Displaying vectors with origin and direction in Google Earth - kml

Question

Would like to display direction vectors at defined locations in Google Earth. In a 3D tool direction vectors differ from a position vector (i.e. 2 geographical points connected via a line) that the displayed size is independant of the zoom level, just dependant on the aspect angle (projection).
Side mote: Finally I would like to display 3 direction vectors which span a orthoganal coordinate frame. So each "vector" would point in 3D Space.
Any solution existing? Or any idea of workaround for it?
I am familiar with KML and already reached my first goal to display a ground track and to highlight areas of interests using polygons. However I have found no solution for my request.

Answer 1

You can create points with icon images that look like an arrow, and rotate them with the appropriate tags, like in the KML below. Try copy/pasting that into Earth Pro.
Note that in this example I used an easily available icon where the arrow points down, but you might want to use your own where the arrow points up, so that the icon heading matches the compass angle. Also, you can play with the icon hotspot tag, to define what part of the icon image is anchored at your point's lat/lon. In this case I used the center of the image, but you could use the origin or tip of the arrow if you wanted.
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" xmlns:gx="http://www.google.com/kml/ext/2.2" xmlns:kml="http://www.opengis.net/kml/2.2" xmlns:atom="http://www.w3.org/2005/Atom">
<Document>
<name>arrow icons with headings</name>
<Placemark>
<name>heading: 0</name>
<Style>
<IconStyle>
<scale>3</scale>
<heading>0</heading>
<Icon>
<href>http://maps.google.com/mapfiles/kml/shapes/arrow.png</href>
</Icon>
<hotSpot x="0.5" y="0.5" xunits="fraction" yunits="fraction"/>
</IconStyle>
</Style>
<Point>
<coordinates>-90,38</coordinates>
</Point>
</Placemark>
<Placemark>
<name>heading: 75</name>
<Style>
<IconStyle>
<scale>3</scale>
<heading>75</heading>
<Icon>
<href>http://maps.google.com/mapfiles/kml/shapes/arrow.png</href>
</Icon>
<hotSpot x="0.5" y="0.5" xunits="fraction" yunits="fraction"/>
</IconStyle>
</Style>
<Point>
<coordinates>-85,38</coordinates>
</Point>
</Placemark>
<Placemark>
<name>heading: 150</name>
<Style>
<IconStyle>
<scale>3</scale>
<heading>150</heading>
<Icon>
<href>http://maps.google.com/mapfiles/kml/shapes/arrow.png</href>
</Icon>
<hotSpot x="0.5" y="0.5" xunits="fraction" yunits="fraction"/>
</IconStyle>
</Style>
<Point>
<coordinates>-80,38</coordinates>
</Point>
</Placemark>
</Document>
</kml>