Tag Archives: Response

Using Computer Vision to Analyze Aerial Big Data from UAVs During Disasters

Recent scientific research has shown that aerial imagery captured during a single 20-minute UAV flight can take more than half-a-day to analyze. We flew several dozen flights during the World Bank’s humanitarian UAV mission in response to Cyclone Pam earlier this year. The imagery we captured would’ve taken a single expert analyst a minimum 20 full-time workdays to make sense of. In other words, aerial imagery is already a Big Data problem. So my team and I are using human computing (crowdsourcing), machine computing (artificial intelligence) and computer vision to make sense of this new Big Data source.

For example, we recently teamed up with the University of Southampton and EPFL to analyze aerial imagery of the devastation caused by Cyclone Pam in Vanuatu. The purpose of this research is to generate timely answers. Aid groups want more than high-resolution aerial images of disaster-affected areas, they want answers; answers like the number and location of damaged buildings, the number and location of displaced peoples, and which roads are still useable for the delivery of aid, for example. Simply handing over the imagery is not good enough. As demonstrated in my new book, Digital Humanitarians, both aid and development organizations are already overwhelmed by the vast volume and velocity of Big Data generated during and post-disasters. Adding yet another source, Big Aerial Data, may be pointless since these organizations may simply not have the time or capacity to make sense of this new data let alone integrate the results with their other datasets.

We therefore analyzed the crowdsourced results from the deployment of our MicroMappers platform following Cyclone Pam to determine whether those results could be used to train algorithms to automatically detect disaster damage in future disasters in Vanuatu. During this MicroMappers deployment, digital volunteers analyzed over 3,000 high-resolution oblique aerial images, tracing houses that were fully destroyed, partially damaged and largely intact. My colleague Ferda Ofli and I teamed up with Nicolas Rey (a graduate student from EPFL who interned with us over the summer) to explore whether these traces could be used to train our algorithms. The results below were written with Ferda and Nicolas. Our research is not just an academic exercise. Vanuatu is the most disaster-prone country in the world. What’s more, this year’s El Niño is expected to be one of the strongest in half-a-century.

Screen Shot 2015-10-11 at 6.11.04 PM

According to the crowdsourced results, 1,145 of the high-resolution images did not contain any buildings. Above is a simple histogram depicting the number of buildings per image. The aerial images of Vanuatu are very heterogeneous, and vary not only in diversity of features they exhibit but also in the angle of view and the altitude at which the pictures were taken. While the vast majority of the images are oblique, some are almost nadir images, and some were taken very close to the ground or even before take off.

Screen Shot 2015-10-11 at 6.45.15 PM

The heterogeneity of our dataset of images makes the automated analysis of this imagery a lot more difficult. Furthermore, buildings that are under construction, of which there are many in our dataset, represent a major difficulty because they look very similar to damaged buildings. Our first task thus focused on training our algorithms to determine whether or not any given aerial image shows some kind of building. This is an important task given that more than ~30% of the images in our dataset do not contain buildings. As such, if we can develop an accurate algorithm to automatically filter out these irrelevant images (like the “noise” below), this will allows us focus the crowdsourced analysis of relevant images only.


While our results are purely preliminary, we are still pleased with our findings thus far. We’ve been able to train our algorithms to determine whether or not an aerial image includes a building with just over 90% accuracy at the tile level. More specifically, our algorithms were able to recognize and filter out 60% of the images that do not contain any buildings (recall rate), and only 10% of the images that contain buildings were mistakingly discarded (precision rate of 90%). The example below is an example. There are still quite a number of major challenges, however, so we want to be sure not to over-promise anything at this stage. In terms of next steps, we would like to explore whether our computer vision algorithms can distinguish between destroyed an intact buildings.

Screen Shot 2015-10-11 at 6.57.05 PMScreen Shot 2015-10-11 at 6.57.15 PM

The UAVs we were flying in Vanuatu required that we landed them in order to get access to the collected imagery. Increasingly, newer UAVs offer the option of broadcasting the aerial images and videos back to base in real time. DJI’s new Phantom 3 UAV (pictured below), for example, allows you to broadcast your live aerial video feed directly to YouTube (assuming you have connectivity). There’s absolutely no doubt that this is where the UAV industry is headed; towards real-time data collection and analysis. In terms of humanitarian applications, and search and rescue, having the data-analysis carried out in real-time is preferable.


This explains why my team and I recently teamed up with Elliot Salisbury & Sarvapali Ramchurn from the University of Southampton to crowdsource the analysis of live aerial video footage of disaster zones and to combine this crowdsourcing with (hopefully) near real-time machine learning and automated feature detection. In other words, as digital volunteers are busy tagging disaster damage in video footage, we want our algorithms to learn from these volunteers in real-time. That is, we’d like the algorithms to learn what disaster damage looks like so they can automatically identify any remaining disaster damage in a given aerial video.

So we recently carried out a MicroMappers test-deployment using aerial videos from the humanitarian UAV mission to Vanuatu. Close to 100 digital volunteers participated in this deployment. Their task? To click on any parts of the videos that show disaster damage. And whenever 80% or more of these volunteers clicked on the same areas, we would automatically highlight these areas to provide near-real time feedback to the UAV pilot and humanitarian teams.

At one point during the simulations, we had some 30 digital volunteers clicking on areal videos at the same time, resulting in an average of 12 clicks per second for more than 5 minutes. In fact, we collectively clicked on the videos a total of 49,706 times! This provided more than enough real-time data for MicroMappers to act as a human-intelligence sensor for disaster damage assessments. In terms of accuracy, we had about 87% accuracy with the collective clicks. Here’s how the simulations looked like to the UAV pilots as we were all clicking away:

Thanks to all this clicking, we can export only the most important and relevant parts of the video footage while the UAV is still flying. These snippets, such as this one and this one, can then be pushed to MicroMappers for additional verification. These animations are small and quick, and reduce a long aerial video down to just the most important footage. We’re now analyzing the areas that were tagged in order to determine whether we can use this data to train our algorithms accordingly. Again, this is far more than just an academic curiosity. If we can develop robust algorithms during the next few months, we’ll be ready to use them effectively during the next Typhoon season in the Pacific.

In closing, big thanks to my team at QCRI for translating my vision of Micro-Mappers into reality and for trusting me well over a year ago when I said we needed to extend our work to aerial imagery. All of the above research would simply not have been possible without MicroMappers existing. Big thanks as well to our excellent partners at EPFL and Southampton for sharing our vision and for their hard work on our joint projects. Last but certainly not least, sincerest thanks to digital volunteers from SBTF and beyond for participating in these digital humanitarian deployments.

A Force for Good: How Digital Jedis are Responding to the Nepal Earthquake (Updated)

Digital Humanitarians are responding in full force to the devastating earthquake that struck Nepal. Information sharing and coordination is taking place online via CrisisMappers and on multiple dedicated Skype chats. The Standby Task Force (SBTF), Humanitarian OpenStreetMap (HOT) and others from the Digital Humanitarian Network (DHN) have also deployed in response to the tragedy. This blog post provides a quick summary of some of these digital humanitarian efforts along with what’s coming in terms of new deployments.

Update: A list of Crisis Maps for Nepal is available below.

Credit: http://www.thestar.com/content/dam/thestar/uploads/2015/4/26/nepal2.jpg

At the request of the UN Office for the Coordination of Humanitarian Affairs (OCHA), the SBTF is using QCRI’s MicroMappers platform to crowdsource the analysis of tweets and mainstream media (the latter via GDELT) to rapidly 1) assess disaster damage & needs; and 2) Identify where humanitarian groups are deploying (3W’s). The MicroMappers CrisisMaps are already live and publicly available below (simply click on the maps to open live version). Both Crisis Maps are being updated hourly (at times every 15 minutes). Note that MicroMappers also uses both crowdsourcing and Artificial Intelligence (AIDR).

Update: More than 1,200 Digital Jedis have used MicroMappers to sift through a staggering 35,000 images and 7,000 tweets! This has so far resulted in 300+ relevant pictures of disaster damage displayed on the Image Crisis Map and over 100 relevant disaster tweets on the Tweet Crisis Map.

Live CrisisMap of pictures from both Twitter and Mainstream Media showing disaster damage:

MM Nepal Earthquake ImageMap

Live CrisisMap of Urgent Needs, Damage and Response Efforts posted on Twitter:

MM Nepal Earthquake TweetMap

Note: the outstanding Kathmandu Living Labs (KLL) team have also launched an Ushahidi Crisis Map in collaboration with the Nepal Red Cross. We’ve already invited invited KLL to take all of the MicroMappers data and add it to their crisis map. Supporting local efforts is absolutely key.


The Humanitarian UAV Network (UAViators) has also been activated to identify, mobilize and coordinate UAV assets & teams. Several professional UAV teams are already on their way to Kathmandu. The UAV pilots will be producing high resolution nadir imagery, oblique imagery and 3D point clouds. UAViators will be pushing this imagery to both HOT and MicroMappers for rapid crowdsourced analysis (just like was done with the aerial imagery from Vanuatu post Cyclone Pam, more on that here). A leading UAV manufacturer is also donating several UAVs to UAViators for use in Nepal. These UAVs will be sent to KLL to support their efforts. In the meantime, DigitalGlobePlanet Labs and SkyBox are each sharing their satellite imagery with CrisisMappers, HOT and others in the Digital Humanitarian Network.

There are several other efforts going on, so the above is certainly not a complete list but simply reflect those digital humanitarian efforts that I am involved in or most familiar with. If you know of other major efforts, then please feel free to post them in the comments section. Thank you. More on the state of the art in digital humanitarian action in my new book, Digital Humanitarians.

List of Nepal Crisis Maps

Please add to the list below by posting new links in this Google Spreadsheet. Also, someone should really create 1 map that pulls from each of the listed maps.

Code for Nepal Casualty Crisis Map:

DigitalGlobe Crowdsourced Damage Assessment Map:

Disaster OpenRouteService Map for Nepal:

ESRI Damage Assessment Map:

Harvard WorldMap Tweets of Nepal:

Humanitarian OpenStreetMap Nepal:

Kathmandu Living Labs Crowdsourced Crisis Map: http://www.kathmandulivinglabs.org/earthquake

MicroMappers Disaster Image Map of Damage:

MicroMappers Disaster Damage Tweet Map of Needs:

NepalQuake Status Map:

UAViators Crisis Map of Damage from Aerial Pics/Vids:
http://uaviators.org/map (takes a while to load)

Visions SDSU Tweet Crisis Map of Nepal:

Humanitarian UAVs Fly in China After Earthquake (updated)

A 6.1 magnitude earthquake struck Ludian County in Yunnan, China earlier this month. Some 600 people lost their lives; over 2,400 were injured and another 200,000 were forced to relocate. In terms of infrastructure damage, about 30,000 buildings were damaged and more than 12,000 homes collapsed. To rapidly search for survivors and assess this damage, responders in China turned to DJI’s office in Hong Kong. DJI is one of leading manufacturers of commercial UAVs in the world.

Rescuers search for survivors as they walk among debris of collapsed buildings after an earthquake hit Longtoushan township of Ludian county

DJI’s team of pilots worked directly with the China Association for Disaster and Emergency Response Medicine (CADERM). According to DJI, “This was the first time [the country] used [UAVs] in its relief efforts and as a result many of the cooperating agencies and bodies working on site have approached us for training / using UAS technology in the future […].” DJI flew two types of quadcopters, the DJI S900 and DJI Phantom 2 Vision+ pictured below (respectively):

DJI S900

Phantom 2

As mentioned here, The DJI Phantom 2 is the same one that the UN Office for the Coordination of Humanitarian Affairs (OCHA) is experimenting with:

Screen Shot 2014-06-24 at 2.22.05 PM

Given the dense rubble and vegetation in the disaster affected region of Ludian County in China, ground surveys were particularly challenging to carry out. So UAVs provided disaster responders with an unimpeded bird’s eye view of the damage, helping them prioritize their search and rescue efforts. DJI reports that the UAVs “were able to relay images back to rescue workers, who used them to determine which roads needed to be cleared first and which areas of the rubble to search for possible survivors. […].”

The video above shows some striking aerial footage of the disaster damage. This is the not first time that UAVs have been used for search and rescue or road clearance operations. Transporting urgent supplies to disaster areas requires that roads be cleared as quickly as possible, which is why UAVs were used for this and other purposes after Typhoon Haiyan in the Philippines. In Ludian, “Aerial images captured by the team were [also] used by workers in the epicenter area […] where most of the traditional buildings in the area collapsed.”

DJI was not the only group to fly UAVs in response to the quake in Yunnan. The Chinese government itself deployed UAVs (days before DJI). As the Associated Press reported several weeks ago already, “A novel part of the Yunnan response was the use of drones to map and monitor a quake-formed lake that threatened to flood areas downstream. China has rapidly developed drone use in recent years, and they helped save time and money while providing highly reliable data, said Xu Xiaokun, an engineer with the army reserves.”

Working with UAV manufacturers directly may prove to be the preferred route for humanitarian organizations requiring access to aerial imagery following major disasters. At the same time, having the capacity and skills in-house to rapidly deploy these UAVs affords several advantages over the partnership model. So combining in-house capacity with a partnership model may ultimately be the way to go but this will depend heavily on the individual mandates and needs of humanitarian organizations.


See Also:

  • Humanitarians in the Sky: Using UAVs for Disaster Response [link]
  • Live Crisis Map of UAV Videos for Disaster Response [link]
  • Humanitarian UAV Missions During Balkan Floods [link]
  • UAVs, Community Mapping & Disaster Risk Reduction in Haiti [link]
  • “TripAdvisor” for International UAV/Drone Travel [link]

Welcome to the Humanitarian UAV Network

UAViators Logo

The Humanitarian UAV Network (UAViators) is now live. Click here to access and join the network. Advisors include representatives from 3D Robotics, AirDroids, senseFly & DroneAdventures, OpenRelief, ShadowView Foundation, ICT4Peace Foundation, the United Nations and more. The website provides a unique set of resources, including the most comprehensive case study of humanitarian UAV deployments, a directory of organizations engaged in the humanitarian UAV space and a detailed list of references to keep track of ongoing research in this rapidly evolving area. All of these documents along with the network’s Code of Conduct—the only one of it’s kind—are easily accessible here.

UAViators 4 Teams

The UAViators website also includes 8 action-oriented Teams, four of which are displayed above. The Flight Team, for example, includes both new and highly experienced UAV pilots while the Imagery Team comprises members interested in imagery analysis. Other teams include the Camera, Legal and Policy Teams. In addition to this Team page, the site also has a dedicated Operations page to facilitate & coordinate safe and responsible UAV deployments in support of humanitarian efforts. In between deployments, the website’s Global Forum is a place where members share information about relevant news, events and more. One such event, for example, is the upcoming Drone/UAV Search & Rescue Challenge that UAViators is sponsoring.

When first announcing this initiative,  I duly noted that launching such a network will at first raise more questions than answers, but I welcome the challenge and believe that members of UAViators are well placed to facilitate the safe and responsible use of UAVs in a variety of humanitarian contexts.

Acknowledgements: Many thanks to colleagues and members of the Advisory Board who provided invaluable feedback and guidance in the lead-up to this launch. The Humanitarian UAV Network is result of collective vision and effort.


See also:

  • How UAVs are Making a Difference in Disaster Response [link]
  • Humanitarians Using UAVs for Post Disaster Recovery [link]
  • Grassroots UAVs for Disaster Response [link]
  • Using UAVs for Search & Rescue [link]
  • Crowdsourcing Analysis of UAV Imagery for Search and Rescue [link]

Grassroots UAVs for Disaster Response

I was recently introduced to a new initiative that seeks to empower grassroots communities to deploy their own low-cost xUAVs. The purpose of this initiative? To support locally-led disaster response efforts and in so doing transfer math, science and engineering skills to local communities. The “x” in xUAV refers to expendable. The initiative is a partnership between California State University (Long Beach), University of Hawaii, Embry Riddle, The Philippine Council for Industry, Energy & Emerging Technology Research & Development, Skyeye, Aklan State University and Ateneo de Manila University in the Philippines. The team is heading back to the Philippines next week for their second field mission. This blog post provides a short overview of the project’s approach and the results from their first mission, which took place during December 2013-February 2014.


The xUAV team is specifically interested in a new category of UAVs, those that are locally available, locally deployable, low-cost, expendable and extremely easy to use. Their first field mission to the Philippines focused on exploring the possibilities. The pictures above/below (click to enlarge) were kindly shared by the Filipinos engaged in the project—I am very grateful to them for allowing me to share these publicly. Please do not reproduce these pictures without their written permission, thank you.


I spoke at length with one of the xUAV team leads, Ted Ralston, who is heading back to the Philippines the second field mission. The purpose of this follow up visit is to shift the xUAV concept from experimental to deployable. One area that his students will be focusing on with the University of Manila is the development of a very user-friendly interface (using a low-cost tablet) to pilot the xUAVs so that local communities can simply tag way-points on a map that the xUAV will then automatically fly to. Indeed, this is where civilian UAVs are headed, full automation. A good example of this trend towards full automation is the new DroidPlanner 2.0 App just released by 3DRobotics. This free app provides powerful features to very easily plan autonomous flights. You can even create new flight plans on the fly and edit them onsite.


So the xUAV team will focus on developing software for automated take-off and landing as well as automated adjustments for wind conditions when the xUAV is airborne, etc. The software will also automatically adjust the xUAV’s flight parameters for any added payloads. Any captured imagery would then be made easily viewable via touch-screen directly from the low-cost tablet.


One of the team’s top priorities throughout this project is to transfer their skills to young Filipinos, given them hands on training in science, math and engineering. An equally important, related priority, is their focus on developing local partnerships with multiple partners. We’re familiar with ideas behind Public Participatory GIS (PPGIS) vis-a-vis the participatory use of geospatial information systems and technologies. The xUAV team seeks to extend this grassroots approach to Public Participatory UAVs.


I’m supporting this xUAV initiative in a number of ways and will be uploading the team’s UAV imagery (videos & still photos) from their upcoming field mission to MicroMappers for some internal testing. I’m particularly interested in user-generated (aerial) content that is raw and not pre-processed or stitched together, however. Why? Because I expect this type of imagery to grow in volume given the very rapid growth of the personal micro-UAV market. For more professionally produced and stitched-together aerial content, an ideal platform is Humanitarian OpenStreetMap’s Tasking Server, which is tried and tested for satellite imagery and which was recently used to trace processed UAV imagery of Tacloban.

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I look forward to following the xUAV team’s efforts and hope to report on the outcome of their second field mission. The xUAV initiative fits very nicely with the goals of the Humanitarian UAV Network (UAViators). We’ll be learning a lot in the coming weeks and months from our colleagues in the Philippines.


Crisis Mapping without GPS Coordinates (Updated)

Update: Video introduction to What3Words:

I recently spoke with a UK start-up that is doing away with GPS coordinates even though their company focuses on geographic information and maps. The start-up, What3Words, has divided the globe into 57 trillion squares and given each of these 3-by-3 meter areas a unique three-word code. Goodbye long postal addresses and cryptic GPS coordinates. Hello planet.inches.most. The start-up also offers a service called OneWord, which allows you to customize a one-word name for any square. In addition, the company has expanded to other languages such as Spanish, Swedish and Russian. They’re now working on including Arabic, Chinese, Japanese and others by mid-January 2014. Meanwhile, their API lets anyone build new applications that tap their global map of 57 trillion squares.

Credit: What3Words

When I spoke with CEO Chris Sheldrick, he noted that their very first users were emergency response organizations. One group in Australia, for example, is using What3Words as part of their SMS emergency service. “This will let people identify their homes with just three words, ensuring that emergency vehicles can find them as quickly as possible.” Such an approach provides greater accuracy, which is vital in rural areas. “Our ambulances have a terrible time with street addresses, particularly in The Bush.” Moreover, many places in the world have no addresses at all. So What3Words may also be useful for certain ICT4D projects in addition to crisis mapping. The real key to this service is simplicity, i.e., communicating three words over the phone, via SMS/Twitter or email is far easier (and less error prone) than dictating a postal address or a complicated set of GPS coordinates.

Credit: What3Words

How else do you think this service could be used vis-à-vis disaster response?


Video: Humanitarian Response in 2025

I gave a talk on “The future of Humanitarian Response” at UN OCHA’s Global Humanitarian Policy Forum (#aid2025) in New York yesterday. More here for context. A similar version of the talk is available in the video presentation below.

Some of the discussions that ensued during the Forum were frustrating albeit an important reality check. Some policy makers still think that disaster response is about them and their international humanitarian organizations. They are still under the impression that aid does not arrive until they arrive. And yet, empirical research in the disaster literature points to the fact that the vast majority of survivals during disasters is the result of local agency, not external intervention.

In my talk (and video above), I note that local communities will increasingly become tech-enabled first responders, thus taking pressure off the international humanitarian system. These tech savvy local communities already exit. And they already respond to both “natural” (and manmade) disasters as noted in my talk vis-a-vis the information products produced by tech-savvy local Filipino groups. So my point about the rise of tech-enabled self-help was a more diplomatic way of conveying to traditional humanitarian groups that humanitarian response in 2025 will continue to happen with or without them; and perhaps increasingly without them.

This explains why I see OCHA’s Information Management (IM) Team increasingly taking on the role of “Information DJ”, mixing both formal and informal data sources for the purposes of both formal and informal humanitarian response. But OCHA will certainly not be the only DJ in town nor will they be invited to play at all “info events”. So the earlier they learn how to create relevant info mixes, the more likely they’ll still be DJ’ing in 2025.