Archive
UAV (drone) forensic analysis presentation available on YouTube
DJI Phantom 3 Log Analysis Tool
Rowland Johnson developed an excellent tool, DatCon, for analyzing DJI Phantom 3 log files in Java. I arranged to have it ported to Python because I am far more adept with Python and wanted something that I could extend to support newer file formats and potentially other UAVs.
The result can be found here:
https://github.com/dkovar/uav-log-analysis
It is my hope that others will build on this, adding support for other DJI products as well as adding visualization capabilities.
Feedback, suggestions, etc are always welcome.
UAV Forensics – version 2
Working with Greg Dominguez and Cindy Murphy, we updated my UAV Forensics presentation from last year to address the Phantom P3, it’s additional data sources, some new tools for analyzing data, and our first pass at JTAG analysis.
Greg and I gave the presentation at Techno Security in June and a PDF version is attached here: UAV Forensics -TS16-final distribution
Public Agency Operations and Part 107
After consulting with a UAV lawyer and an FAA representative, I believe that:
- Public Agencies (PAs) still have to operate under a COA
- PAs can also operate non-Public Agency Operations (PAOs) under Part 107.
See pages 61-68 of the Rule for details
If a PA wishes to examine the roof of the court house for hail damage, a Part 107 operator working for the PA can perform the task.
If a PA wishes to conduct a SAR mission, or fly a UAV in support of fire fighting operations, they need a COA or to contract with a 333 exempt operator with the appropriate COA.
FAA Position on Contracted UAS Operations by Public Agencies
[The following was written in my role as the Advocacy Director for the National Association of Search and Rescue. A PDF version is available here – Public Agency SUAS-final.]
This is an interpretation of information in the Advisory Circular 00-1.1A “Public Aircraft Operations” and refers to Title 14 of the Code of Federal Regulations (14 CFR); and Title 49 U.S.C. §§ 40102(a)(41) and 40125.
Public agencies and civil operators are encouraged to retain their own attorney to review this interpretation.
After consultation with a UAV lawyer and their FAA consultant, we believe that civil aircraft operators may fly UAVs in support of government entities (public agencies) if the following conditions are met:
- The public agency has a COA
- A contract exists between the public agency and the civil aircraft operator
- A one time declaration is filed with the FAA by the public agency
- The mission(s) flown are purely public service
- The public agency makes a determination before each mission that the mission is public serving
If these conditions are met, any civil operator regardless of certifications may operate a UAV in support of the public entity under the requirements set forth by the public entity and its COA.
CAUTIONARY NOTE: The civil operator is not required to have a 333, or to have passed the certification described in (proposed) Part 107 in these circumstances. However, the agency can and should require a 333 or the certification described in Part 107, as a requirement of the contract with the civil operator.”
It is extremely important to note that:
- The public agency must have a COA.
- This is transferring almost all risk, responsibility, and liability for certification, experience, training, etc. from the FAA to the public agency.
- There must be a contract in place between the public agency and the civil operator (it is recommended that the contract include a requirement for the civil operator to hold a 333 or part 107)
- The declaration names a specific government official and contract that covers the relationship
It is of vital importance that the public agency maintains control of the operator of the UAV and of the missions. The liability completely falls on the public agency. There is great risk if an agency enters into this relationship without a complete understanding of the risks associated with it.
This is spelled out in more detail in Advisory Circular 00-1.1A “Public Aircraft Operations” and refers to Title 14 of the Code of Federal Regulations (14 CFR); and Title 49 U.S.C. §§ 40102(a)(41) and 40125.
[An FAA presentation on this topic is available here – FAA Public Aircraft Presentation.]
ASTM Efforts on Small UAS
Quoting from a widely distributed email. I work on one UAS ASTM effort to type Small UAS. Here are their other efforts. Of particular interest is F2908 “Specification for Aircraft Flight Manual (AFM) for a Small Unmanned Aircraft System (sUAS).”
Small UAS Operations
ASTM International Committee F38 on Unmanned Aircraft Systems has recently approved seven new standards that cover all major facets of small unmanned aircraft systems operations, including design, construction, operation and maintenance requirements.
The following seven new ASTM standards, written for all sUAS that are permitted to operate over a defined area and in airspace defined by a nation’s governing aviation authority, have now been approved by F38:
F2908, Specification for Aircraft Flight Manual (AFM) for a Small Unmanned Aircraft System (sUAS). F2908 defines minimum requirements for the aircraft flight manual, which provides guidance to owners, mechanics, pilots, crew members, airports, regulatory officials and aircraft and component manufacturers who perform or provide oversight of sUAS flight operations.
F2909, Practice for Maintenance and Continued Airworthiness of Small Unmanned Aircraft Systems (sUAS). F2909 establishes a practice for the maintenance and continued airworthiness of sUAS. Requirements for continued airworthiness, inspections, maintenance and repairs/alterations are included.
F2910, Specification for Design and Construction of a Small Unmanned Aircraft System (sUAS). F2910 defines the design, construction and test requirements for sUAS. In addition to general requirements, F2910 covers requirements for structure, propulsion, propellers, fuel and oil systems, cooling, documentation and other key areas.
F2911, Practice for Production Acceptance of Small Unmanned Aircraft System (sUAS). F2911 defines production acceptance requirements for sUAS. Requirements covered include several aspects of production, system level production acceptance, quality assurance and documentation.
F3002, Specification for Design of the Command and Control System for Small Unmanned Aircraft Systems (sUAS). F3002 provides a consensus standard in support of an application to a nation’s governing aviation authority to operate an sUAS for commercial or public use. The standard focuses on command and control (C2) links, including a diagram of a C2 system and general requirements for C2 system components.
F3003, Specification for Quality Assurance of a Small Unmanned Aircraft System (sUAS). F3003 defines quality assurance requirements for design, manufacture and production of small unmanned aircraft systems. Guidance is given to sUAS manufacturers for the development of a quality assurance program.
F3005, Specification for Batteries for Use in Small Unmanned Aircraft Systems (sUAS). F3005 defines requirements for battery cells used in sUAS. Mechanical design and safety, and electrical design battery maintenance are primary battery-related areas that are covered.
“The introduction of these standards developed by F38 will help to provide a safe and appropriate path for near-term routine sUAS operations in airspace systems of the United States and other countries,” says Theodore Wierzbanowski, chairman F38.
Committee F38 encourages participation in its standards developing activities. “The user community for these standards is vast,” says Wierzbanowski. “Feedback on what works and what doesn’t during these early stages of sUAS operation is critical.”
F2908 is under the jurisdiction of F38.03 on Personnel Training, Qualification and Certification, and F2909 was developed by F38.02 on Flight Operations. The other five new standards are under the jurisdiction of F38.01 on Airworthiness.
To purchase ASTM standards, visit www.astm.org and search by the standard designation, or contact ASTM Customer Relations (phone: 877-909-ASTM; sales@astm.org).
CONTACT Technical Information: Theodore J. Wierzbanowski • Punta Gorda, Fla. • Phone: 626-429-8864 | ASTM Staff: Stephen Mawn • Phone: 610-832-9726
Position Papers – UAS Operations in Support of Search and Rescue
UAS, unmanned aerial systems, can play a significant role in search and rescue (SAR) operations. There are a number of hurdles to deploying these assets successfully. In my role as advocacy director for the National Association of Search and Rescue (NASAR) I’ve written position papers to address two of the hurdles:
- UAS deployment in support of SAR (and other disaster response incidents) requires professional UAS operators. At the present time, that means that all UAS operations must be performed under a valid COA either by public agencies or by Section 333 exempt operators. I wrote a paper for NASAR explaining this position and how public agencies and SAR volunteers can fly in support of SAR missions while complying with FAA policy/rules/guidelines.Here is the NASAR announcement which includes a link to the paper.
- Current FAA policy places three significant restrictions on UAS operations that make deployments extremely difficult and very ineffective:
- The operator must issue a NOTAM 72 hours before flying. (SAR is an emergency. UAS assets are extremely helpful in the early stages. Search is an emergency.)
- The operator must fly at or below 200 feet. (Imaging wide swaths of the area, operating in hilly or mountainous terrain, or establishing a communications relay with wide area coverage, requires higher altitudes.)
- The operator must not fly any closer than 500 feet to non-participating individuals or property. (Search subjects do not go missing in areas with zero population and no structures.)
To address these issues, Jason Kamdar and I wrote a proposal for a “First Responder COA (FRCOA)” to submit to the FAA. The document can be found here and the NASAR announcement about the paper and other related activity is here.
A Falling DJI Phantom Might, or Might Not, Crush Your Skull
The title is intentionally provoking. Too many public comments are similar to “A falling drone will give you a bump on the head”. In fact, there is a reasonable chance it will kill you. Which of these is actually true? We simply do not know and some formal experiments are required before claims are made either way. So my point is not really that they may kill you, rather it is that we need good data.
I’d like to thank the members of a particular Facebook group for engaging in a spirited discussion that helped me refine this post. It was far too provocative in the early draft and I am certain that it still is for some.
The theoretical analysis follows, and it ignores a lot of variables. These calculations are a starting point and represent the “worst case scenario”. With a lot of additional work, we could add other constraints and end up with a probability estimate of damage from a direct impact.
Weight of a DJI Phantom – 1242g (2.73 lbs)
Altitude at time of failure – 61m (200 feet)
Force required to crush a human skull – 2,300N (Journal of Neurosurgery: Pediatrics)
Let’s plug those numbers into a calculator:
7173N of force. Almost three times the force required to crush a human skull.
Even from half that height, 100 feet, a falling Phantom would generate 3527N, still enough to crush your skull. At 65 feet you might survive the impact as the force is down to 2351N.
There are a lot of variables that I did not account for – drag, impact angle, elasticity in the body and the drone…. Real experiments need to be performed.
UAVs in SAR – Deployment and Effectiveness
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.
Questions:
I wanted to answer two questions:
- How effective is a UAV when searching an area with trees?
- 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.)
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.
Soybeans
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?
Conclusion:
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.
What Can a Drone Actually “See”?
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.
Experiment:
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.
Conclusions:
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.
Questions:
- 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?
Closing:
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.
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Integriography: A Journal of Broken Locks, Ethics, and Computer Forensics 