Simpler demo

[fgnievinski]

We need a simpler demonstration of:

• delay for fixed satellite elevation (10 degrees) and varying antenna height (zero to 500 m)
• delay for fixed antenna height (10 m) and varying satellite elevation (zenith to spherical horizon)

Two figures with line plots only.

[fgnievinski]

you could adapt from the demonstrations of curv-altimetry

[vitorhjr]

The simpler demos are available.

• Height variation: https://github.com/vitorhjr/geo-alhazen/blob/main/demo/demo1_simpler.m
• Elevation variation: https://github.com/vitorhjr/geo-alhazen/blob/main/demo/demo2_simpler.m