Sun Data

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Sun Data

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Applies to International.

 

The Sun Data property is used to specify the origin of the data used to convert Sun Tokens, and any specific calculation options that should be used.

 

On the left of the Sun Data property editor is a list of Available Sun Data Sources. Use the Add and Remove buttons to fill the list of Selected Sun Data Sources to the right. Usually you will only select one Sun Data Source per diary, if any.

 

If you often use the same Sun Data source and options, you can set a default to use for any new script, using the Preferences.

 

If you need to select more than one Sun Data Source, then make sure that the selected sources are listed in the order that you will refer to them in Sun tokens. For example, if you are building a table of sunrises/sunsets for many cities, then the [SR1] and [SS1] tokens will use data from the first source listed in the list, the [SR2] and [SS2] tokens will use data from the second source, etc...

 

This property should not be confused with Moon and Sun Options, which is used to defined how Sun events are displayed for each individual DiaryGridLine. The Sun Data property deals with obtaining the Sun information, while the Moon and Sun Options property deals with displaying this information.

 

If you have selected a Calculated Sun Data Source (recommended), then you should specify the Calculation Options to be used in the calculation of Sun Events :

 

Ignore Summer Times, even if source uses them

(not recommended)

If you select this option, then all sun-related times will be calculated and displayed as if the location used to calculate them did not follow summer time rules. This is not recommended as it will provide times that are an hour off from readers' experiences for half of the year. The only reason to use this option is to match customer data which may have neglected summer time effects by error.

 

The following options only affect the calculated times for sunrise and sunset.

 

Ignore atmospheric refraction
(not recommended)

If you select this option, then calculation of the times of sunrise and sunset (as displayed using the tokens [SR] and [SS]) will be performed without taking into account atmospheric refraction (the bending of light around the Earth due to the atmosphere). Turning this option on is not recommended as it will produce sunrise times that are later than the observed times, and sunset times that are earlier than those observed. The only reason to use this option is to match customer data at any cost.

Use fixed disk sizes
(not recommended)

If you select this option, then calculation of the times of sunrise and sunset (as displayed using the tokens [SR] and [SS]) will be performed without taking into account the fact that the Sun is not always at the same distance from the Earth. When the Sun is at the closest (in January) it looks larger and therefore appear rises sooner and sets later than if one assumes a fixed disk size. Turning this option on is not recommended, and only reason to use this option is to match customer data.

Reference point for rise/set calculations

Normally the time of sunrise is defined as the moment when the top of the Moon becomes visible, and sunset as the moment when the top of the Moon disappears below the horizon. This corresponds to the value Top of Disk which is the default setting and should only be changed if you are sure of the consequences of that change, usually to match existing customer data.

 

The time calculated for Dawn and Dusk depend on the value of the Definition used to calculate them. The most commonly accepted values are available from the drop down list, and if really necessary, you can specify your own values.

 

Definition

There are many definitions of dawn and dusk, most depending on the angle of depression of the sun below the horizon. The most commonly used religious and civil angles are available in the drop-down list, but you can also specify your own angle, by selecting the Specific Angle option. You can also specify that dawn and/or dusk will be defined as a set number of minutes before sunrise or minutes after sunset (this is used in the UK and New Zealand, for example, to determine at what time drivers should turn on their headlights).

Deg. and Min.

If you select Specific Angle in the list of Definitions, then you are given the possibility of specifying the degree and minutes components of the Depression Angle yourself (not recommended).

 

Usually, unless you are calculating dawn and dusk for religious purposes, you should use the Nautical Twilight values, which seem to correspond the best to the concept of first light and last light (civil twilight seems to be used mainly for unpleasant things such as curfews and dawn firing squads).

 

The present property is used to determine what time are calculated for various sun event. The options used to display this information are set in Sun Options of each individual DiaryGridLine.


Topic 69000 updated on 12-May-2016.
Topic URL: http://www.qppstudio.net/webhelp/index.html?sunrise_sunset.htm