How to calculate 3D distance (including height) between two points in GeoDjango

Question

Prologue:

This often raises the question in SO:

• 3D distance calculations with GeoDjango
• Calculate the distance between two points using the longitude latitude and elevation (elevation)
• Distance between two 3D points in geodjango (postgis)

I wanted to make an example in SO Documentation, but the chapter was geodjangonever removed, and after the Documentation was turned off on August 8, 2017, I will follow up on this widely-spread and discussed meta-answer and write my example as an answer to my question.

Of course, I would be more than happy to see any other approach.

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Question:

Suppose the model:

class MyModel(models.Model):
    name = models.CharField()
    coordinates = models.PointField()

Where I save a point in a variable coordinateas a point lan, lng, alt:

MyModel.objects.create(
    name='point_name', 
    coordinates='SRID=3857;POINT Z (100.00 10.00 150)')

:

p1 = MyModel.objects.get(name='point_1').coordinates
p2 = MyModel.objects.get(name='point_2').coordinates

d = Distance(m=p1.distance(p2))

d=X .

:

:

p1.coordinates = 'SRID=3857;POINT Z (100.00 10.00 200)'

150 , :

d = Distance(m=p1.distance(p2))

d=X , , .
3D- ?

Answer 1

GeoDjango Distance .
3D-, , :

:

latitude, longitude altitude , (x, y, z), Euclidean Formula 3D-.

• :
  polar_point_1 = (long_1, lat_1, alt_1)

polar_point_2 = (long_2, lat_2, alt_2)

• , :

  x = alt * cos(lat) * sin(long)
  y = alt * sin(lat)
  z = alt * cos(lat) * cos(long)
  

  p_1 = (x_1, y_1, z_1) p_2 = (x_2, y_2, z_2) .

• , :

  dist = sqrt((x_2-x_1)**2 + (y_2-y_1)**2 + (z_2-z_1)**2)
  

Answer 2

numpy:

np.linalg.norm(point_1 - point_2)