Calculate inverse relative distance Earth-Sun for daily and shorther periods.
Usage
dr(x)
Arguments
x
date-time object or Day of the year
Details
References
Allen, R. G., Pereira, L. S., Raes, D., & Smith, M. (1998). Crop evapotranspiration-Guidelines for computing crop water requirements-FAO Irrigation and drainage paper 56. FAO, Rome, 300(9).