Receivers

The Receivers model object is used as a container for all the Receivers in the situation.

Overview

Each Situation is assigned a set of Receivers as a single library object, containing the names and locations of all the pass-by and standstill Receivers.

An individual Receiver is defined as a sound pressure evaluation point. It is the sound pressure results at these Receiver locations that will be output in the calculation results.

There are two different types of sub-sets of Receivers:

• Pass-by Receivers are used when the train speed is more than 0 m/s. These have a fixed position in the x axis (track longitudinally).
• Standstill Receivers are used when the the train speed is exactly 0 m/s. These can be positioned at any desired location around the train.

The main standstill receivers item in the model browser presents an option for the receiver heights used in the calculation of the LpUnit parameter. The default is for only the standard receiver positions (i.e. 1.2m height) to be used in the LpUnit calculation, but 3.5m height positions can additionally be used to provide results for a LpUnit_upper parameter.

By right-clicking on the pass-by or standstill Receivers items in the model brownser, it is possible to either create individual Receivers, or create a number of Receivers at locations defined in ISO 3095:2013 (n.b. the mesh of standstill receivers will be created according to each Vehicle’s “Receiver segments” setting). Note that when Train Noise Expert calculates the LpUnit metrics, it generates its own mesh of receivers in the background that is completely independent of any receivers generated in the user interface; the option to create the ISO 3095:2013 standstill receivers has been provided for convenience, for example for users to compare individual microphone position results with measurement data.

Note, that after adding/removing Vehicles, or changing the lengths of Vehicles, standstill Receivers will need to be recreated in order to maintain correct ISO 3095 locations.

Receivers are shown in the 3D graphics view (optionally, with labels), but not in the 2D model view.

Input Parameters

Name	Data type	Unit	Comment
Label	Text	-	A label for this Receiver. This will be used to identify the Receiver in the calculation and results. Special characters are not allowed.
Position along track	Number	m	The x-axis coordinate (i.e. longitudinal distance between the front of the Train and the Receiver).
Distance from track centre	Number	m	The y-axis coordinate (i.e. lateral distance between the Track centre and the Receiver). This cannot be zero.
Height above rail	Number	m	The z-axis coordinate (i.e. vertical height of the Receiver above the rail). Must be a positive value.