**Namespace:** Zeptomoby.OrbitTools.Track**Assembly:** Zeptomoby.OrbitTools.Track (in Zeptomoby.OrbitTools.Track.dll) Version: 1.5.0.0 (1.5.0.0)

# Syntax

C# |
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public static AzElTime OriginPlaneCoord( Satellite satA, Satellite satB, DateTime utc ) |

Visual Basic |
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Public Shared Function OriginPlaneCoord ( _ satA As Satellite, _ satB As Satellite, _ utc As DateTime _ ) As AzElTime |

Visual C++ |
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public: static AzElTime^ OriginPlaneCoord( Satellite^ satA, Satellite^ satB, DateTime utc ) |

#### Parameters

- satA
- Type: Satellite

The observing satellite.

- satB
- Type: Satellite

The target satellite.

- utc
- Type: System..::..DateTime

The time for which the coordinates are calculated (UTC).

#### Return Value

A AzElTime object containing the time, the azimuth in radians, and the elevation in radians.# Remarks

This method determines the azimuth and elevation coordinates of a target satellite relative to the position of an observing satellite in its "origin plane". The origin plane contains the observing satellite and the ECI coordinate space origin (center of the earth). The origin plane is further oriented such that the intersection line of the plane and the earth's equatorial plane forms a right angle with the line between the observing satellite and the origin. Note that when a satellite is in the equatorial plane, the origin plane and the equatorial plane are the same.

For an observing satellite on the origin plane, azimuth 0 always points to the center of the earth, and proceeds clockwise when viewed from the direction of the earth's north pole. Azimuth is always in the range [0, 2*PI).

Positive elevation indicates elevation "above" the origin plane (towards the direction of the earth's north pole), and negative elevation indicates elevation "below" the origin plane (towards the earth's south pole). Elevation is always in the range [-PI/2, PI/2].