Environmental measurement system and environmental measurement method

An environmental measurement system comprising:

• a first optical fiber and a second optical fiber which are different at least in any one of heat capacity and heat conductivity;
• a temperature measurement device configured to input light into the first optical fiber and the second optical fiber, and to receive backscattered light outputted from the first optical fiber and the second optical fiber to measure temperature distribution in a longitudinal direction of the first optical fiber and the second optical fiber;
• and
• an analyzer configured to analyze a variation over time of the temperature distribution outputted from the temperature measurement device to calculate a temperature and a wind velocity in a measurement position where the first optical fiber and the second optical fiber are located,
• wherein the analyzer calculates a ratio between a fluctuation range of a temperature at a portion of the first optical fiber located in the measurement position and a fluctuation range of a temperature at a portion of the second o t cal fiber located in the measurement position.

An environmental measurement method comprising:

• locating a first measurement portion and a second measurement portion of an optical fiber in a single measurement position;
• inputting light into the optical fiber and measuring a variation over time of a temperature at the first measurement portion and a variation over time of a temperature at the second measurement portion based on backscattered light outputted from the optical fiber;
• calculating a temperature in the measurement position based on at least any one of the variation over time of the temperature at the first measurement portion and the variation over time of the temperature at the second measurement portion;
• and
• calculating a wind velocity in the measurement position based on a ratio between a fluctuation range of the temperature at the first measurement portion and a fluctuation range of the temperature at the second measurement portion, wherein
• the first measurement portion and the second measurement portion of the optical fiber respectively include covering layers which are different at least in any one of heat capacity and heat conductivity.