## 5.1.3 positions

### 5.1.3.1 What is this node for?

This node is for representing a set of positions.

### 5.1.3.2 Attributes

- type
Mandatory. This attribute is used to specify the kind of positions.

noise: Noise position

microphone: Microphone positions

source: Localized sound source positions

tsp: Positions of TSP recording files

impulse: Positions of impulse response files

- coordinate
Mandatory. This represents the positionâ€™s coordinate system. The value must be `cartesian` for Cartesian coordinate, or `polar` for Polar coordinate

- frame
Optional. This value is used when the positions node corresponding any frame number.

### 5.1.3.3 Child Node

This node represents a position. The number of `position` nodes can be greater than or equal to zero.

Each position node has five mandatory attributes. Two of them are common:

- id
: A number which is unique in the positions node.

- path
: A path corresponding to the position.

The rest attributes depends on its parentâ€™s coordinate attribute.

- If coordinate = "cartesian"
The attributes are `x`, `y`, and `z` that represents the coordinate. The unit is [mm].

- If coordinate = "polar"
The attributes are `azimuth`, `elevation`, and `radius` that represents the coordinate. The unit of degree for azimuth and elevation, and mm for radius, respectively.