Daniel Q. Tran

Onboard processing of multispectral and hyperspectral data of volcanic activity for future Earth-orbiting and planetary missions

Autonomous onboard processing of data allows rapid response to detections of dynamic, changing processes. Software that can detect volcanic eruptions from thermal emission has been used to retask the Earth Observing 1 spacecraft to obtain additional data of the eruption. Rapid transmission of these data to the ground, and the automatic processing of the data to generated images, estimates of eruption parameters and maps of thermal structure, has allowed these products to be delivered rapidly to volcanologists to aid them in assessing eruption risk and hazard. Such applications will enhance science return from future Earth-orbiting spacecraft and also from spacecraft exploring the Solar System, or beyond, which hope to image dynamic processes. Especially in the latter case, long communication times between the spacecraft and Earth exclude a rapid response to what may be a transient process — only using onboard autonomy can the spacecraft react quickly to such an event.

Global spectroscopic survey of cloud thermodynamic phase at high spatial resolution, 2005–2015

The distribution of ice, liquid, and mixed phase clouds is important for Earth’s planetary radiation budget, impacting cloud optical properties, evolution, and solar reflectivity. Most remote orbital thermodynamic phase measurements observe kilometer scales and are insensitive to mixed phases. This under-constrains important processes with outsize radiative forcing impact, such as spatial partitioning in mixed phase clouds. To date, the fine spatial structure of cloud phase has not been measured at global scales. Imaging spectroscopy of reflected solar energy from 1.4 to 1.8 μm can address this gap: it directly measures ice and water absorption, a robust indicator of cloud top thermodynamic phase, with spatial resolution of tens to hundreds of meters. We report the first such global high spatial resolution survey based on data from 2005 to 2015 acquired by the Hyperion imaging spectrometer onboard NASA’s Earth Observer 1 (EO-1) spacecraft. Seasonal and latitudinal distributions corroborate observations by the Atmospheric Infrared Sounder (AIRS). For extratropical cloud systems, just 25 % of variance observed at GCM grid scales of 100 km was related to irreducible measurement error, while 75 % was explained by spatial correlations possible at finer resolutions. Copyright statement. The author’s copyright for this publication is transferred to California Institute of Technology. Government sponsorship acknowledged.

Sensor Web operations: Rapid data acquisition and product generation during a volcanic crisis

The autonomous Model-based Volcano Sensor Web (MSW), based at JPL, proved its worth during a volcanic crisis at Nyamulagira, Democratic Republic of Congo, in 2006. The MSW facilitated the rapid acquisition of spacecraft data which allowed pinpointing the location of the volcanic vent. This was vital in predicting lava flow direction and extent. In 2007 a number of improvements have been made to the MSW. These include the deployment of in situ SO2 sensors on Kilauea volcano, HI, capable not only of triggering requests by the EO-1 spacecraft in the event of anomalous SO2 detection, but also of being triggered autonomously by an anomalous thermal detection from advanced data processing software onboard EO-1, and the conversion of the sensor web to using Open Geospatial Consortium Web Services. The Sensor Web is monitoring volcanoes around the world. A number of volcanic eruptions have been detected and monitored, including a carbonatite eruption at Oldoinyo Lengai, Tanzania, and the March 2008 summit eruption of Kilauea, Hawai¿i, that occurred in the Halema¿uma¿u caldera. Data and products were also obtained during the 2008 eruption of Etna, Sicily. These products were distributed to volcanologists in the UK and Italy.