The Natescape Wireless Video Webification System™ consists of a camera, transmitter, and receiver from Polaris Industries, a camcorder from Sony, and an IEEE 1394 (FireWire / iLink) board from ADS.

The wireless stuff was the most difficult decision. After spending hours searching the web for small cameras and wireless systems, I got pretty tired of seeing dozens of "spy shops" carrying the same tired products at widely varying prices. Polaris made a good impression from the start. Perhaps it's because they position themselves for the 'industrial security' market catering to businesses, and not as a 'spy shop' catering to wannabe private eyes and deranged/snooping stalker types ("Night Vision" is at the bottom of their list, and they don't even carry those spooky clock-radio cameras). From their web site to their phone presentation to the post-sale phone call to double-check the order, I felt pretty good about the way they conducted their business.

Anyhow, here's the hardware, with prices included should you be interested in doing something like this yourself.

Camera	Polaris WP-300C $230	weatherproof camera, "lipstick" form factor, 1/3" CCD, 400 lines, auto white balance and iris/shutter, 2.2 ounces, 150ma at 12 volts
Transmitter	Polaris SJ-2400TX $150	2.4 GHz Audio/Video transmitter, license-free, 1.5 ounces, ~200ma @ 12volts. Polaris claims it works well for RC video projects.
Receiver	Polaris GFR-4004 $170	2.4 GHz Audio/Video Receiver, 5x7 inches, with detachable / replacable antenna, requires 12 volts
Power Supplies		The receiver is powered by the same 12 volt gel-cell and/or lead-acid batteries I use to start my helicopters. The transmitter is powered by ten 270mah ni-cads in a home-built pack.
Recorder	Sony TRV-510 $700	Digital camcorder, uses standard 8mm tapes, has inputs for audio and video from the wireless receiver, a 4" LCD for field viewing, and IEEE 1394 (aka iLink, aka FireWire) so I can put the video onto my computer and the web. Bargain price because it was an "open box special" at a local shop.
Capture	ADS Pyro Digital Video $95	PCI FireWire board, with camcorder cable and Ulead Video Studio software Note: this product sucks. Ditto for ADS tech support. The double images you seen in these videos (and especially in the rest of the videos on my site, where camera vibration is not an issue) is a direct result of this product's inability to properly decode the signal from the camcorder. Their tech support was no help at all - nobody ever answers the phone! I've left messages and never had a call back. If any ADS people are reading this, I'd love to be proven wrong. What's the secret to getting a decent picture out of this thing? Thanks for reading this. I feel a little bit better now!
Head Mounted Display	TBD	<tongue_in_cheek> If you would like to contribute to the telepresent aerobatics fund, please contact me via the link at the bottom of this page. In return for your contribution of $500, you will receive my undying gratitude and a link on this page. Act now, this is a limited time offer. </tongue_in_cheek>

Video camera, receiver, and transmitter

The Polaris equipment arrived January 6th. The only surprise was that the receiver is not the same device pictured on their web site and in their catalog. No big deal though, as it works fine and even (in my humble opinion) looks a little nicer.

I didn't get a chance to start in on this stuff until the 7th. It took about 5 hours (not including dinner) to assemble the battery pack, then design and solder up a wiring harness for the camera, transmitter, and battery pack, plus cord a to power the receiver from a 12v gel-cell. The transmitter has provisions for a microphone, but I haven't bothered with that just yet.

At about 1am I verified that everything worked, then lashed the works to the top of my RC car (HPI RS4 Pro) and took it for a spin around my house. I sat on the couch watching the television the whole time, of course. Between the late hour, the months of planning, and the thrill of all that hard work paying off, I couldn't stop giggling. Click here for an MPEG I recorded the next morning, using my camcorder's display as a "windshield."

The video quality was better than I had expected - at least on par with an average VHS VCR, and definitely better than most of the TV stations we get in this cable-impaired hosuehold. The video files you'll find here are a bit dark around the corners, but I didn't notice that until much later - somehow this doesn't show up on the TV or camcorder screens. The electronics held up beautifully in spite of a few collisions with furniture and walls (oooops). The video signal glitched a bit more than I'd hoped (even when not colliding with big heavy things), but all in all it wasn't too bad.

It was supposed to rain all weekend, but with a surprise bit of good weather on the 9th, I applied all of the video gear to my Concept 30 SRX and headed for the flying field. The camera and transmitter were attached to the left skid, and the battery was attached to the right skid. I used vetwrap to attach the camera and transmitter to a 1"x10" board, with 1/2" latex foam for vibration insulation. This board was fastened to the left skid with zip ties; the battery was fastened to the right skid, again with zip ties, foam, and vetwrap. This balanced reasonably well, and endured 3D flight with nary a slip or a slide.

With the aid of some friends and walkie-talkies, we conducted range tests of the radio control system and the video system working together. Range with the RC antenna collapsed (standard pre-flight range check) was no different than without the video system. At this point my friends extended the radio control antenna and I headed across the field. The radio control system displayed no signs of interference at all, at any point during this test. I'm not sure how far out I walked, but I'm quite sure that it was further away than I let the helicopter get when I'm flying it, so I was satisfied. My friends reported trouble with the video signal at less range than I'd been hoping for, but more on that below.

With the range checks completed, I fired up the engine and took to the air. The good news is, the weight of the video system is negligible, the helicopter felt just as agile as ever, both the camera/transmitter and remained secure throughout the flight, and the RC system was unaffected by the video system. I used FM/PPM to get the best possible measure of radio interference, and was quite happy to see no glitches during the flight, a fact confirmed by my BC-6 battery monitor. My biggest worry about this whole project was that RFI from the video system would compromise the effectiveness of the RC system, so this was a big relief. Helicopters have occasionally demonstrated a voracious appetite for human flesh, so I wasn't about to compromise the control system for the sake of a few minutes of video.

Two problems did show up, though. First, and entirely expected, my Concept's rough running has given all of the helicopter footage a coninuous jitter. I suspect this is due to the combination of 30% nitro and a tuned exhaust, and that I can tame the vibration by reducing the compression. Head shims are on order, and will hopefully arrive before the next weekend does.

Second, the video footage dropped out quite often, particularly during unusual orientations (read: aerobatics). It's also clear that the signal is most prone to dropping out when the video transmitter antenna is on the far side of the helicopter, perhaps because its line-of-sight to the receiver is blocked by the battery pack on the near side of the helicopter.

I will be experimenting with different antenna mounting locations and orientations in an effort to minimize the signal dropouts. It is my hope the the dropouts will be fewer when the antenna is postioned at the extreme rear of the helicopter, with the helicopter itself taking up the smallest possible "slice" of the antenna's radiation pattern.

I'm not sure if this qualifies as a bug or a feature, but the camera's auto white-balance and auto iris features always seem to be playing catch-up with the available light. Drastic changes are evident when the sky enters and leaves the field of view. On the one hand, this probably means that I'm getting better footage than I would otherwise - on the other hand, it's kind of distracting when you're viewing the footage. Too bad the iris and white-balance features aren't adjustable - it might be fun (or at least educational) to experiment with different settings.

I will also be experimenting with placing the receiver antenna directly below the flying area - as opposed to behind the flight line - to boost the reception. If none of the above proves effective enough, I'll look into higher-gain (patch or Yagi) receiver antennae. As a last resort, there's always the option of a HAM license and a stronger transmitter. Stay tuned.

I managed a bit less than ten minutes of flimed flight before the batteries went dead (the extensive range tests described above took a real toll on them). Given all of the interference trouble, I have only been able to pick out a total of perhaps three minutes of presentable footage. The stuff below still has more glitching than I'm really happy with, but a least the maneuvers are recognizable.

Video files! These are all MPEG encoded at 320x240 and 30 frames/second. None include audio because I haven't wired a microphone to the transmitter (at least, not yet).

1. Navigating my house with an electric RC car (3.1 megabytes)
2. The first 30 seconds of helicopter flight (5 megabytes, poor quality as it was encoded on my old computer)
3. Half roll, half-roll tailslide, backwards flight, half pirouette, "blunt" reversal, another half-roll tailslide, nose-in hover. (4.1 megabytes)
4. Half roll, half-roll tailslide, slow flip/stall, blunt, pirouette (3.8 megabytes)
5. Kinerturn (just a little over 2 megabytes)
6. Hovering roll (.8 megabytes)
7. View of flight line and parking lot, then a roll in forward flight (1.1 megabytes)

   Later, with a Futura SE...

8. Loop with single pirouette (2.8 megabytes)
9. Random stuff (6.3 megabytes)
   These files show more glitching than the others, just to illustrate my point. There are a couple of chaos tumbles at the end, but you can hardly recognize them as such because the signal drops so often.

Check back in a week or three (hey, it's ski season, this is not my top priority) and perhaps we'll see how the engine and antenna changes work out.

P.S. Special thanks to Mom and Dad who spotted the deal on the Sony, jumped on it, and got this ball rolling after three or four years of indecision and procrastination on my part!