Vector Calculations on Geographic Data

I have four geographical points: P1, P2, P3 and P4. The coordinates (latitude & longitude pairs) of these points are available. I want to calculate the scaler product between the two vectors P1P2 and P3P4. How can I perform this calculation in Matlab?

Note: These geographic coordinates are relevant to a specific datum (for example: WGS84) and hence do not assume the earth to be spherical.

If these types of calculations are not possible with Matlab, does anybody know a software that can be used for this purpose?

Please help

Answer 1

[Walter Roberson]

How would you solve the problem in classical geometry, finding the scalar product of (x1,y1,z1) to (x2,y2,z2) when neither z1 nor z2 were known?

[Devinya Herath]

Then, is there a way to calculate the scaler product if Z coordinates of these geographical points are available? How?

[Walter Roberson]

In classical geometry, scalar products are simple.

I would expect that in pure spherical geometry that the equivalent of scalar products have probably been studied well enough to be tractable.

But in an impure spherical geometry, I am having difficulty in deciding what the desired properties of a scalar product would be.

What is it that you are trying to _do_? Calculate the length of the geodesic?

[Devinya Herath]

I have a set of trajectory segments (segmets come from different trajectories). Starting point and the ending point of each segment is known in terms of latitude and longitude. The altitude values of all the points are the same (a fixed but unknown value). Hence all points can be considered in one plane.

I want to take two segments at a time and calculate their dot product. This value (dot product) is then used to calculate the closeness of the two segments depending on a distance measure defined by me.

[Walter Roberson]

The altitude values are the same, but you want the WGS84 model to be followed anyhow ??

[Devinya Herath]

yes. These points are assumed to be at the same hight above (or below) the reference ellipsoid WGS84