Drone Flies Into an Active Volcano [video]

Also of note, winds aloft are often not the same as winds on the ground. Given top speed on these guys is around ~20mph, any wind above that and you've got a fly-away. Again, definitely doesn't account for all fly-aways, but I would venture that it does explain some.

Not sure about that distance. (I didn't see the video) The GoPro opens a wi-fi connection.

That's not quite true. It's Bandwidth + encoding = speed . And there's tons of digital encoding schemes: ASK APSK CPM FSK MFSK MSK OOK PPM PSK QAM SC-FDE TCM for starters. And those would allow you to pick up and decode using any old computer running a HDTV usb capture card that can go into raw mode.

> Maybe in a perfect world without anyone else competing for the frequencies.

Nobody would bat an eye if I was to start doing UAV control over 145.50-145.80 with a 20KHz bandwidth . I'd just hop on the local repeater and announce that is what I was doing, and have a radio listening in priority mode to it. If I heard of any anomalies, I'd shut it down and investigate what's going on.

And I have no LoS issues and 2M usually has a nice noise floor. Obviously that doesn't quite apply at night, but just stay vigilant in not harming others.

> Note about radio control that, over decades of time, the command & control frequencies have been going up. There's a good reason -- the original 27 MHz scheme was unworkable for multiple reasons, but one of them was limited bandwidth.

Tubes and early silicon made access to the lower frequencies tenable. Of course the lower frequencies will fill up first. So, it does make great sense, for higher bandwidth using services, to use high frequencies. That's why I said the video could be on the 2.4 GHz spectrum, whereas the command can be on 144MHz.

I'd also consider going lower, making AM more usable. For command frequencies, NOT having capture* is a great deal. That's why control towers mainly use AM and digital modes/CSMA variant.

*Capture is an FM phenomenon, where the strongest FM signal that hits a receiver is the only signal the receiver can hear. The receiver is literally captured to that station. AM does not have that, and what you hear is the jumble of every station in range. Just tune at night on AM and you can hear this.

As with most things, several things had to come together in order for this to happen. A probably incomplete list.

1) Lithium chemistry batteries - unlike Nickel, Cadmium, or Lead chemisty batteries, Lithium batteries are have a lower weight per watt-second than the others.

2) Micro-Electro-Mechanical-Systems (MEMS) - which is a technique for building a mechanical system (like a balance beam) using the same processes that create integrated circuits. This opened up developing accelerometers, gyroscopes, and magnetometers where the sensor and the conditioning circuit were all in the same silicon die. That hugely lowered the cost of such things, and has evolved to the point of providing 9 degree of freedom systems that are on one, or two inexpensive chips.

3 - Cheap 32 bit Micros - Emergence of inexpensive 32 bit microprocessors with DSP like features. The ARM Cortex M series in particular. Even with a cheap inertial sensor you need to process it fast enough and with enough precision to act. DSPs can do this but they are complex, difficult to program, and development tools are expensive. 32 bit ARM processors are easily engaged by high school students using off the shelf free tools.

4 - High performance MOSFETs (low Rds(on) resistance), cheap hall effect sensors - these allowed people to build brushless motors with atonishing power to weight ratios. From CD-ROM spindle motors putting out 1/2 HP for electric planes to 15W motors the size of pager motors which are quite light weight.

Of course that all of this stuff is light weight gets the weight down to the point where you have enough power to lift it, and the integration gets the costs down to where you can build something on a small budget (a few hundred dollars, well within the budgets of active modelers)