Apr 25, 2018

Apr - 25 2018 | By

Notifications of new show notes and edits are tweeted at: twitter.com/ddhart.
– They’re tagged with #Zentech.
– When what’s said is unclear to me (or I’m unfamiliar with a topic) I tend to quote (” “) verbatim.
– Editor’s comments are delimited by < >

For a couple of months, the audio of today’s show is here. Recent shows are here.

The intro & outro music was by Pentatonix.

Glenn said there will be a membership drive during the 2nd week of May. There might not be a Zen Tech show on 5-9-18


Both Glenn and Paul were in the studio with guest Jeff Cox.
Today’s show was more conversational than instructive. I tried to capture the highlights.


Besides training to be a KVMR broadcaster, Jeff, like Paul, has an interest in quadcopter drones and the hour was spent talking about them.

Jeff works for Holdrege & Kull, which was acquired by NV5 about 1 year ago.
It’s located at 792 Searls Avenue, Nevada City, CA 95959, (check their webpage for other locations.)
Phone: 530-478-1305
Learn more by going to any of the following websites.
You can contact Jeff here.

Paul started off talking about bugs that have existed in the Intel CPUs since at least about 2007 and possibly as far back as 1997. <The bugs are known as Meltdown & Spectre are were covered the the 1-10-18, 1-24-18 and 1-31-18 shows> The problem affects anything that uses the Intel CPU and is thought to affect the AMD CPUs also.

Linux, Microsoft, and Apple have sent out patches to mitigate the problem but the computer can be slowed up to 15% as a result. The slowdown shouldn’t be noticeable when surfing the internet but will affect video rendering or audio production. Paul said he’ll post more info to the Zen Tech website. It’s not a substantial issue, he said. The danger is that it’s possible at all to exploit the bugs, not that it’s prevalent. Only about 1 in 100 attempts succeed. “It also relies on the fact that you must recently, before you rebooted, have done something that involved secure data”. <There has to be some sensitive data sitting in the CPU’s cache, as I understand it.>

Jeff Cox intoduced himself. He’s been working as a geologist at Holdrege & Kull for about 15 years. Holdrege & Kull has been recently acquired by NV5.

Jeff went on to say that his employer uses drones for aerial survey work. They don’t just take pictures from the drones, they also acquire thermal and multi-spectral data — useful in agriculture and forestry. They also fly LIDAR missions, which uses laser light to find distances and can determine topography in dense forests because the light can go between the tree leaves to reach the ground.

The advantage of using a drone over manned aircraft for LIDAR is that it’s able to fly close to the ground. It can get up to 400 returns per square meter, where the manned aircraft might get only 25. Using LIDAR, there have been many recent discoveries about the Mayan civilization in the jungles of Central America. Jeff’s company had deployed drones to survey sinkholes and landslides in the area, after all of the big rains this year.

But there is still a need for boots on the ground. Land surveyors are used to set markers in the ground at known coordinates, Targets are then attached to the markers that can be seen by the drones. <So they act as reference marks, as I understand it.>

Paul said the 1st drone he bought was the Syma X1 from Amazon. He wanted to get cheap drone, since he was just starting to experiment. It weighs under 1/2 a pound and therefore didn’t need to be registered with the FAA. It has no GPS and it sends no signal back to the operator. It does have a camera with a flash card. Paul discovered that it’s easier to keep track of it at dawn and dusk when the sun is below the horizon. That’s when by its red & green navigation lights are most noticeable.

Paul actually lost it once. He found out that just because the air is still at ground level doesn’t mean it’s still at higher elevations. The wind carried it off but fortunately he had his phone number attached to the it.

Paul said Amazon has the Syma X1 for $29. <This might be the one. There are others listed on that page.>

The guys mentioned a Chinese company called DJI that sells drones with more features. Jeff’s company uses one of their drones to fly the LIDAR unit. He said that drone is $5000 or $6000 for the base unit.

Jeff said that a license is required to operate a drone commercially. You’ll have to study and take A test. There are many rules and regulations to flying a drone commercially, including notifying pilots of other aircraft, e.g. those using hospital heliports that you’ll be operating in their vicinity. The acronym he used was NOTAM — Notice to Airmen.

Jeff mentioned the need to be sure the drone’s batteries are good condition — voltage, temperature and charge. Some have sensors to do that for you. Some drones carry a set of backup batteries for redundancy. If you have professional payloads costing thousands or hundreds of thousands of dollars, you don’t want it falling out of the sky.

Jeff said his company certifies the accuracy of their surveys to 1/10 of a foot. That meets the standards most professional land surveyors would like to achieve.

“The high level of accuracy possible with these quadcopters is achieved using a Russian navigation system called GLONASS“, Paul said.

Glenn thanked supporters of KVMR. If you want to become a member please call the business office at 530-265-9073.

Paul mentioned that the Falcon space missions by Spacex have something in common with the operation of drones — the autonomous robotic navigation systems that bring the booster rockets back to the ground.

The only phone call came from Ward. He commented that high school students went down to Texas for final competition in robotics and they did pretty well, though they didn’t win. There were teams from all over the world including Israel where robotics is part of the curriculum. And there was a heavy presence of defense contractors. If you want to see drones fly locally, go to the Gilmore School in the mornings. Some of the drones are able to come back to the same spot without using GPS: they process visual information and recognize the location.

Paul’s not very happy with the militarization of drones. He said there’s been talk of having treaties to prevent drones from being used as antipersonnel devices.

Last Updated 11:22 AM 4-26-2018

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