Add Calculations - Glare Rating

Glare rating indicates the glare evaluation for outdoor sports and area lighting based on the veiling luminance produced by the luminaires and the environment on an observer's eye. It is measured as the observer looks at each point on a horizontal illuminance grid. A lower glare rating value (GR) indicates better glare restriction. Glare rating is limited to viewing directions below eye level.

When glare rating is specified, grids are created for each observer position that duplicate the specified horizontal illuminance grid. Each GR grid is identified by its correlated observer position. Observer positions are labeled sequentially, “Obs_1”, “Obs_2”, etc. Each GR grid is identified by its correlated observer position. In Project Manager, each GR grid is identified by its observer position and calculation points label.

For example, a horizontal grid labeled football with one observer position, would have a glare rating grid associated with it called “football_Obs 1.” In Project Manager, there would be two related grids associated with “football,” the horizontal illuminance grid “football” and “football Obs_1.”

The Glare Rating calculation does not take reflective or obstructive entities around or within the GR grid into account.

From the Add menu choose Calculations - Glare Rating, or from the Calculations Toolkit select $image\calc_button-glare_rating.jpg$ .
Specify a unique label for the family of glare rating grids, up to 32 characters long. The default label will be GR_1. Unless changed, subsequent labels will be GR_2, GR_3, etc. If a number is used for the label, subsequent labels will be incremented accordingly.
An optional description may be entered (up to 80 characters). Meaningful descriptions that include size and color information will be useful when generating schedules.
Specify the point spacing from left to right and top to bottom. By default, a point spacing of 10 by 10 is used. As the point spacing changes, the text size adjusts, automatically. You may override this value once the point spacing is established, if desired.
By default, the illuminance grid is not visible. To make it visible, left click in the Illuminance Grid Visible selection box so that a checkmark is shown.
Specify the grid reflectance. Enter a decimal value > 0 and < 1.
You may center the measurement points within the grid boundary, if desired, by clicking in the selection box adjacent to Center Points Relative to Grid Boundaries.
Specify the observer positions. Each observer position will have a GR grid of its own. Observer positions are specified in one of three ways:

Specify the number of observer positions by using the up and down arrow keys next to Number Of Observer Positions. Enter the x, y, and z coordinates of each observer position and grid visibility. Initially, a coordinate of 0,0,4.92 ft (or 0,0,1.5 m) is assigned to each observer position.
Click on the Specify Additional button to specify additional observer positions in the graphics window. When the dialog is first accessed, one observer position is already located at 0,0,4.92 ft (or 0,0,1.5 m). You may also use this button to add additional observer positions to ones you have already located. The dialog will temporarily close, and you can locate the observer positions by clicking the left mouse button at each location. Right click the mouse when you are done to return to the GR dialog. Each observer position will be located at a height of 4.92 ft (1.5 m). You can change this height in the Z-Coord text box if you want.
Click on the Specify New button to delete any existing observer positions and specify all new observer positions in the graphics (Model mode) window. Locate each observer position with the mouse and left click to specify. Multiple observer positions may be specified by repeatedly left clicking at the desired locations. By default, the observer position will be located at typical eye level (4.92 ft, 1.5 m) unless otherwise specified. Once you have finished locating observers, click the right mouse button to return to the Glare Rating dialog.

In the Summary section, specify the options you would like to calculate. By default, average, maximum and minimum illuminance are displayed, along with uniformity ratios (Max/Avg ratio is not selected, by default). If Number of Points is selected, the number of points that are in each grid (not including points that have been removed) are shown.
Select the display options, including precision (decimal places), text color, perimeter lines, markers and labeling.
Specify the Z coordinates of the grid. it must be less than the Z coordinate for the observer position(s) as GR is limited to viewing directions below eye level. You will have the option to change the grid height, if desired, before specifying the first grid point.
If desired, specify Isoline contouring and Highlight Values by clicking on the appropriate buttons.
Click Ok to return to the graphics window and place the GR plane.
To change the grid elevation, move the cursor into the Z-Coord text box and enter a new value or use the up and down arrow keys on the keyboard, before clicking the first point. Locate the first point of the grid and click the left mouse button.
Drag the cursor to the second point on the grid (opposite corner) and left click again.

Note: Individual Observer Positions may be deleted by selecting the entire row. Click on the row marker to the left of the Observer Label and delete it--press Delete on the keyboard when the entire row is highlighted. You may Relabel all of the observer positions, and restore sequential labels by clicking on the Relabel All button.