Spacecraft.Access(Variable, Sensor) Method

Returns the start time, end time, and duration of a Spacecraft's Sensor's view of celestialBody. The Access time is based on the specified sensor(s).

Note: This is an interval method. See the Interval Methods page for more information.

Method Signature

Arguments

celestialBody

Description:

The numerical identifier for the celestial body that the calling Spacecraft is attempting to access. Body ID's 1-11 are assigned to the default Solar System objects, as shown below. Custom CelestialObjects will have body ID's starting at 12 and assigned in the order they are created.

Valid Values:

Celestial Object	Value
Mercury	Mercury.BodyID or 1
Venus	Venus.BodyID or 2
Earth	Earth.BodyID or 3
Mars	Mars.BodyID or 4
Jupiter	Jupiter.BodyID or 5
Saturn	Saturn.BodyID or 6
Uranus	Uranus.BodyID or 7
Neptune	Neptune.BodyID or 8
Pluto	Pluto.BodyID or 9
Moon	Moon.BodyID or 10
Sun	Sun.BodyID or 11
<Custom CelestialBody>	<Custom CelestialBody>.BodyID, starting at 12 and assigned in the order the custom CelestialObjects are created.

Return Value

Returns the start time, end time, and duration of a Spacecraft's Sensor's view of celestialBody. The Access time is based on sensor.

The FF_Preferences.IntervalEventReportingBehavior property controls whether the start and end of propagation are reported as events. By default, if the Sensor's view starts before the beginning of the propagation span, FreeFlyer will label the start of the propagation as the start of the Sensor's view. If the Sensor's view extends past the end of the propagation span, FreeFlyer labels the end of propagation as the end of the Sensor's view.

Syntax

This example shows how to generate a report of access from a Spacecraft to a Variable (representing a CelestialObject) using only the specified Sensor on the Spacecraft.

Spacecraft Spacecraft1;

// Configure Spacecraft orbit and add a Sensor to be used by the Spacecraft.Access() method

Spacecraft1.I = 0;

Spacecraft1.AddSensor("Sensor_1");

Spacecraft1.Sensors[0].BoresightUnitVector = {0, 0, -1};

// *** For Millisecond Mode Only ***

While(Spacecraft1.ElapsedDays < 0.25);

Report Spacecraft1.Access(10 /*Body ID for the Moon*/, Spacecraft1.Sensors[0]) to "Spacecraft_Access_Variable_Sensor.txt";

Step Spacecraft1;

End;

// *** For Nanosecond Mode Only ***

While(Spacecraft1.ElapsedTime < TIMESPAN(0.25 days));

Report Spacecraft1.Access(10 /*Body ID for the Moon*/, Spacecraft1.Sensors[0]) to "Spacecraft_Access_Variable_Sensor.txt";

Step Spacecraft1;

End;

Output:

Note: Output generated using nanosecond timing precision mode.

Access Event Entry Epoch Exit Epoch Duration(min)

Moon --> Sensor_1 Jan 01 2020 00:50:38.012695312 Jan 01 2020 01:05:57.055664062 15.317382813

Moon --> Sensor_1 Jan 01 2020 02:29:32.900390625 Jan 01 2020 02:44:55.019531250 15.368652344

Moon --> Sensor_1 Jan 01 2020 04:08:27.714843750 Jan 01 2020 04:23:52.983398437 15.421142578

Moon --> Sensor_1 Jan 01 2020 05:47:22.602539062 Jan 01 2020 06:00:00.000000000 12.623291016