The Sensor Web Project uses a network of sensors linked by software and the internet to an autonomous satellite observation response capability. This system of systems is designed with a flexible, modular, architecture to facilitate expansion in sensors, customization of trigger conditions, and customization of responses.
This system has been used to implement a global surveillance program to study volcanos. We have also run sensorweb tests to study flooding, cryosphere events, and atmospheric phenomena.
Coordinating the activities of multiple sensors including space, terrestrial, and airborne to monitor science and hazard events.
In a remote area of the South Atlantic Ocean near Antarctica a volcano begins rumbling. It begins with a few minor tremors, and suddenly fresh lava breaks to the surface out of an existing vent. While there are no inhabitants of the South Sandwich Islands, four times per day the Terra & Aqua satellites fly overhead at 7.5 kilometers per second and an altitude of 705 kilometers. Each of these spacecraft carries a Moderate Resolution Imaging Spectrometer (MODIS) instrument, acquiring (250m-1000m/pixel) resolution data of the South Sandwich Islands as part of a 2700 kilometer wide swath of imagery.
These data are streamed to and processed at the Distributed Active Archive Center (DAAC) at the Goddard Space Flight Center where the University of Hawaii developed MODVOLC algorithms automatically detect the "hot spot" signature of the volcanic activity within hours of data acquisition. Software monitoring the MODVOLC web site matches this new alert with a previously specified science team interest in volcanoes in this region and generates an observation request to the Earth Observing One (EO-1) Ground System. Based on the priority of the request, the ground system uplinks the observation request to the EO-1 Spacecraft. Onboard Artificial Intelligence software evaluates the request, orients the spacecraft, and operates the science instruments to acquire high resolution (pan-band up to 10m/pixel) images with hyperspectral (220+ bands) data for science analysis. Onboard this data is processed to extract the signature of the volcanic eruption, downlinking this vital information within hours.
Project is currently running, with the goal of monitoring the Earth's 50 most active volcanos.
The MODVOLC webpage: realtime volcanism
A wide range of operational satellite/platforms make their data freely available (e.g. broadcast or internet) in a rapid fashion (tens of minutes to several hours from acquisition). For example, data from the Moderate Resolution Imaging Spectrometer (MODIS) flying on Terra and Aqua are available via Direct Broadcast in near real-time for regional coverage and 3-6 hours from acquisition from the GSFC Distributed Active Archive Center (DAAC) (for global coverage). These data provide regional or global coverage with a wide range of sensing capabilities. For example, MODIS covers the globe roughly 4 times daily (two day and two night overflights). QuickSCAT covers the majority of the globe daily.
Unfortunately, these global coverage instruments do not provide the high resolution data desirable for many science applications. The above instruments range in resolution from MODIS with 250m-1km resolution to 1km and above for the other instruments. While ideally, high resolution data would be available continuously with global coverage, typically high resolution assets can image only limited swathes of the Earth -- thus making them highly constrained and high-demand assets.
In our project, we have networked sensors and science event recognizers/trackers with an automated response system to form a sensorweb, defined as follows. Sensorweb : A networked set of instruments in which information from one or more sensors is automatically used to reconfigure the remainder of the sensors
A dust storm over the persian gulf
Specifically, in our application, we use low resolution, high coverage sensors to trigger observations by high resolution instruments. Note that there are many other rationales to network sensors into a sensorweb. For example automated response might enable observation using complementary instruments such as imaging radar, infra-red, visible, etc. Or automated response might be used to apply more assets to increase the frequency of observation to improve the temporal resolution of available data.
Our sensorweb project is being used to monitor the Earth's 50 most
active volcanos. We have also run sensorweb experiments to monitor
flooding, wildfires, and cryospheric events (snowfall and melt, lake
freezing and thawing, sea ice formation and breakup.)
Arizona State University:
University of Arizona: