Ho rispolverato i libri di geometria piana…
…ricordo che qualche pigro topografo giocava con G_Earth e che in effetti dava risultati
soddisfacenti,senza far storcere il naso ai geometri ortodossi.
The technique used is to convert the WGS84 coordinates into UTM plane coordinates.
You have to pay attention to the zone you use and stay within it.Google Earth Pro can do it.
E.g. U have 34,801472°N , 114,083487°W
into search_bar as placemark
then go in tools_options and

then R_click on the placemark and in properties can see UTM coordinate.
take note
766818.31 m E ; 3854905.21 m N
are the plane coord. (
to use in a cartesian p.in meters)
the formula to calculate the distance between two points is:
d = √((x2 - x1)² + (y2 - y1)²)
where x=easting & y=northing
need the Unit_vector as
( (x2 - x1) / d, (y2 - y1) / d )
and the Displacement_vector of
n meters as
n( (x2 - x1) / d, (y2 - y1) / d )
so need to add the n*Unit_vector couple to the first point:
e.g. for 100m distance ,if the couple of Unit_vector is (0.69,0.71) will be
(x1 + 69,y1 + 71) if the
bearing y=Northing go to north…(as in A)
let say second point has 766947.00 m E ; 3850370.00 m N
need distance:
d=766947.00-766818.31= (128.69)²=16561.1161
3850370.00-3854905.21=(-4535.21)²=20568129.7441
16561.1161+20568129.7441=√20584690.8602=4537.03547046m
now Unit_vector:
U_v_x=766947.00-766818.31=(128.69)/4537.03547046=0.02836433632
U_v_y=3850370.00-3854905.21=(-4535.21)/4537.03547046=-0.99959765127
U_v=[|0.02836433632 , 0.99959765127|] ( | mean absolute value)
if U see the
second point (B) has x positive and y negative and the vector_direction coordinate are (x,-y)
instead if the second point is in C it has (-x,-y) and so on
So,take a point at 150m…
150 (0.02836433632 , 0.99959765127) → |(
±4.254650448 ,
±149.939647691)|
so
766818.31+4.254650448=766822.56465 for x
3854905.21
- 149.939647691=3854755.27035 for y
P150m has
766822.56465 m E ; 3854755.27035 m N
that in WGS84 is
now U can mark points and convert into kml or gpx…for other apps.
A programmer would be needed for the auto-calculations.