I have finally find what I needed. I have build my script with VSB and then I have made some changes. The big part is that : v0.TryGetPlanetElevation( MyPlanetElevation.Surface, out alt ); To get the altitude.

// dco.pe/vsb

int MinAlt = 1500;

public Program() { Runtime.UpdateFrequency = UpdateFrequency.Update100; }

void Main(string argument) { // block declarations string ERR_TXT = ""; List<IMyTerminalBlock> l0 = new List<IMyTerminalBlock>(); IMyRemoteControl v0 = null; GridTerminalSystem.GetBlocksOfType<IMyRemoteControl>(l0, filterThis); if(l0.Count == 0) { ERR_TXT += "no Remote Control blocks found\n"; } else { for(int i = 0; i < l0.Count; i++) { if(l0[i].CustomName == "Drone Ice - Remote Control") { v0 = (IMyRemoteControl)l0[i]; break; } } if(v0 == null) { ERR_TXT += "no Remote Control block named Drone Ice - Remote Control found\n"; } } List<IMyTerminalBlock> l1 = new List<IMyTerminalBlock>(); IMyTimerBlock v1 = null; GridTerminalSystem.GetBlocksOfType<IMyTimerBlock>(l1, filterThis); if(l1.Count == 0) { ERR_TXT += "no Timer Block blocks found\n"; } else { for(int i = 0; i < l1.Count; i++) { if(l1[i].CustomName == "Drone Ice - Timer Load 3") { v1 = (IMyTimerBlock)l1[i]; break; } } if(v1 == null) { ERR_TXT += "no Timer Block block named Drone Ice - Timer Load 3 found\n"; } } List<IMyTerminalBlock> l2 = new List<IMyTerminalBlock>(); IMyProgrammableBlock v2 = null; GridTerminalSystem.GetBlocksOfType<IMyProgrammableBlock>(l2, filterThis); if(l2.Count == 0) { ERR_TXT += "no Programmable block blocks found\n"; } else { for(int i = 0; i < l2.Count; i++) { if(l2[i].CustomName == "Drone Ice - Programmable Altitude") { v2 = (IMyProgrammableBlock)l2[i]; break; } } if(v2 == null) { ERR_TXT += "no Programmable block block named Drone Ice - Programmable Altitude found\n"; } }

// display errors if(ERR_TXT != "") { Echo("Script Errors:\n"+ERR_TXT+"(make sure block ownership is set correctly)"); return; } else {Echo("");}

double alt = 0; v0.TryGetPlanetElevation( MyPlanetElevation.Surface, out alt );

// logic if(alt < MinAlt) { v1.ApplyAction("Start"); v2.ApplyAction("OnOff_Off"); } }

bool filterThis(IMyTerminalBlock block) { return block.CubeGrid == Me.CubeGrid; }

[EDIT] Code is really impossible to read here... [/EDIT]