distance with respect to time. In this calculator, velocity is equivalent to True Airspeed.

[ft/s or m/s]

## Version Information

Version 1.1

Released in July 2013