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ITelescopeV3DoesRefraction Property

True if the telescope or driver applies atmospheric refraction to coordinates.

Namespace:  ASCOM.DeviceInterface
Assembly:  ASCOM.DeviceInterfaces (in ASCOM.DeviceInterfaces.dll) Version: 3351c4f3fa64146a7efd5b51ed4591e32a0a5484
bool DoesRefraction { get; set; }

Property Value

Type: Boolean
PropertyNotImplementedExceptionEither read or write or both properties can throw PropertyNotImplementedException if not implemented
NotConnectedExceptionIf the device is not connected
DriverExceptionAn error occurred that is not described by one of the more specific ASCOM exceptions. Include sufficient detail in the message text to enable the issue to be accurately diagnosed by someone other than yourself.
If this property is True, the coordinates sent to, and retrieved from, the telescope are unrefracted.

This is only available for telescope InterfaceVersions 2 and later.


  • If the driver does not know whether the attached telescope does its own refraction, and if the driver does not itself calculate refraction, this property (if implemented) must raise an error when read.
  • Writing to this property is optional. Often, a telescope (or its driver) calculates refraction using standard atmospheric parameters.
  • If the client wishes to calculate a more accurate refraction, then this property could be set to False and these client-refracted coordinates used.
  • If disabling the telescope or driver's refraction is not supported, the driver must raise an error when an attempt to set this property to False is made.
  • Setting this property to True for a telescope or driver that does refraction, or to False for a telescope or driver that does not do refraction, shall not raise an error. It shall have no effect.

See Also