﻿IsoElevationCircleEcf Method (, , , Double, Double, Double)
Calculates an elevation circle on an ellipsoid model.

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 List<Ecf> IsoElevationCircleEcf(
this WgsModel ellipsoid,
EciTime subpoint,
Eci target,
double degAngle,
double kmSpacing,
double kmLoft
)```
Visual Basic
```<ExtensionAttribute> _
Public Shared Function IsoElevationCircleEcf ( _
ellipsoid As WgsModel, _
subpoint As EciTime, _
target As Eci, _
degAngle As Double, _
kmSpacing As Double, _
kmLoft As Double _
) As List(Of Ecf)```
Visual C++
```[ExtensionAttribute]
public:
static List<Ecf^>^ IsoElevationCircleEcf(
WgsModel^ ellipsoid,
EciTime^ subpoint,
Eci^ target,
double degAngle,
double kmSpacing,
double kmLoft
)```

#### Parameters

ellipsoid
Type: WgsModel
The ellipsoid model.
subpoint
Type: EciTime
The center location of elevation circle.
target
Type: Eci
The target location.
degAngle
Type: System..::..Double
The viewing angle, from the circle center to the target location, [0..90] degrees.
kmSpacing
Type: System..::..Double
The distance between each point in the circle, in kilometers.
kmLoft
Type: System..::..Double
The height of the circle above the earth ellipsoid model, in kilometers.

#### Return Value

A list of ECF coordinate points that form a circle on the ellipsoid, centered around a given subpoint location. The points all have the same viewing angle of elevation to the given target location.

#### Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type WgsModel. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .

# Remarks

The returned points do not always form a perfect circle due to the Earth's equatorial bulge.