# Motion Modeling and Coordinate Systems

The Phased Array System Toolbox™ lets you model the motion of radars, sonars, targets,
jammers, or interference sources using the `phased.Platform`

System object™. This System object provides constant velocity and constant acceleration
motion models. These motion models can generate almost any type of
trajectory. You can display a 3-D visualization of a radar scenario
using the `phased.ScenarioViewer`

System object. The toolbox contains several utility functions that let
you transform between coordinates systems, transform between angular
coordinates, and convert between velocity and Doppler shift.

## Objects

`phased.Platform` | Model platform motion |

`phased.ScenarioViewer` | Display motion of radars and targets |

## Blocks

Motion Platform | Motion platform |

## Functions

## Topics

### Motion Modeling

**Doppler Shift and Pulse-Doppler Processing**

Compute target motion using Doppler processing.**Motion Modeling in Phased Array Systems**

A critical component in phased array system applications is the ability to model motion in space.**Model Motion of Circling Airplane**

Start with an airplane moving along a circular track with a radius of 10 km at a horizontal speed of 100 m/s and descending at a rate of 1 m/sec.

### Coordinate Systems

**Global and Local Coordinate Systems**

Learn about the local and global coordinate systems used in the toolbox.**Global and Local Coordinate Systems Radar Example**

This example shows how several different coordinate systems come into play when modeling a typical radar scenario.**Rectangular Coordinates**

Construct a rectangular, or Cartesian, coordinate system for three-dimensional space by specifying three mutually orthogonal coordinate axes.**Spherical Coordinates**

Spherical coordinates describe a vector or point in space with a distance and two angles.**Standards and Conventions**

This section introduces the concept of baseband signals and defines the local and global coordinate systems used in the toolbox.**Units of Measure and Physical Constants**

Phased Array System Toolbox uses the International System of Units (SI).