Fighting Natural Disasters with Satellite Imagery
When a natural disaster threatens lives and property, emergency responders, government officials and concerned citizens quickly need access to accurate up-to-date information to mitigate the damage. Satellite imagery is very effective for monitoring major natural disasters, both before and after an event. Remote sensing satellites offer the benefit of collecting imagery from space over large geographic areas, without endangering people on the ground. Sensors provide a wide variety of data to improve situational awareness for all kinds of events — earthquakes, wildfires, hurricanes, floods, droughts — and the information is used to help predict timing, assess damage, rescue victims, and expedite clean-up and rebuilding. Comprehensive current coverage is a game changer for providing guidance to emergency responders.
Complementary Sources of Imagery
Different sources of remotely sensed imagery provide users options to choose what is best for each situation. There are many factors to consider, including resolution, spectral bands and temporal frequency. Some satellites can be tasked to acquire sub-meter imagery of a specific area every one to two days, while others offer continuous coverage of the same area at lower resolution. Synthetic aperture radar (SAR) collects data day and night through any weather condition, while the shortwave infrared (SWIR) band of an optical sensor “sees” hot spots of a wildfire through smoke. A combination of imagery, such as SAR, SWIR, and natural color (called RGB after the red-green-blue visible bands), collected before, during, and after an event and viewed with layers of GIS data (roads, utilities, schools, hospitals, etc.) provides the most complete picture.
In the U.S., sources of imagery range from government agencies, such as the National Oceanic and Atmospheric Administration (NOAA), to commercial providers like DigitalGlobe and Planet. There is also international cooperation for humanitarian and disaster response projects, so imagery from the European Space Agency, SPOT Image and others are often accessible.
To gain a complete understanding of a situation, responders may start with data from one of the geostationary satellites operated by NOAA that provide data over a huge geographic area. For example, GOES 16 collects wind, water vapor, 13 channels of infrared, and three visible channels over the eastern U.S., Atlantic Ocean and South America, while GOES 15 covers the western U.S. and Pacific Ocean. This continuous coverage is particularly useful for tracking weather patterns and providing early warnings for weather-related disasters.
For more detailed observations, the satellite constellations operated by commercial companies provide a selection of multispectral bands, SWIR and near-infrared (NIR) at resolutions as high as 30 centimeters. These companies routinely make imagery publicly available to support natural disaster response and deliver imagery directly to individual customers through paid subscription plans.
Web-based Apps Provide Access to Imagery
DigitalGlobe, a Maxar company, formally launched its Open Data Program in January 2017 with the intention of publicly releasing pre- and post-event imagery to accelerate response to sudden onset natural disasters. During the first year, imagery from 11 major events were released, including earthquakes, landslides and hurricanes. Currently, there are seven ongoing activations, including flooding in India and humanitarian efforts related to the latest Ebola outbreak in Africa.
“DigitalGlobe supports and fosters the response community worldwide and helps them utilize high-resolution imagery for its best use,” says Rhiannan Price, DigitalGlobe director, Global Development Program. “By partnering with organizations on the ground, we can share this powerful technology and impact the world in a unique and positive way.”
DigitalGlobe releases imagery under a Creative Commons 4.0 license for non-commercial use. Access to imagery showing before and after conditions helps with damage assessment and response. Going forward, additional effort is being put into extracting information to provide actionable intelligence. Also, by integrating data from its high-resolution optical satellites such as WorldView-3 with data from other Maxar business units such as MDA’s RADARSAT-2, DigitalGlobe can provide even better support for global efforts.
“For the Open Data Program activations, users are able to download imagery and any associated vector data we may have released through the website,” Price explains. “We notify the community when there’s an activation, so they can immediately put the data to use in the field. Our partners use the data in a variety of ways — the Humanitarian OpenStreetMap Team (HOT) uses the imagery to crowdsource mapping of critical features; Team Rubicon uses the imagery in their field operations to guide search and rescue missions, clear debris, identify homes for assistance and much more; and the United Nations creates situational reports to evidence the impacts of the disasters and properly allocate resources.”
DigitalGlobe also offers FirstLook, a customized event monitoring service typically purchased by global disaster response organizations, technology companies, governments and non-profits. Through FirstLook, DigitalGlobe collects images of political, disaster and human-interest events, and customers provide feedback on those events to help prioritize future tasking. Examples of FirstLook events include political protests, tornado damage and the Indy 500. Then, pre- and post-imagery is provided to subscribing customers.
High-Temporal Frequency for Continuous Coverage
Planet has a different approach to natural disaster support with its constellation of approximately 150 small satellites collecting imagery of the entire Earth every day. The 130 Dove satellites deliver 3-5 meter resolution imagery, the 13 SkySats collect at .8-meter resolution and five RapidEye satellites collect 5-meter resolution imagery.
Through Planet’s Disaster Data Program, emergency responders can access before and after imagery for non-commercial purposes. Planet is the first private-sector satellite data provider to join The International Charter Space and Major Disasters, a consortium of international space agencies that provides rapid access to satellite data in the event of a natural or man-made disaster. Although active in the organization since 2016, Planet recently formalized its affiliation and agreed to provide a targeted amount of activations per year.
“Planet has a fairly unique niche in disaster response with continuous data feeds for our customers,” says Brittany Zajic, Planet, senior coordinator, Disaster Response Operations. “Planet provides imagery along the entire life cycle — risk reduction, response, recovery and resilience (the four R’s) — although reduction and response is our primary focus.”
The Planet Explorer is a platform used to visualize and interact with Planet’s imagery through the Disaster Data Program. Imagery is available on Planet Explorer within 24 hours of collection. The continuous collection of imagery produced by the Doves, packaged as PlanetScope, allows customers to develop detailed situational awareness, as well as monitor assets during and after the event. Planet also delivers imagery directly to customers through a paid subscription service and is working toward providing more information products.
“Overall, natural disaster responders benefit from a combined macro and micro approach, with access to all data via a web-based platform and analytic tools to leverage the value in each data set,” Zajic says. “Our users look at the PlanetScope 3-5 meter imagery to identify problem areas, and then follow up with SkySat sub-meter imagery to see the details. With this process of ‘Tip and Cue,’ customers gain a better understanding of what is going on and can create a warning and response system.”
Specialists in Natural Disaster Analytics
There are multiple sources of satellite imagery; however, in the middle of a crisis, accurately finding, interpreting, processing and disseminating this critical information during fast-paced disaster response operations can be difficult. That’s why companies like Intterra are so important. Intterra, based in Castle Rock, Colo., specializes in providing its fire community customers with a centralized visual interface for their data. They’re the developer of a cloud-based situational awareness software that includes tools for incident management, preplanning and damage assessment, analytics and reporting, and even a Field Tool app (for users working in the field with limited communications). The U.S. Forest Service’s National Interagency Fire Center (NIFC) uses Intterra for their Enterprise Geospatial Portal (EGP), and Intterra is also used by many other metropolitan and wildland fire departments across the U.S.
By aggregating information from all available sources, and applying machine learning and industry expertise, Intterra produces intelligent geovisualizations to support everyone involved with wildfires. As the size and severity of wildland-urban fires increases, analysis aids with decision-making and management of emergent incidents during a disaster.
“Our goal is to get data into the hands of emergency responders quickly and easily,” says Krista West, remote sensing scientist, Intterra. “Our web-based app is fast even though there is a large volume of data, and we are constantly improving its performance. Incident Command Posts (ICP) can view information on big-screen TVs, while firefighters in the field have access to up-to-date information through their phones or tablets. Field users are also able to add information to their Intterra apps to transmit data back to the ICP in real-time. It’s all about sharing information.”
Intterra’s standard imagery offerings in its Satellite Intel Tool include RGB, SWIR for seeing through smoke and haze, and NIR to determine vegetation health. Other kinds of imagery, such as radar or LiDAR, can be acquired upon request.
During the client onboarding process, Intterra ingests all types of GIS layers and data sources that could be useful to a client, including a variety of base maps, specific agency information (like critical infrastructure, school zones, dams, etc.), and Computer Aided Dispatch (CAD), Automatic Vehicle Location (AVL) and Records Management Systems (RMS) data. The U.S. Forest Service, for example, has information about structures, wilderness maps and animal habitats included in its EGP system.
“We automatically ingest data from WorldView-2 and SPOT 6 and 7, and Sentinel-2 and WorldView-3 provide SWIR bands, which are really essential for our work,” West says. “We also find the high temporal frequency of Planet’s RGB and NIR imagery extremely valuable because conditions can change so fast. GOES-16 is on my wish list for stationary coverage, and we intend to add automatic ingests from Landsat 8 as well. The more imagery, the better.”
Remote sensing products and services will continue to focus on accelerating response time and delivering more actionable information into the hands of first responders. This includes a focus on machine learning capabilities to rapidly extract features like buildings, roads and flooded areas from satellite imagery. By leveraging the complementary advantages of different sensors, more informed decisions can be made to improve safety and situational awareness. Advanced imagery and derivative products also support rebuilding and recovery efforts long after a disaster has occurred.