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Minimum Distance between Climate Station and Obstacle

Source: R/position.R
pos_min_dist.Rd

Calculates the minimum distance required between a climate station and an obstacle (e.g., forest) to ensure independence of measurements.

Usage

pos_min_dist(...)

# Default S3 method
pos_min_dist(obs_width, obs_height, ring = FALSE, obs_radius = NULL, ...)

Arguments

...

Additional arguments.

obs_width

Width of the obstacle in meters (m).

obs_height

Height of the obstacle in meters (m).

ring

Logical. If TRUE, the obstacle surrounds the station circularly.

obs_radius

If ring is TRUE, radius of the circular obstacle in meters (m).

Value

Minimum distance in meters (m).

Minimum distance between the measurement point and the obstacle for undisturbed measurement in meters (m).

Details

The minimum distance is calculated to ensure that the climate station's measurements are not influenced by nearby obstacles. The calculation varies based on whether the obstacle surrounds the station circularly or is positioned behind the station.

Formulas used:

  • For a circularly surrounded obstacle: \(d_{min} = \pi \cdot r + 10 \cdot h\)

  • For an obstacle behind the station:

    • If \(h > w\): \(d_{min} = 0.5 \cdot h + 10 \cdot w\)

    • If \(h < w\): \(d_{min} = 0.5 \cdot w + 10 \cdot h\)

    • If \(h \approx w\) (within \(±5\%\)): \(d_{min} = 5 \cdot (h + w)\)

References

Bendix 2004, p. 189, eq. 9.1.

Examples

# Minimum distance for an obstacle behind the station
pos_min_dist(obs_width = 50, obs_height = 30)
#> [1] 325

# Minimum distance for a circularly surrounded obstacle
pos_min_dist(obs_width = 50, obs_height = 30, ring = TRUE, obs_radius = 100)
#> [1] 614.1593