Beside the "Radar Altitude" any other way to determine the 'current altitude'?

[Sirine]

The "Radar Altitude" are best in determine the actual altitude direct below our ship but unfortunately it only show at 3k meter and below...which is too late for most of the time.

I have try to drop something downward but the drops destroy upon contact on the surface.

I can have a brief moment to know how far away I'm from the actual surface. But that brief moment really not that helpful.

So, anyway beside reading that "radar altitude" from IVA? Or anything that drop and not that easily destroy?

[KvickFlygarn87]

Well, I believe Kerbal Engineer would do it, or MechJeb.

[Mr Shifty]

Steam Gauges beta also has a radar altimeter:

http://forum.kerbalspaceprogram.com/showthread.php/39617-WIP-SteamGauges-Beta-release-1-3b1

[capi3101]

KER or Steam Gauges; both have radar altimeters, both are extremely useful. As for dropping something without it breaking, try getting it to land on a part with high impact tolerance (such as structural panels, modular girders, and especially structural pylons). I've dropped one of my Hellhound rovers from 2500 meters on Kerbin before, land at 70 m/s and survive (broke off a few tires and popped a few more of course, but the thing was still drive-able afterward) because it's largely constructed with high speed-impact tolerant parts.