초록 ▼

An irrigation controller collects daily high and low temperature data. The controller then processes this collected temperature data in accordance with the Hargreaves equation to determine a reference evapotranspiration value. The controller further adjusts the reference evapotranspiration value to

An irrigation controller collects daily high and low temperature data. The controller then processes this collected temperature data in accordance with the Hargreaves equation to determine a reference evapotranspiration value. The controller further adjusts the reference evapotranspiration value to account for the type of vegetation at the site and a localized Hargreaves equation deviation factor to generate an adjusted evapotranspiration value which represents an estimation of the current watering needs for the specific plants at that specific site. The controller then divides the locally adjusted evapotranspiration value by a sprinkler head average precipitation rate to determine a run time for irrigation. Irrigation for the site is then initiated lasting for the duration of the determined run time.

대표청구항 ▼

[ What is claimed is:] [1.]1. An irrigation controller, comprising:a memory for storing extraterrestrial radiation influenced equivalent evaporation data for a certain site;means for measuring temperature data at that certain site;a processing unit connected to the memory and receptive of the temper

[ What is claimed is:] [1.]1. An irrigation controller, comprising:a memory for storing extraterrestrial radiation influenced equivalent evaporation data for a certain site;means for measuring temperature data at that certain site;a processing unit connected to the memory and receptive of the temperature data, the processing unit operable to execute an irrigation application program which:calculates solely from the received temperature data and the stored extraterrestrial radiation influenced equivalent evaporation data relating to the certain site a reference evapotranspiration value indicative of an estimation of the current watering needs of a certain reference vegetation at that certain site;adjusts the reference evapotranspiration value to account for both a user specified local adjustment factor and a type of vegetation at the site, wherein the local adjustment factor accounts for noted regionalization inaccuracies in the solely temperature/radiation calculated reference evapotranspiration value, to calculate a net evapotranspiration value indicative of an estimation of the current watering needs of the type of vegetation at that certain site;determines a watering program for the certain site; andimplements the determined watering program to have the processing unit issue commands for controlling the actuation of irrigation control valves at the site to replace lost water.