﻿OriginPlaneCoord Method (, )
Determine the azimuth and elevation coordinates of a point in ECI coordinate space relative to the origin plane of another point.

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

# Syntax

C#
```public static AzEl OriginPlaneCoord(
Vector posA,
Vector posB
)```
Visual Basic
```Public Shared Function OriginPlaneCoord ( _
posA As Vector, _
posB As Vector _
) As AzEl```
Visual C++
```public:
static AzEl^ OriginPlaneCoord(
Vector^ posA,
Vector^ posB
)```

#### Parameters

posA
Type: Vector
The first coordinate point.
posB
Type: Vector
The second coordinate point.

#### Return Value

An AzEl object containing the azimuth and elevation of the second point. The data is relative to the first point's origin plane.

# Remarks

This method determines the azimuth and elevation coordinates of a target point relative to the position of an observing point in its "origin plane". The origin plane contains the observing point and the ECI coordinate space origin. The origin plane is further oriented such that the intersection line of the plane and the X-Y plane forms a right angle with the line between the observing point and the origin. Note that for a point in the X-Y plane, the origin plane and the X-Y plane are the same.

For an observing point on the origin plane, azimuth 0 always points to the axis origin, and proceeds clockwise when viewed from the direction of the positive Z-axis. Azimuth is always in the range [0, 2*PI).

Positive elevation indicates elevation "above" the origin plane (towards the direction of the positive Z-axis), and negative elevation indicates elevation "below" the origin plane (towards the negative Z-axis). Elevation is always in the range [-PI/2, PI/2].