Archive for the ‘UAVs’ Category

UAVs in SAR – Deployment and Effectiveness

August 23, 2015 6 comments

In an earlier post I wrote: “I think the search & rescue community should do a lot more work on designing and performing experiments with UAVs. Vendors and sales outlets keep touting their UAVs as being “good for search & rescue” without providing any data to support this claim, and often without really understanding SAR, SAR missions, and the challenges we face. (More on this in my upcoming presentation for NAASIC in Reno in September.)”

This is even more important when we consider what are appropriate missions for UAVs and how to deploy them.

I conducted two very quick experiments to illustrate two of the challenges we face. I intend to develop more formal experiments and welcome others who are interested in assisting with this effort.


I wanted to answer two questions:

  1. How effective is a UAV when searching an area with trees?
  2. How effective is a UAV when searching for clues in a soybean field?

Both of these are simple examples of SAR problems you can adapt to your own operational area.

tl;dr – You need to be down very low when searching near trees and finding an unresponsive subject in a soybean field with an optical sensor is very tough.

Searching Near Trees:

If this was your search area, and if you were searching for an uncooperative or unresponsive subject (someone who isn’t going to come investigate the noise of the UAV), how would you plan your mission? How would you execute it? How long would it take? How effective would you be? (This was taken at 200 feet by a Phantom Vision 2+. The subject is currently in the frame.)

PV2+ 200 feet

Ok, if the subject were standing under a tree in this small area, what would you be able to see? (There are a lot of variables here – height of branches, folliage on or off, distance from subject, subject’s distance from the trunk, …. This is just an example.)

Distance from the UAV to the subject was less than 50 feet in all images.

At the subject’s altitude:


At about a 30 degree angle:


50 degrees. The subject’s legs are barely visible due to the contrast between his blue jeans and the green background. (And, if you were looking at this on a mobile device, what would you really be able to see?)


70 degrees or so. The subject is not visible.


Conclusion – you need to get under the level of the tree branches to search around trees for an unresponsive subject. This will increase your time required to search while diminishing your ability to control the UAV at long ranges.


I live, and search, in Illinois. Lots of corn, lots of soybeans. Searching for anyone in a corn field when the corn is above your head is tough. We’ll come back to that one later. Soybeans get to a few feet tall. Walking through soybean fields is … annoying … but you can certainly see a lot more. If the subject is standing up you can just walk to the edge of the field and say “Hey, there they are!” But, what if they are unresponsive and down?

Again, 50 feet up with a DJI Phantom Vision 2+. The subject dropped their high visibility orange shirt, a clue! We can see it easily on the edge of the field.


But, what if they dropped it in the field? Since you know it is in the frame, and since it is right next to the pilot, you can probably see it. If you were looking at images from 100 acres of soybeans how confident are you that you’d see this clue, particularly on a small screen?



If you are using a normal consumer UAV to search for an unresponsive subject in an area with significant vegetation your probability of detection may be rather low.

Categories: SAR, UAVs Tags: ,

What Can a Drone Actually “See”?

August 23, 2015 2 comments

I think the UAV industry in general and the search & rescue community in specific should do a lot more work on designing and performing experiments with UAVs. Vendors and sales outlets keep touting their UAVs as being “good for search & rescue” without providing any data to support this claim, and often without really understanding SAR, SAR missions, and the challenges we face. (More on this in my upcoming presentation for NAASIC in Reno in September.) On the privacy side, people claim “he couldn’t see anything at 200 feet with that drone.” or the opposite position without sharing any data to support these claims.

Since I am an engineer, I like to gather data to support conclusions. And, for similar reasons, I usually form a hypothesis prior to conducting an experiment. Full disclosure – the data did not support my hypothesis. I’ll explain at the end of this post.

For the tl;dr folk – you cannot see much detail in a stock Phantom 2 Vision+ image when taken more than 50 feet above the subject.


This experiment was conducted with a stock DJI Phantom 2 Vision+. The lens specifications, according to DJI, are:

  • Sensor Size – 1/2.3″
  • Effective Pixels – 14 Megapixels
  • Resolution – 4384×3288
  • Recording FOV -110° / 85°

I had the camera set to use the “large” photo size and thus the full resolution.

The items in the frame are:

  • A black Pelican case
  • A human male wearing blue jeans and a reddish t-shirt
  • A high visibility orange long sleeve thermal shirt
  • A light blue t-shirt
  • A white board with black writing on it

The sky was overcast and the winds were between 5 and 15mph out of the south east. I took the Phantom up to 25, 50, 100, 150, 200, 250, and 300 feet, +/- 3 feet as reported by DJI’s Vision app. At each altitude I took a single photograph. After landing, I used Photoshop to zoom in to approximately the same area in each image.


In the raw images viewed natively without any zoom:

  • It is hard to find any identifying details of a human in the image above 50 feet.
  • At 200 feet it would be hard to identify the human if you did not know what you are looking at.

Using the zoom tool in Photoshop:

  • Detail is hard to discern at 100 feet and very difficult past 100 feet
  • Given the subject’s pose you can determine that there is a human in the frame up to 300 feet.


  • If you thought a drone would be invading your privacy when flown at 200 feet do you still feel this way after looking at these images?
  • If you want to use a drone to search for missing people, do these images help you determine your mission parameters and effectiveness?


And my hypothesis? I thought more detail would be available further up. Glad I’m conducting experiments.

Image analysis is not my forte. If you have additional observations, please comment or share them with me directly and I’ll get them included.

25 feet

PV2+ 25 feet PV2+ 25 feet zoom

50 feet

PV2+ 50 feet PV2+ 50 feet zoom

100 feet

PV2+ 100 feet PV2+ 100 feet zoom

150 feet

PV2+ 150 feet PV2+ 150 feet zoom

200 feet

PV2+ 200 feet PV2+ 200 feet zoom

250 feet

PV2+ 250 feet PV2+ 250 feet zoom

300 feet

PV2+ 300 feet PV2+ 300 feet zoom

Categories: SAR, UAVs Tags: ,

Recorded presentation of UAV forensic analysis

I’ve been giving a presentation on the fundamentals of UAV forensics for several months, primarily for law enforcement and for other cyber security people. The presentation was recorded last month and is available on line.

50 minutes long but probably worth watching if you are interested in such things.

Categories: Computer forensics, UAVs

Using UAVs for conducting post-tornado damage assessments

On July 17th, 2015, we were asked by the Tazewell County Emergency Management Agency to fly a UAV mission to collect aerial imagery to be used for damage assessment and storm severity determination. Within an hour of the request, we were on scene. All of the imagery was collected within two hours and Pekin’s GIS department processed and hosted the imagery within two additional hours. Call out to online imagery was five hours. Additional area to be covered would not have significantly impacted the total time required.

The ability to perform rapid deployment, collection and analysis workflows is crucial in emergency management settings. Our attention to processes, procedures, training, and relationships enabled us to perform this work efficiently and safely.

The swipe map version of the imagery can be found here.


Categories: UAVs

The flip side of drone privacy – personal details of UAV operators exposed

People have been registering domain names for years and many years ago someone realized that being able to anonymously register a domain name might be a good idea. There is now a proxy system in place that enables the owner to provide their real contact information but to hide it from casual observers. And there is a recent fight to keep this system in place to help prevent web site owners from being doxed and swatted.

The FAA probably should have considered doing something similar before requiring N numbers for all UAVs. Huh? Unless you are a pilot, or have gone through a Section 333 petition you probably didn’t know that most aircraft require an N number. That number is prominently displayed somewhere on the aircraft and it associates the aircraft with a specific person or organization for all the world to see.

So what is the privacy issue? “All the world to see.” Try this:

  1. Go to the FAA N number query site –
  2. Click on “Make / Model”
  3. Enter “DJI” in the “Manufacturer Name” field
  4. Find an entry where the name field is just “DJI”
  5. Click on one of the states listed in the second column

There is potentially a lot of personal information there, particularly if you didn’t know what was going to happen when you filed for your N number. When I applied for a 333 exemption, I did so as a company and the company’s address is not my home address. Sure, someone can still work their way back to my physical location but why make it easy?

Two take home points:

  1. If you can, file for your N number using an address that is not your home physical address
  2. The FAA clearly didn’t think ahead when requiring N numbers for UAVs. Let’s guess that there will be 500,000 UAVs flying in the US within five years. That is a lot of paperwork to file for all those N numbers, and a lot of personal data available to innocent or malicious people

Maybe the FAA should take a tip from the DNS world and provide a proxy service for UAV operators? I agree that the data should be collected (and this may not be a majority opinion) but I also feel that it should be somewhat protected.

Categories: UAVs

Tips on starting a UAV/drone based business

We were recently interviewed and asked to talk about how we got into UAVs and what tips we could share with others who are interested in doing so. It came out pretty well.

Categories: UAVs

A quick UAV point of view on the impact of too much rain on soy and corn.

I am not a farmer but I’ve been living among them for years now. Some of my best friends are farmers, truckers, and mechanics and conversations naturally turn to farming and crops. I’ve also been getting heavily involved in precision agriculture through UAV/drone imagery and data collection so looking at crops and taking pictures of them is becoming more a part of my daily life.

Rather than produce imagery for a farmer today, I thought I’d produce some imagery for my friends to help communicate what “too much rain” looks like to a farmer.



That is soy, or should be soy, in the foreground. It is currently approximating a marsh. Corn is on the other side of the road and you can start to see the scale of the impact, and why getting drainage right is so important.



Again, soy in the foreground but less flooded. Some pretty healthy corn and then more corn impacted by the water. This photograph also demonstrates the value of aerial imagery – the field in the distance is not visible from ground level without driving through the standing corn closer in.

Categories: UAVs

What are the most popular drones for commercial use? Let’s ask the Section 333 data.

June 30, 2015 3 comments

Last week we took a look at the FAA Section 333 exemption grant data to see what states had the most activity, how long the FAA took to issue grants, and what purposes were given for flying a UAV commercially. This week we want to explore what vendors and UAV models are most popular with commercial UAV operators.

Keep in mind that this data only covers organizations that chose to file a 333 exemption. Also, there is some lack of clarity in the models. For example, the Skywalker Flying Wing appears in the data. I believe that this represents someone doing a custom build using the Skywalker as a base.

We’ll answer the following questions:

  • What is the most popular UAV model used by commercial operators with a 333 exemption?
  • For vendors that have more than one model, which model is most popular?
  • Where are those vendors located?

If you have additional questions that might be answered by analysis of this data set, please drop us a line and we’ll try to get it answered. Also, if anyone is interested in funding additional research, we’d love to collect and analyze similar data sets from other countries.

So what is the most popular UAV model used by commercial operators with a 333 exemption? The DJI Phantom 2V+.

UAV model popularity-cropped

DJI holds the top five spots and eight of the top ten spots. (This chart is truncated, the full chart is available at the end of this post.)

Next, for vendors that have more than one model, which model is most popular?

UAV model popularity-multiple models

DJI’s most popular model is the Phantom Vision 2+, Sensefly’s eBee is their most popular model, and 3DR Iris+ leads their line. An example of the type of follow on question that comes out of this analysis is this – Why is the Altavian Nova F6500 more popular than their R8400?

Finally, where are those vendors located?

UAV vendor countries


As we have been hearing for months, DJI dominates the US market for UAVs. But US vendors out number all other vendors combined. I wonder what that will look like in a year’s time? Two year’s time? I do not think that the market can sustain 50+ UAV vendors.

What impact will regulation have on these figures? What vendors will be able to successfully integrate transponders, for example, into their product line.

As operators start generating revenue, will they continue to use consumer grade UAVs or will they move to purpose built UAVs with more professional features?

Watching the vendor space mature and settle out will be very interesting.

Full chart of models listed in Section 333 grants:

UAV model popularity

Categories: UAVs

Analysis of FAA 333 exemption grants, it isn’t all about photography

June 22, 2015 15 comments

There is a lot of uncertainty in the US UAV market due to lack of data. We do not have accurate sales data, number of hours flown, number of incidents, or even a good definition of what a UAV incident is. However, there is one really good UAV related dataset: Authorizations Granted Via Section 333 Exemptions. This is the FAA’s list of exemptions granted to allow commercial UAV operations.

Let’s ask some simple questions of the data, leaving the best for last. (If you don’t want to read the whole thing, please do pay attention to the last question.)

  1. How many petitions/exemptions by state?
  2. What was elapsed time between filing of petition and granting of exemption?
  3. How many petitions were there for each industry/purpose?

Before going forward please understand this – this post is not in any way a comment on the legality or appropriateness of the 333 process and it does not in any way imply that commercial operations without a 333 are in some way illegal or “worse” than operations with a 333 exemption.

Read more…

Categories: UAVs

Precision guided counter-UAV solutions, a thought piece

April 19, 2015 2 comments

Most counter-UAV techniques are illegal or very closely regulated outside of a war zone. The proliferation of consumer and commercial UAVs is prompting people to consider ways to disable them or take them down outside war zones. So far, we have seen shotguns, brooms and even kangaroos. How about some more precise options?

What follows is a thought exercise. Jamming, firing weapons indiscriminately, and even taking down a UAV with a net are all likely to be illegal wherever you might be reading this.


Most UAVs are controlled by a pilot using a radio transmitter or by a ground control system that instructs the UAV to fly to a particular set of waypoints. It is possible to jam the control signal, monitor the data channel, and even hijack the UAV. (A subject for another post.) This activity is certainly illegal.

A simple physical approach:

Acquiring and targeting a small UAV in motion with the Mark 1 human eyeball is tough. Attempting to shoot it down with a normal firearm is harder still. Doing so would violate several fundamentals of firearm safety:

  • Always keep the muzzle pointed in a safe direction
  • Be sure of your target and what’s beyond it.

If you really want to physically take down a UAV using a projectile weapon, consider using a net gun or a paintball rifle. (More on that later.)

Automatic targeting:

Let us put aside “how to bring down the UAV” for a moment and address UAV detection. There are commercial solutions in this space and interested parties should explore those options for definitive, professional solutions. For the sake of this exercise, lets consider something like the Bluetooth Sniper Rifle.

Many consumer UAVs use 2.4GHz for command & control or data links. Such a “rifle” should detect a UAV using 2.4GHz at long range. Mount such a device on a tripod with a gimbal driven by a system that can point the detector in the direction of maximum signal strength. (Exercise left to the reader, as my professors used to say.) This provides a bearing and elevation from your location to the device you are targeting. You’ll have to spray the air space with rounds as you don’t have range information to provide a precise targeting solution but you could have the paintball gun fire in a pattern to place shots around the target. A few paintballs in the rotors should do the trick.

Now, tie two or more of these targeting systems together and you’ll have bearing, elevation, and range to the target. If you know the ballistics of your paintball rifle, you could probably place some pretty precise shots rather than spraying the air. It has been awhile since I used a paintball rifle but I recall that figuring out the trajectory of a paintball round was quite difficult.

[If anyone wants to try building this, please let me know and I’ll help.]

TrackingPoint – a precision solution:

TrackingPoint has a commercial solution for calculating targeting solutions for rifles, what they call “precision guided firearms”. Their solution uses a human to acquire and mark the target and then fire the round. Once the human marks a target, a computer tied into the rifle calculates the appropriate solution and guides the human to make the precise shot.

So the system takes targeting information in electronic form and uses it to provide a targeting solution. Can’t we take the targeting data from something similar to what we postulated above and use it to guide the human? I imagine so. (I asked TrackingPoint about this possibility and received no response.)

Keep the human on the trigger and use frangible, rubber, or other non-lethal rounds. You may have a long distance, precise, counter-UAV solution.

Categories: UAVs Tags: ,