Eric Pilger

Automated volcanic eruption detection using MODIS

Abstract The moderate resolution imaging spectroradiometer (MODIS) flown on-board NASAs first earth observing system (EOS) platform, Terra, offers complete global data coverage every 1–2 days at spatial resolutions of 250, 500, and 1000 m. Its ability to detect emitted radiation in the short (4 μm)- and long (12 μm)-wave infrared regions of the electromagnetic spectrum, combined with the excellent geolocation of the image pixels (∼200 m), makes it an ideal source of data for automatically detecting and monitoring high-temperature volcanic thermal anomalies. This paper describes the underlying principles of, and results obtained from, just such a system. Our algorithm interrogates the MODIS Level 1B data stream for evidence of high-temperature volcanic features. Once a hotspot has been identified, its details (location, emitted spectral radiance, satellite observational parameters) are written to an ASCII text file and transferred via file transfer protocol (FTP) to the Hawaii Institute of Geophysics and Planetology (HIGP), where the results are posted on the Internet ( http://modis.higp.hawaii.edu ). The global distribution of volcanic hotspots can be examined visually at a variety of scales using this website, which also allows easy access to the quantitative data contained in the ASCII files themselves. We outline how the algorithm has proven robust as a hotspot detection tool for a wide range of eruptive styles at both permanently and sporadically active volcanoes including Soufriere Hills (Montserrat), Popocatepetl (Mexico), Bezymianny (Russia), and Merapi (Java), amongst others. We also present case studies of how the system has allowed the onset, development, and cessation of discrete eruptive events to be monitored at Nyamuragira (Congo), Piton de la Fournaise (Reunion Island), and Shiveluch (Russia).

Ground-based Infrared Monitoring Provides New Tool for Remote Tracking of Volcanic Activity

Thermal monitoring of active volcanoes has long been the domain of satellite and airborne remote sensing (for reviews of current capabilities, see Harris et al. [2002]). However, ground-based thermal sensors offer considerable benefits in that (1) they can be located beneath cloud decks that prohibit aerial views; (2) they allow small thermal targets to be resolved; (3) they observe targets with a constant viewing geometry for long periods of time; and (4) they provide data at high sample rates (tens to hundreds of Hz). This latter capability is extremely attractive when tracking transient or rapidly evolving events, such as volcanic explosions. In addition, when used in conjunction with other geophysical data sets, thermal time series reveal clues as to the manner in which a volcanic system is erupting.

Development of the Mission Operations Support Tool (MOST)

The Hawaii Space Flight Laboratory (HSFL) was established at the University of Hawaii at Manoa in 2007 and is developing a launch vehicle and satellites. The second HSFL launch, scheduled for 2012, is STU-2, which includes a spacecraft being designed and built by the HSFL. Control of the HSFL missions will be done in the HSFL Mission Operations Center located on the University of Hawaii campus at Manoa. HSFL, in collaboration with NASA Ames Research Center and Santa Clara University, is developing a comprehensive openarchitecture space mission operations system (COSMOS) to support this and future space missions. The major software tool of COSMOS, which is intended to provide real-time monitoring and control of spacecraft, is the Mission Operations Support Tool (MOST). This tool is based on the software tool LUNOPS which was designed for and used in support of science mission operations of the Clementine lunar mission in 1994. LUNOPS enabled the flight controllers to monitor the status of the spacecraft in accomplishing its science mission. MOST is building on this concept to allow not only monitoring of the spacecraft status, but also to provide a capability for issuing commands to the spacecraft and to be used in simulations, training and rehearsals, engineering data trending and archiving, and for anomaly resolution. The design goal for MOST is to create a single tool that can tie multiple data streams together with multiple end users. Toward this end, MOST is being designed to accept data inputs from multiple sources; while at the same time supporting multiple display configurations. On the data end, it can retrieve time stamped data records either from disk, or over established network protocols. These data can be archival, or real time; in the past, or in the future; real or simulated. MOST is capable of following data in real time, or tracking backwards and forwards in time. MOST supports one main overview screen, with summary data that is relevant to all users, plus multiple secondary screens designed for various support and subsystem tasks. The main display is always present, while the secondary screens can be displayed and dismissed at will. From the perspective of Mission Operations, this design allows each support specialty to hand tailor the display to their needs, while still maintaining access to all other information. From the perspective of monitoring and troubleshooting, the access to archival data allows studies of the interactions of different subsystems over time. MOST also provides a background monitoring mode that allows “lights-out” operation that will inform members of the operations team when an anomaly has been detected. Finally, the ability to work with simulated data allows the creation of virtual missions, for training, and support for forward looking for Mission Planning and testing.

Hawai'iSat-1: Development Of A University Microsatellite For Testing a Thermal Hyperspectral Imager

The Hawaiʻi Space Flight Laboratory (HSFL) was established at the University of Hawaiʻi (UH) at Manoa for two primary purposes: (1) to educate students and help prepare them to enter the technical workforce, and (2) to help establish a viable space industry that will benefit the State of Hawaiʻi. The second HSFL space mission, currently scheduled to be launched in late 2012, is STU-2, which includes a spacecraft being designed and built by the HSFL called HawaiʻiSat-1. The Operationally Responsive Space (ORS) Office located at Kirtland Air Force Base in New Mexico oversees the LEONIDAS contract, under which the STU-2 mission and the HawaiʻiSat-1 satellite are being developed. The primary objectives for HawaiʻiSat-1 mission are: (1) to demonstrate the ability of the HSFL to design, build, and operate a small satellite in the 80-kg class as a platform to test new technologies; (2) support the C-band Radar Transponder Experiment (CRATEX) Payload; (3) support the testing of the Thermal Hyperspectral Imager being developed at UH; and (4) perform Earth imaging using the HSFL Imaging Payload. The CRATEX payload, provided by Vandenberg Air Force Base, uses C-band transponders and precise orbit determination (provided by onboard GPS receivers) to help the Department of Defense and NASA calibrate their C-band tracking radars around the world. The HawaiʻiSat-1 spacecraft will be placed into a 550-km circular 9 p.m. ascending Sun Synchronous Orbit to optimize its support of the CRATEX payload. The 85-kg HawaiʻiSat-1 spacecraft is 3-axis stabilized using three magnetic torque rods and a reaction wheel for attitude control; and three sun sensors plus two inertial measurement units (each including a 3-axis magnetometer) for attitude determination. Communication is provided by S-band and UHF-band transceivers linked to a ground station located in the Kauaʻi Community College in Hawaiʻi, and other partner ground stations. Control of the mission will be done in the HSFL Mission Operations Center located on the University of Hawaiʻi campus at Manoa. Integration and testing of the spacecraft will be done in the clean rooms at the HSFL facilities on the UH campus, which includes a 1.6 meter diameter thermal vacuum chamber. The HSFL is using a core team of experienced professionals supplemented with graduate and undergraduate students to design, build, and test the HawaiʻiSat-1 spacecraft within a period of approximately two years from System Requirements Review until ready for launch. To keep the spacecraft cost to a minimum, commercial-off-the-shelf (COTS) components will be used when possible. The fairly benign radiation environment of such a low altitude orbit and the use of aluminum sheeting to shield the critical avionics, make the risk of using COTS for a 2-3 year mission to be acceptable while greatly reducing the cost as compared to using space-hardened parts.

Mission design and operations of a constellation of small satellites for remote sensing

The Hawaii Space Flight Laboratory (HSFL) at the University of Hawaii at Manoa is developing the capabilities to design, build, and operate constellations of small satellites than can be tailored to efficiently execute a variety of remote sensing missions. With the Operationally Responsive Space (ORS) Office, HSFL is developing the Super Strypi launch vehicle that on its initial mission in 2013 will launch the HSFL 55-kg HawaiiSat-1 into a near polar orbit, providing the first deployment of these technologies. This satellite will be carrying a miniature hyperspectral thermal imager developed by the Hawaii Institute of Geophysics and Planetology (HIGP). HSFL has also developed a method to efficiently deploy a constellation of small satellites using a minimal number of launch vehicles. Under a three-year NASA grant, HSFL is developing a Comprehensive Open-architecture Space Mission Operations System (COSMOS) to support these types of missions. COSMOS is being designed as a System of Systems (SoS) software integrator, tying together existing elements from different technological domains. This system should be easily adaptable to new architectures and easily scalable. It will be provided as Open Source to qualified users, so will be adoptable by even universities with very restricted budgets. In this paper we present the use of COSMOS as a System of Systems integrator for satellite constellations of up to 100 satellites and numerous ground stations and/or contact nodes, including a fully automated “lights out” satellite contact capability.

On the development of a 6DoF GNC framework for docking multiple small satellites

Small and very capable satellites are becoming an attractive option for future space missions by reducing the cost, decreasing the risk and improving exibility. Small satellites can also be used as building blocks of large space structures such as solar panels or space telescopes. This work is focused on the development of a position and attitude GNC framework for docking multiple small satellites in a cooperative manner using the Comprehensive Open-architecture Solution for Mission Operations Systems (COSMOS) developed at the Hawaii Space Flight Laboratory. We introduce a 6DoF guidance law for position and attitude that optimizes fuel consumption and use the COSMOS software agents to bundle individual satellite dynamics for a realistic simulation. By using the COSMOS agents each satellite can broadcast its information to the network making it available to all other satellites. An important outcome of this work is the development of the ight-like software that can be used in real time simulation environments and for mission rehearsals.

TIRCIS: thermal infrared compact imaging spectrometer for small satellite applications

TIRCIS (Thermal Infra-Red Compact Imaging Spectrometer), uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. The instrument has a mass of <10 kg and dimensions of 53 cm × 25 cm × 22 cm. The optical design yields a 120 m ground sample size given an orbit of 500 km. Over the wavelength interval of 7.5 to 14 microns up to 90 spectral samples are possible. Our performance model indicates signal-to-noise ratios of 400-800:1.

COSMOS — An innovative nodal architecture for controlling large numbers of small satellites and other diverse assets

The Hawaii Space Flight Laboratory (HSFL) at the University of Hawaii at Manoa developed the Comprehensive Open-architecture Solution for Mission Operations Systems (COSMOS) under a three-year NASA grant. This innovative suite of software and hardware was initially designed for supporting the operations of multiple small satellites, but during its development, it evolved into a comprehensive system of systems that is capable of providing nearly all operations functions to support an integrated system of objects to be monitored and controlled, called nodes. These nodes are not limited to spacecraft, but can be almost any type of vehicle or electronic entity that has communication connectivity with the distributed COSMOS system. Even the vehicles themselves can operate COSMOS as their onboard controlling software. HSFL built a 55-kg satellite called Hiakasat that is due to launch on the ORS-4 mission in 2015. This satellite uses COSMOS for its onboard flight software, which integrates seamlessly with the COSMOS system that is being used to operate the mission on the ground. COSMOS is currently being used to monitor research ship gathering data, and even controlling rovers on simulated lunar missions. This innovative nodal architecture will allow a fully integrated system that can combine satellites with UAVs, submersible, ships, and other robotic craft.

Expanding the Comprehensive Open-architecture Space Mission Operations System (COSMOS) for integrated Guidance, Navigation and Control of Multiple Small Satellites

The idea of using multiple small satellites is becoming very attractive for future space missions. As a consequence the cooperative motion for teams of autonomous small spacecraft systems is also becoming increasingly important for maneuvers such formation ying, docking and proximity operations for small satellites. This paper describes the work we have developed to address some of these problems by creating an integrated framework for Guidance, Navigation and Control (iGNC) for two satellites using the Comprehensive Open-architecture Space Mission Operations System (COSMOS). We also present a new guidance law that optimizes fuel consumption for the two-satellite system. An important outcome of this work is the development of a comprehensive software that extends the iGNC framework to almost ight-ready software that is modular and easy to improve, and can also be used for mission simulation rehearsals.

Design and operation of SUCHI: the space ultra-compact hyperspectral imager for a small satellite

The primary payload on the University of Hawaii-built ‘HiakaSat’ micro-satellite will be the Space Ultra Compact Hyperspectral Imager (SUCHI). SUCHI is a low-mass (<9kg), low-volume (10x10x36 cm3) long wave infrared hyperspectral imager designed and built at the University of Hawaii. SUCHI is based on a variable-gap Fabry-Perot interferometer employed as a Fourier transform spectrometer with images collected by a commercial 320x256 microbolometer array. The microbolometer camera and vacuum-sensitive electronics are contained within a sealed vessel at 1 atm. SUCHI will collect spectral radiance data from 8 to 14 microns and demonstrate the potential of this instrument for geological studies from orbit (e.g. mapping of major rock-forming minerals) and volcanic hazard observation and assessment (e.g. quantification of volcanic sulfur dioxide pollution and lava flow cooling rates). The sensor has been integrated with the satellite which will launch on the Office of Responsive Space ORS-4 mission scheduled for 2014. The primary mission will last 6 months, with extended operations anticipated for approximately 2 years. A follow-on mission has been proposed to perform imaging of Earth’s surface in the 3-5 micron range with a field of view of 5 km with 5.25 m sampling (from a 350 km orbit). The 19-kg proposed instrument will be a prototype sensor for a constellation of small satellites for Earth imaging. The integrated satellite properties will be incorporated into the Hawaii Space Flight Laboratory’s constellation maintenance software environment COSMOS (Comprehensive Openarchitecture Space Mission Operations System) to ease future implementation of the instrument as part of a constellation.