5:15 PM - 6:30 PM
[MIS03-P13] Development of the quasi-real-time monitoring of volcanic lava activity using MODIS
Keywords:MODIS, Volcano, Remote Sensing
We introduce an evaluation function S to remove the spatial and temporal variation from the spatial difference of the brightness temperature data between the target point and reference point (5 km distance). When we compute the differences, we need to eliminate cloud effects adequately. To achieve this, we use the brightness temperature difference between bands of MODIS (BTD). In this study, we select the following combinations ; (1) Band34-Band35 (BTD(t)-μ < kσ, k=-2.0:), (2) Band31-Band27 ( BTD(t)-μ < kσ, k=-2.6), (3) Band31-Band32 (|BTD(t)-μ| < kσ, k=-3.0), and (4) Band20-Band31 (|BTD(t)-μ| < kσ, k=-3.0). Where t, k, m, and s are the season, threshold for cloud identification, average, standard deviation for each distribution of BTD. Until the distribution satisfy the equation, we repeat the test. Then, we move to the next test. We perform this procedure up to test 4. Then we get the pixels without cloud. The result is evaluated using LIDAR data onboard CALIPSO, which has the almost same orbit and constellated with AQUA. After removing the cloud effect, we compute the deviation rate d. As results for 15 years data analysis for 7 volcanoes in Indonesia, when the deviation rate exceeds in target volcanoes 6σ, there is a tendency to have a lava volcanic activities. However, without removing the cloud effects, we find it is difficult to identify the anomaly related to the lava activities. Therefore, it is highly suggestive of the proposed method is valid for monitoring volcanoes and volcanic risk reduction.