Eruptions of Mayon Volcano in Summer 2006
Ground observations by using web cameras
It is very hard to recognize hot anomalies in the original NIR images downloaded
from the web camera.
An enhanced NIR image is obtained by maximally stretching a range of the brightness of the Green
band of an original image. Then it is expressed as follows:
(a) A rainbow expression of the stretched image at 0509 LST on 4 Aug. 2006.
(b) A superposition of the image (a) on a morning image at 0649 LST on 5 Aug. 2006.
(c) A composite image of Red: the stretched one at 0509 LST on 5 Aug. 2006 with Green & Blue: the same background image data of the image (b), as indicated in the figure.
(d) A rainbow expression of the stretched image at 0519 LST on 5 Aug. 2006.
(e) A composite image of Red: the stretched one at 1948 LST on 19 Aug. 2006 with Green & Blue: at 1345 LST on 20 Aug. 2006
In the file name 0608ddhhmm with 0608= Aug. 2006, dd= date, hh= hour and mm= minute, we use JST = LST+1, where LST is the local standard time in the Philippines. The time stamp at the top left corner according to the clock of the network camera is somewhat shifted from LST.
Left column (ir): NIR images with enhanced Green (eG) and original (without eG) images.
Right column (vis): visible images.
