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AstroGPS

Introduction​

On the display the astronomical mode is shown as AstroGPS Timer.

AstroGPS Timer calculates daily times using:

  • coordinates of Controller place;
  • offset UTC: of Controller place;
  • coordinates of Simulated place;
  • status of the Twilight: parameter.

Times are recalculated based on the RTC date.

The coordinates are divided into two groups:

  • Controller place: real position of the control unit, used to locate the local solar noon;
  • Simulated place: position to simulate, used to obtain day length and twilight duration.

Actual menu path​

Route:

MENU -> Use Program -> Prg: AstroGPS Timer -> ENTER

Screens displayed:

  1. Controller place / Lat:
  2. Controller place / Long:
  3. Controller place / UTC:
  4. Simulated place / Lat:
  5. Simulated place / Long:
  6. Twilight:

Controller place​

The first part of the configuration sets the real location of the control unit.

Screens displayed:

  1. Controller place / Lat:
  2. Controller place / Long:
  3. Controller place / UTC:

The control unit uses these coordinates and UTC: to calculate local sunrise and sunset and derive solar noon.

Lat:​

Set the latitude in hundredths of a degree.

The Lat: screen appears under both Controller place and Simulated place.

Display format:

N+DDD.DD or S-DDD.DD

Real limits:

  • minimum: S-066.00
  • maximum: N+066.00

Real commands:

  • LEFT and RIGHT move the cursor;
  • UP increases the selected value;
  • DOWN decreases the selected value;
  • on the position of the sign, UP or DOWN reverse North/South;
  • ENTER confirms and goes to the next screen of the current block.

Long:​

Set the longitude in hundredths of a degree.

The Long: screen appears under both Controller place and Simulated place.

Display format:

E+DDD.DD or O-DDD.DD

On the display the letter O indicates West longitude.

Real limits:

  • minimum: O-180.00
  • maximum: E+180.00

Real commands:

  • LEFT and RIGHT move the cursor;
  • UP increases the selected value;
  • DOWN decreases the selected value;
  • on the sign position, UP or DOWN reverse East/West;
  • ENTER confirm and move to the next screen. From Controller place it goes to UTC:, from Simulated place it goes to Twilight:.

UTC:​

Sets the local offset from UTC.

Display format:

+HH:MM or -HH:MM

Real limits:

  • minimum: -12:00
  • maximum: +14:00

Real commands:

  • LEFT increases by 60 minutes;
  • RIGHT decreases by 60 minutes;
  • UP increases by 15 minutes;
  • DOWN decreases by 15 minutes;
  • ENTER confirm and move to Simulated place / Lat:.

Simulated place​

The second part of the configuration sets the location to simulate.

Screens displayed:

  1. Simulated place / Lat:
  2. Simulated place / Long:

The limits and commands are the same as Lat: and Long: of Controller place.

In the calculation, the control unit obtains the length of the day and the duration of the twilight periods from the Simulated place. These durations are then centered on solar noon calculated by the Controller place.

The display does not expose a separate UTC: parameter for the Simulated place.

Twilight:The Twilight: screen allows you to enable or disable the use of twilight.​

Actual display values:

  • Enabled
  • Disabled

Real commands:

  • UP toggles the value;
  • DOWN toggles the value;
  • ENTER save and return to the main page.

When Twilight: is confirmed, the control unit uses civil twilight.

If Twilight: is disabled, the device does not use the Start Crack and End Crack traits: the start of light coincides with Sunrise and the end of light with Sunset. Base ramps start at 1 minute, while Astro transition maintains the variation for 30 minutes after Sunrise and 30 minutes before Sunset.

If Twilight: is enabled, the device uses the onset of civil twilight as the onset of sunrise and ramps up to the calculated sunrise.

Type of twilight​

In this revision the user menu manages civil twilight.

There is no user choice between nautical or astronomical twilight.

Real ramp behavior AstroGPS​

With Twilight: enabled, the control unit:

  1. calculate sunrise and sunset of Controller place;
  2. obtains local solar noon from Controller place;
  3. calculate day duration and twilight duration of the Simulated place;
  4. centers the duration of the simulated day on the local noon of the control unit;
  5. calculate Crack Start, Sunrise, Sunset and Crack End;
  6. bring the light from 0 to the twilight level between Iniz Crep and Dawn;
  7. brings the light from twilight level to maximum level in the 30 minutes following Dawn;
  8. maintains the maximum level during the day;
  9. reduces light in the 30 minutes before Sunset;
  10. Bring the light from the twilight level to 0 between Sunset and End Crep.

With Twilight: disabled, the control unit uses dawn and dusk without extending the ramps to dusk; 30 minute Astro transitions around sunrise and sunset remain.

On the main page, when the active program is AstroGPS Timer, the display also shows dedicated information screens:

  • Sunrise / Sunset;
  • Start Crack / End Crack;
  • Total light hr / Today.

Default values​

When reloading the default parameters, the control unit sets:

  • Controller place latitude: 28.29;
  • Controller place longitude: -16.63;
  • Controller place UTC offset: 0;
  • Simulated place latitude: 28.29;
  • Simulated place longitude: -16.63;
  • twilight type: Civil;
  • Twilight: enabled.

Negative longitude is displayed as West.

An initial configuration may include room 1 on AstroGPS Timer, Controller place set to the actual installation position and Simulated place set to the place whose light cycle you want to reproduce.