The functions in this section provide the user extended geometry tools for laser weapon applications.
Name 
Description 
Change the down range along a spherical earth surface between two ECF position vectors. The platform will be moved to a new location corresponding to desired down range, rd, while keeping the platform altitude fixed. Output is the new platform ECF position. To move the target instead of the platform, use ReverseGeom.  
Computes the altitude at which there is a clear line of sight from the platform to the target given a downrange along a spherical Earth and an altitude of the cloud tops.  
Returns lat, long, alt vector for common sites. If SiteID is unspecified, i.e. CommonSites, available sites are displayed in command window. Also returns a cell array of available sites when SiteID is unspecified. Thus, cell2Excel(CommonSites) produces an Excel spreadsheet of available common sites. The altitude returned is consistent with that returned from GrdAltProfile using 3arcsecond resolution DTED data.  
Computes the altitude above the surface of a spherical earth for a ray going from hp to ht at downrange rd for normalized position x (x = 0 at hp, x = 1 at ht). Also returns slant range (L) and elevation angle (el) in radians. If the geometry is input as a structure, an oblate earth model can be used and altitudes will be above the oblate earth surface.  
Converts coordinate frame from earthcentered fixed (ECF), in which the coordinate frame is fixed to the rotating earth, to earthcentered inertial (ECI), in which the coordinate frame is fixed at a specific time.  
Converts coordinate frame from EarthCenterFixed (ECF), in which the coordinate frame is fixed to the rotating earth, to local EastNorthUp (ENU) relative to a fixed location on the earth.  
Converts coordinate frame from earthcentered fixed (ECF), in which the coordinate frame is fixed to the rotating earth, to a latitude, longitude, altitude (LLA), heading, velocity description.  
Converts coordinate frame from earthcentered inertial (ECI), in which the coordinate frame is fixed at a specific time, to earthcentered fixed (ECF), in which the coordinate frame is fixed to the rotating earth.  
Converts coordinate frame from local eastnorthup (ENU) relative to a fixed location on the earth to earthcentered fixed (ECF), in which the coordinate frame is fixed to the rotating earth.  
Calculates the normal of each facet from a list of vertex point and associated facets  
Returns a (array of) structure(s) with geometry information for position and velocity of a target as a function of time. Position and velocity information for the platform will be taken from input C.G. Target information will be taken from C.Targ unless C.Targ.Flyout is empty, in which case target information will be taken from C.G and constant velocity (speed and heading) will be assumed. This function supports three trajectory "types" in the Targ.Flyout structure:
 
Function to compute a new LLA position given an LLA starting position, the forward Azimuth, and the down range using forward reckoning and great circles.  
Takes an altitude grid and Lat/Long vectors and Lat/Long points of interest and returns their respective altitudes  
Returns logical 1 if the slant path from the platform to the target does not intersect the surface of the earth.  
Determines whether the hit point on an object is close to the specified aimpoint given the geometry. The function compares Targ.Object.hitPoint (or Targ.HELpt if Targ.Object.hitPoint is empty) to the output of ObjectIncidence. The function will return false where the aimpoint is not within line of site from the platform, including the case where an aimpoint is specified internal to the object.  
Converts coordinate frame from a latitude, longitude, altitude (LLA), speed, heading description to earthcentered fixed (ECF), in which the coordinate frame is fixed to the rotating earth.  
Computes the effective spherical Earth radius as function of latitude.  
Computes full angle between platform velocity vector and propagation vector from platform to target. Also returns decomposition of full angle in elevation and azimuth.  
Computes incident angle for a given target and geometry. If Targ has a structure field Object containing facets and vertices, the incidence angle is computed based on those. Otherwise, the incidence angle is computed assuming a missile.  
Finds if and where a ray intersects an object.  
Returns the value of a physical constant given a string identifier.  
Reverses the input geometry making the target position and velocity the platform position and velocity and vice versa.  
Rotates an object as defined in Targ.Object from TargStruct based on a desired direction of motion and zenith direction.  
Returns position vectors in earthcentered fixed (ECF) coordinates of specific locations along a path between a platform and a target.  
Returns geometry structure with platform and target position, velocity in ECF coordinates given a simplified list of input geometry specifications. Target will be placed at Lat = 0, Long = 0 at specified altitude, and platform will be located on the prime meridian (Long = 0) in the southern hemisphere at a latitude consistent with the input platformtotarget ground range, rd. Assumes level flight of platform and target at (optional) specified headings. If speed of platform or target not specified, vp, vt default to zero. If heading is not specified for platform, target, or wind, heading = 90 degrees (due... more  
Converts a slant range to a downrange along the curvedearth surface  
Converts a slant range at a given elevation angle to a downrange along the curvedearth surface and a target altitude  
Returns unit vectors in earthcentered fixed (ECF) coordinate system defining a targetbased coordinate system from a platform to target, with propagation vector K from platform to target, and transverse directions oriented with the velocity vector of the target.  
Computes the angular separation between two points on a target as seen from the platform. The input points should be specified in target P/T coordinate frame.  
Computes altitude above terrain for a series of phase screens along a given path. Also returns the terrain altitude and the locations of the phase screens in LLA coordinates.  
Computes the lineofsight velocity transverse to the propagation direction along the path for platform motion, target motion, and natural wind. Assumes coordinate system rotated to be aligned with target transverse velocity vector.  
Rotates velocity vector from target T/P coordinates, or some other coordinate frame, into the desired coordinate frame. Rotation is based on the angle between the projection of the zenith direction onto the target plane, i.e. the plane transverse to the propagation direction, in target T/P coordinates vs. the userspecified zenith projection.  
Returns site information for location from CommonSites which matches to the input geometry information. If no match, returns 'UNKNOWN'. If G structure is passed in, info for platform and target are returned. If LLA vector passed in, single site is returned. 
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