View source for Heat Module overview

== Ingredients ==
The calculation of the Heat Stress Overlays takes into account:
* Meteorological circumstances such as:
** Sun angles, [[altitude]] and [[azimuth]], dependent on date and time of day and project location.
** air temperatures, ([[hourly]], [[daily minimum]] and [[maximum]]);
** global radiation
** relative humidity
** wind speeds, measured and [[calculated by translation]].
* Spatial situation, such as:
** Land use, for fraction vegetation and rate of evaporation ([[Bowen ratio]]).
** Terrain, foliage and building heights

== Setup ==
Generally, the steps required to use the Heat Stress Overlay are as followed:
# Determine the location and area of interest and generate a project for that area;
# Add the Heat stress overlay;
# Open the Heat stress overlay wizard to kick off the configuration process.

====Date and time of day====
# Configure for which date you want to generate results for. This can be one day or multiple consecutive days when using the Heat Overlay Wizard.
# Configure per day which hours you want to generate results for. Each day-hour combination will become a result. This result is stored as a time-frame to relate it back to the day and time.

====Generated sun parameters====
For each day, and for each time of day, the following will be automatically generated when using the wizard:
# The day and time pairs, along with the project location, will be used to automatically calculate the sun altitude and azimuth angles for each day-time pair. 
# The sun daily motion factor is a parameter used in the atmospheric temperature formula. It will be automatically selected from the sun motion factor table, based on the date (column) and time of day (row).

====Daily Values====
Next, manually determine which weather station you want to use as a reference. Download the historical hourly weather data for that station and use certain columns as input.
In a nutshell, using the weather data, you have to supply:
# the minimum and maximum temperature of the day;
# the average wind speed, measured at the height of 10 meters;
# global sun radiation during sun hours;
====Hourly Values====
For each time of day, for each day selected:
# The hourly temperature and humidity;
# The hourly sun radiation, as an average of the current and previous hour;
# The hourly wind speed;

====Foliage Height====
Select what source will define the Foliage height:
* Buildings with [[Function|functions]] related to foliage. The [[Foliage_height_calculation_model_(Heat_Overlay)|foliage height calculation model]] will determine the foliage height using the height of the vegetation (as buildings) and the foliage crown factor attribute;
* Areas with as foliage height attribute, defining the foliage height for a whole area;
* [[GeoTiff]], defining a foliage height value for each cell in its raster.