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[STT37-P02] Development of a multiband uncooled infrared cameras prototype system for imaging volcanic sulfur dioxide (SO2) gas and temperature distribution
Keywords:SO2 gas, volcano observations, infrared remote sensing
Measuring the SO2 gas amount emitted from volcanoes is useful for predicting the short-term activity of a volcano. As a method for this, under the “Promotion Project for Next Generation Volcano Research Theme B subtheme 2 subtopic 2-2: Development of Remote Sensing Techniques for Surface Phenomena of Volcano”, we have been developing an imaging system for remotely sense SO2 gas. Under this project, we are planning to develop a new observation device called a surface phenomena imaging camera with uncooled infrared camera (SPIC-UC). We aim to make the SPIC-UC a handheld imaging system that can be used both on ground and airborne systems.
In this study, we present results of the development a multiband uncooled infrared cameras system: SPIC-UC-4VGA prototype for a prototype of the SPIC-UC. The SPIC-UC-4VGA prototype consists of four uncooled infrared cameras equipped with internal optical filter (Camera 1, Camera 2, Camera 3 and Camera 4). All these cameras employ a focal plane array (FPA)-type amorphous silicon microbolometer element. The Camera 1 measures 7500–14000 nm region, the Camera 2 measures 9000–14000 nm region, the Camera 3 measures 7950–9300 nm region which matched to SO2 absorption bands, the Camera 4 measures 11750–12750 nm region which has no SO2 absorption. These four cameras can acquire frame-synchronized data at 30fps. The SPIC-UC-4VGA prototype has been realized as an environment-resistant type in consideration of outdoor use. The performance evaluations indicate that all Camera achieved absolute temperature accuracy of within ±2K. The Camera 3 for SO2 detection can achieve a NETD of approximately 0.39 K. The evaluation of SO2 measurement accuracy by simulation using the same SO2 gas concentration distribution conditions as our original airborne hyperspectral sensor’s (ARTS) actual observation on Apr. 8 2008 at Sakurajima volcano reveals that the developed Camera 3 can be detected SO2 gas concentration distributions within errors of ±1 ppmv under the background conditions in the 50 °C ground surface. These results indicate that the developed SPIC-UC-4VGA prototype can be used for volcanic SO2 gas quantitative detection.
In this study, we present results of the development a multiband uncooled infrared cameras system: SPIC-UC-4VGA prototype for a prototype of the SPIC-UC. The SPIC-UC-4VGA prototype consists of four uncooled infrared cameras equipped with internal optical filter (Camera 1, Camera 2, Camera 3 and Camera 4). All these cameras employ a focal plane array (FPA)-type amorphous silicon microbolometer element. The Camera 1 measures 7500–14000 nm region, the Camera 2 measures 9000–14000 nm region, the Camera 3 measures 7950–9300 nm region which matched to SO2 absorption bands, the Camera 4 measures 11750–12750 nm region which has no SO2 absorption. These four cameras can acquire frame-synchronized data at 30fps. The SPIC-UC-4VGA prototype has been realized as an environment-resistant type in consideration of outdoor use. The performance evaluations indicate that all Camera achieved absolute temperature accuracy of within ±2K. The Camera 3 for SO2 detection can achieve a NETD of approximately 0.39 K. The evaluation of SO2 measurement accuracy by simulation using the same SO2 gas concentration distribution conditions as our original airborne hyperspectral sensor’s (ARTS) actual observation on Apr. 8 2008 at Sakurajima volcano reveals that the developed Camera 3 can be detected SO2 gas concentration distributions within errors of ±1 ppmv under the background conditions in the 50 °C ground surface. These results indicate that the developed SPIC-UC-4VGA prototype can be used for volcanic SO2 gas quantitative detection.