Z and M values,

I couldn�??t make a proper distinction between the Z and M values in the ArcGIS.

If the Z value indicates the third dimension (elevation) that generates the mathematical (X, Y, Z) point to describe the location of a particular location. what does M stand for?

No proper documentation that shows graphically the Z and M value

Thank you

Best

Jamal

I couldn�??t make a proper distinction between the Z and M values in the ArcGIS.

If the Z value indicates the third dimension (elevation) that generates the mathematical (X, Y, Z) point to describe the location of a particular location. what does M stand for?

No proper documentation that shows graphically the Z and M value

Thank you

Best

Jamal

Z is elevation. It is primarily used in conjunction with the ArcGlobe and ArcScene applications. They are typically defined relative to sea level. Here is a graphic that partially shows Z values in operation.

M is relative measures along a line that can represent any unit of measure. For example, it can be the relative distance between nodes on the line based on line length in any units of length that are convenient (feet, miles, meter, km, etc). Alternatively they could represent the amount of time it took an animal to move from node to node based on GPS data date time values in decimal days or hours. Yet again it could be the average time required for a vehicle to travel from node to node based on speed limits. So M values are flexible. Here is an illustration showing M values based on relative lengths along the line graphically and how they can be used to define positions along the line for various attribute segments or points. Here is another illustration of their use for defining events at relative positions along the line based on length. Linear Referencing is primarily for used asset management of features that follow a line path.