Newly developed instruments by the Precision Instrument Development Center (PIDC) under the National Science Council will increase researchers' abilities to capture images of red sprites, very large flashes of red light excited in the high atmosphere above thunderstorms by positive cloud-to-ground lightning strokes, officials at the center said yesterday.
The newly built device, which is composed of specially designed photometers and imagers, was developed by researchers at the PIDC.
"When photometers sense signals from red sprites, they will function automatically," said Huang Ting-ming (
Both red sprites and blue jets are upper atmospheric optical phenomena associated with thunderstorms that have only recently been documented using low-light-level television technology.
The first images of a red sprite in the world were captured by US researchers accidentally in 1989. Afterward, US' NASA successfully captured about 20 images from space shuttles in 1989 and 1993. Since 1993, over 1,000 images of the sprites have been captured by instruments installed both on the ground and on aircraft.
In Taiwan, a research team at National Cheng Kung University first captured images of red sprites in April last year using ground-based commercial instruments.
Last July, in southern Taiwan, the team successfully captured high-resolution images of a rare "giant blue jet," which feeds energy from thunderstorms up into the Earth's ionosphere, from the ground. According to the NSC, it was the second time in the world that images of the phenomenon have been captured.
Huang said that data recorded by the portable red sprite imaging device would be further analyzed to help researchers to determine spatial, temporal and spectral properties of the natural phenomenon.
To get an image of a red sprite, one must place the device on the ground during clear skies to capture images of lightening occurring in remote storms, Huang said.
Huang said that researchers at the center successfully demonstrated the device's ability to capture images of an artificial red sprite in a lab.
Huang said that the machine actually could also take images of blue jets if some filters are replaced.
PIDC officials said that instruments developed by the center could also be used for industrial use. The imager can be used to monitor the environment or strengthen the coastal security system. The photometer can be used to hunt leaks during the process of producing semiconductors.
Currently, the center is involved in R&D of an experiment pertaining to ROCSAT 2 (華衛二號). PIDC officials said yesterday that one of their long-term goals is to develop a spacecraft-based optical remote sensing telescope.
The imager of sprites and upper atmospheric lightning (ISUAL) experiment on ROCSAT 2, officials said, would make the first spacecraft-based measurements of lightning induced upper atmospheric optical flash transients, such as sprites, blue jets and elves.
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