About altitude

[Marcius1979]

Hello Folks,


Maybe this will sound stupid... But I'm curious! If I take off from the top of the mountain 400 feet high over the sea level, how the drone will merge the real altitude? The drone will go down soon flies off from the mountain area ? LOL! I have my little breeze so I never tried something like that before but now with my q500 it's different... I see a lot videos on youtube people doing that and no comments about this. So I believe there is no problem. But does not hurt to ask here! Thanks !!

 

[AeroJ]

There's 'what the craft will do', and 'what is legal in your country', which are usually different. For example, most UAVs can go as high as they have battery pack capacity for, but usually have an inbuilt limit of 400 ft so that they comply with UAV law. But that is calculated from take-off point. In the UK, the rule is 400ft AGL (above ground level), so in theory if you take off at the top of a mountain, and then fly out to the valley below, then you should reduce your height accordingly so that you are not more than 400 ft above ground level where the craft is.
But the opposite is also true - you can launch at the bottom of a hill, then climb it, and go to 400 ft above the top of it when you get there.

However laws in some other countries, like the US for example, do allow UAVs to be 400 ft above 'obstacles' so that if you are inspecting a high mast or similar you can go 400 ft above its summit in the (confusingly also 400 ft) area immediately around it.

But I'm sure you can spot the problem with any of these rules - our machines currently give us altitude readouts based on the take-off point, and driven by rather inaccurate and constantly varying barometers, so we actually have no reliable instant way of knowing what our AGL height is once we are over terrain that is at a radically different height from that at the launch point.

To be able to calculate this real-time, you'd have to have memorized an elevation map of the area, and would need to be doing constant mental arithmetic to work out what the legal height of the UAV should be at any given time and position. I would argue that this would take a considerable portion of available brain-power that would be far better directed to the safe flying of the aircraft !

 

[DrNewcenstein]

They can't really regulate "sea level", since that's different for different areas of the country. What the regs do state is GROUND LEVEL, meaning the ground you're standing on. If your property is already 400 ft above sea level, you'd be hosed, so it's ground level.

 

[CrashALot]

sea level varies little though, the atlantic is 20cm higher than the pacific ocean !

i assume that EU/UK/Brexit & such nations users can 'lie' and tell their Q500 systems they are in another country and thus BOTH their communications elec limits (much less than US power for instance - 300mw vs 25mw or something like that, which is HUGE for distance-especially 5.8ghz) can be made higher and the altitude limits can be diff/higher too, according to the f/w they load into st10+/Q ?

plus i heard there are higher limit settings you can set a USA Q as well, must go deep into flight settings or somewhere.

GL w/ your BB refurb OP !!

 

[AeroJ]

i assume that EU/UK/Brexit & such nations users can 'lie' and tell their Q500 systems they are in another country and thus BOTH their communications elec limits (much less than US power for instance - 300mw vs 25mw or something like that, which is HUGE for distance-especially 5.8ghz) can be made higher and the altitude limits can be diff/higher too, according to the f/w they load into st10+/Q ?

Yes, you'd be right about that, and it must be tempting for anyone in the EU to just use US firmware, especially on the Typhoon H, if they are in the majority of people who lose video feed for minutes most times they raise their landing gear, but there are advantages to the UK / EU software too - frequency hopping for example, which isn't in the US firmware. I find that apart from that not inconsiderable annoyance, the range I get from the UK firmware is totally adequate, and I very rarely get video drop-outs, and have never lost RC control. Still - I fly within VLOS, and rarely further than 600 ft out, so I find there is still plenty of headroom with the restricted TX power.