FLOATS

The Fiberoptic Laser Operated Temperature Sensor (FLOATS) is an instrument that makes high spatial and temporal resolution measurements of temperature profiles throughout the Tropical Tropopause Layer. The instrument operates by deploying a long fiber optic cable from the balloon gondola once it has reached a stable float altitude. A laser in the balloon gondola inject thousands of pulses of light into the suspended fiber every second. A small fraction of the light from each pulse is scattered from the glass core of the fiber optic cable, and returns back up the fiber to the gondola. By measuring the intensity of this scattered light at two different wavelengths, and the time it takes for the light to return to the gondola, the temperature along the fiber can be determined every meter.