ISO 28902-3:2018 空気の質—環境気象学—パート3：連続波ドップラーライダーによる地上の風のリモートセンシング | ページ 6

3.1

data availability

ratio between the number of actual considered measurement data with a predefined data quality and the number of expected measurement data for a given measurement period

Note 1 to entry: In the wind industry, this term commonly applies to measurements averaged over a standard period of 10 min.

3.2

displayed range resolution

spatial interval between the centres of two successive range measurements

3.3

effective range resolution

application-related variable describing an integrated range interval for which the target variable is delivered with a defined uncertainty

[SOURCE: ISO 28902-1:2012, 3.14, modified — The example has been deleted.]

3.4

effective temporal resolution

application-related variable describing an integrated time interval for which the target variable is delivered with a defined uncertainty

[SOURCE: ISO 28902-1:2012, 3.12, modified — The symbol and the example has been deleted.]

3.5

extinction coefficient

α

measure of the atmospheric opacity, expressed by the natural logarithm of the ratio of incident light intensity to transmitted light intensity, per unit light path length

[SOURCE: ISO 28902-1:2012, 3.10]

3.6

integration time

time spent in order to derive an independent value of the line-of-sight velocity

3.7

maximum acquisition range

R_MaxA

maximum distance at which a lidar signal can be recorded and processed

Note 1 to entry: It depends primarily on the laser wavelength and transmitter aperture size; also, to some extent, it depends on the number of acquisition points and the sampling frequency.

3.8

minimum acquisition range

R_MinA

minimum distance from which a lidar signal can be recorded and processed

Note 1 to entry: If the minimum acquisition range is not given, it is assumed to be zero. It can be different from zero, when the reception is blind by focusing limitations.

3.9

maximum operational range

R_MaxO

maximum distance to which a wind speed can be derived with confidence from the lidar signal

Note 1 to entry: The maximum operational range is less than or equal to the maximum acquisition range.

Note 2 to entry: The maximum operational range is defined along an axis corresponding to the application. It is measured vertically for vertical wind profiler. It is measured horizontally for scanning lidars able to measure in the full hemisphere.

Note 3 to entry: The maximum operational range depends on lidar parameters but also on atmospheric conditions, particularly the extinction coefficient.

3.10

measurement period

interval of time between the first and last measurements

[SOURCE: ISO 28902-2:2017, 3.10]

3.11

minimum operational range

R_MinO

minimum distance where wind speed can be derived with confidence from the lidar signal

Note 1 to entry: The minimum operational range is also called blind range.

Note 2 to entry: In continuous-wave lidars, the minimum operational range is determined by the closest position of the focus achievable by the transceiver optical system.

3.12

physical range resolution

width [full width at half maximum (FWHM)] of the range weighting function

[SOURCE: ISO 28902-2:2017, 3.12]

3.13

probe length

width [full width at half maximum (FWHM)] of the spatial weighting function selecting the region in space that contributes to the wind speed computation

Note 1 to entry: The probe length is centred on the measurement distance.

3.14

range resolution

equipment-related variable describing the shortest range interval from which independent signal information can be obtained

[SOURCE: ISO 28902-1:2012, 3.13]

3.15

range weighting function

weighting function of the radial wind speed along the line of sight

[SOURCE: ISO 28902-2:2017, 3.15]

3.16

temporal resolution

equipment-related variable describing the shortest time interval from which independent signal information can be obtained

[SOURCE: ISO 28902-1:2012, 3.11]

3.17

velocity bias

maximum instrumental offset on the velocity measurement

Note 1 to entry: The velocity bias has to be minimized with adequate calibration, for example, on a fixed target.

[SOURCE: ISO 28902-2:2017, 3.17]

3.18

velocity range

range determined by the minimum measurable wind speed, the maximum measurable wind speed and the ability to measure the velocity sign, without ambiguity

Note 1 to entry: Depending on the lidar application, the velocity range can be defined as the radial wind velocity (scanning lidar) or as horizontal wind velocity (wind profiler).

[SOURCE: ISO 28902-2:2017, 3.18]

3.19

velocity resolution

instrumental velocity standard deviation

Note 1 to entry: The velocity resolution is determined by the signal processing bin width.

3.20

wind shear

variation of wind speed across a plane perpendicular to the wind direction

[SOURCE: ISO 28902-2:2017, 3.20]