Method and apparatus for irrigation control using evapotranspiration

A method of controlling irrigation sprinklers using broadcast Evapotranspiration data, comprising the steps of:

• broadcasting an Evapotranspiration data signal to a collection of receivers coupled to a plurality of irrigation flow controllers, said Evapotranspiration data signal containing a plurality of coded Evapotranspiration zone identifiers and corresponding coded Evapotranspiration values, each of said collection of receivers including means for storing an Evapotranspiration zone reference and a crop adjustment value;
• receiving said Evapotranspiration data signal;
• decoding said Evapotranspiration data signal to produce a plurality of decoded Evapotranspiration zone identifiers and corresponding Evapotranspiration values;
• comparing each of said decoded Evapotranspiration zone identifiers with said Evapotranspiration zone reference;
• and
• adjusting an irrigation flow quantity of particular ones of said plurality of flow controllers having said Evapotranspiration zone references matching a particular one of said decoded Evapotranspiration zone identifiers to about equal a product of a particular one of said Evapotranspiration values corresponding to said particular one decoded Evapotranspiration zone reference and said crop adjustment value.

A system for controlling irrigation sprinklers using broadcast Evapotranspiration data, comprising:

• means for broadcasting an Evapotranspiration data signal to a collection of receivers coupled to irrigation flow controllers, said Evapotranspiration data signal containing broadcast coded Evapotranspiration zone identifiers and broadcast coded corresponding Evapotranspiration value, each of said collection of receivers including means for storing a Evapotranspiration zone reference and a crop adjustment value;
• means for receiving said Evapotranspiration data signal;
• means, coupled to said receiving means, for decoding said Evapotranspiration data signal to produce a plurality of decoded Evapotranspiration zone identifiers and corresponding Evapotranspiration values;
• means, coupled to said decoding means, for comparing each of said decoded Evapotranspiration zone identifiers with said Evapotranspiration zone reference;
• and
• means, coupled to said comparing means, for adjusting an irrigation flow quantity of said plurality of flow controllers having said Evapotranspiration zone references matching a particular one of said decoded Evapotranspiration zone identifiers to about equal a product of a particular one of said Evapotranspiration values corresponding to said particular one decoded Evapotranspiration zone reference and said crop adjustment value.

A method of controlling irrigation sprinklers by receiving and processing FM subcarrier broadcasts of Evapotranspiration data to control automatically a set of irrigation sprinklers, said method comprising the steps of:

• directly broadcasting an Evapotranspiration data signal from a transmitter;
• receiving said Evapotranspiration data signal at a receiver;
• coupling said Evapotranspiration data signal from said receiver to an irrigation flow controller having a preset duty cycle for watering;
• and
• adjusting said preset duty cycle responsive to said Evapotranspiration data signal to provide an adjusted duty-cycle signal.

A system for regulating sprinkler controllers using direct broadcast of Evapotranspiration data, said system comprising:

• means for directly broadcasting an Evapotranspiration data signal;
• receiving means for receiving said Evapotranspiration data signal;
• an irrigation sprinkler controller having a preset duty cycle for watering;
• means for coupling said Evapotranspiration data signal from said receiving means to said irrigation sprinkler controller;
• means for adjusting in said irrigation sprinkler controller said preset duty cycle for watering responsive to said Evapotranspiration data signal to provide an adjusted duty-cycle signal, whereby said irrigation sprinkler controls the amount of water sent to plants according to said adjusted duty-cycle signal.

A system for directly broadcasting selected portions of an Evapotranspiration database to a collection of receiving and sprinkler-controlling units distributed over a geographic area, each receiving and sprinkler-controlling unit being coupled to at least one irrigation sprinkler, said system comprising:

• means for directly broadcasting a stream of encrypted Evapotranspiration data;
• a plurality of irrigation sprinkler controllers, each of said controllers having a preset duty cycle for watering;
• a plurality of receiving means for receiving said encoded Evapotranspiration data signal, each of said receiving means being coupled to at least one of said irrigation sprinkler controllers, and each receiving means including means for storing a preset Evapotranspiration zone reference and for storing a preset crop adjustment value;
• each of said receiving means also including means for decrypting said encrypted irrigation control signal into a broadcast Evapotranspiration zone identifier and a broadcast corresponding Evapotranspiration value;
• each of said receiving means coupled to irrigation sprinkler controller means including means of comparing said broadcast Evapotranspiration zone identifier with said preset Evapotranspiration zone reference such that each of said sprinkler controllers is selectively responsive to a corresponding one of said Evapotranspiration values of one of said zone identifiers;
• means for coupling said Evapotranspiration data signal from each of said receiving means to said irrigation sprinkler controllers;
• means for adjusting in said irrigation sprinkler controllers said preset duty cycles for watering responsive to said Evapotranspiration data signals and also responsive to said preset crop adjustment value to provide adjusted duty-cycle signals, whereby said each of said irrigation sprinkler controllers controls the amount of water sent to plants according to said adjusted duty-cycle signal.

A method of distributing Evapotranspiration information for a plurality of Evapotranspiration zones over a distributed geographic area for automatic adjustment of watering intervals for irrigation flow controllers, comprising the steps of:

• compiling a database of a plurality of Evapotranspiration values for each of the plurality of Evapotranspiration zones;
• matching each of said plurality of Evapotranspiration values with its corresponding Evapotranspiration zone to produce a set of Evapotranspiration zones having corresponding Evapotranspiration values;
• and
• broadcasting periodically said set of Evapotranspiration zones with corresponding Evapotranspiration values.