Hi, Tom

Let's have another view of the problem ...

You get an altitude measurement, ...but what is your sensor ??? and mostly what is its precision ???

I do not know lots of altitude sensors seriously able to give 1 cm on a hundred meters ... 1/10 000 precision, you sure ??? ... !!!

May be a little look here could reduce your number sizes ...and simplify you work.

24 and 32 bits arithmetics can be downloded from Melabs site ... if you really want to keep "ghost" centimeters !!!

Alain