the present invention will now be described more fully with reference to the accompanying drawings in which preferred embodiments of the invention are shown and described . it is to be understood that the invention may be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein . rather , the applicant provides these embodiments so that this disclosure will be thorough and complete , and will convey the scope of the invention to those skilled in the art . like numbers refer to like elements there through . as illustrated initially with reference to fig1 , one preferred embodiment of the present invention includes a system 10 for controlling a prescribed application of chemicals from an aircraft 12 onto a ground target 14 . a first weather station 16 is positioned at a preselected altitude 18 and a second weather station 20 is positioned generally at ground level , preferably at or near the ground target 14 . a central communications station 24 , which may be carried within a mobile ground unit 25 or by way of example optionally in the aircraft 12 , communicates altitude and ground weather data with the first and second weather stations 16 , 20 and provides weather information to the aircraft 12 for effecting an appropriate distribution of chemicals from the aircraft to the ground target 14 based on real - time weather conditions at ground level 22 and at an aircraft altitude 26 . with continued reference to fig1 , an aerostat , herein described in one preferred embodiment comprising a helium gas balloon 28 , is carries the first weather station 16 for positioning it at the preselected altitude 18 . a winch 30 is positioned at ground level 22 and is operable with a tether 32 carried on a reel 34 of the winch at one end and attached to the balloon 28 at the other for controlling the altitude of the balloon . optionally , the first weather station may be carried by a tower of other similar structure for positioning it at the preselected altitude . with reference now to fig2 a and 2b , each of the first and second weather stations 16 , 20 comprise sensors 17 , 21 that may include a magnetometer configured as a directional compass 36 , an anemometer 38 for determining wind speed , a solid state or other appropriate temperature sensor 40 , a solid state or other appropriate humidity sensor 42 for measuring relative humidity , and a solid state aneroid or other pressure sensor / transducer 44 for altitude encoding , all of which provide weather related data to a processor 46 that processes input data and transmits the data through a two way rf transceiver / rf data link 48 . the processor 46 is also operable for communicating with the sensors 17 , 21 . for improved signaling and data transmission to the aircraft 12 , the first weather station 16 preferably includes an rf transmitter 50 employing spread spectrum processing . a global positioning receiver 52 is carried by the second weather station 20 , preferably positioned at ground level 22 proximate the ground target 14 for providing a reference position useful in programming a flight plan for the aircraft 12 . the weather data transmitted to the central station 24 for further may generally include temperature , relative humidity , altitude , wind speed and direction , data collection time , and data collection date . the aircraft 12 preferably includes a guidance system 54 , as illustrated with reference to fig3 , which may communicate with the weather stations 16 , 20 and the central communications station 24 . as illustrated by way of example , the guidance system 54 may operate with an onboard navigation system 56 for positioning the aircraft 12 proximate the ground target 14 and for following a prescribed flight pattern 57 , as illustrated by way of example with reference to fig4 a , over the ground target 14 during the distribution of chemicals . as earlier described with reference to fig2 a , the aircraft 12 receives data directly from the spread spectrum data transmitter 50 of the first weather station 16 by the receiver 60 of the guidance system 54 . as illustrated with reference to fig4 b and by way of example , weather conditions can dramatically affect the distribution of chemicals dropped from the aircraft 12 . the guidance system 54 operates to provide the prescribed flight pattern 58 and an appropriate modified pattern 62 , resulting from processing of weather data earlier described , as illustrated with reference , by way of example , to fig5 using processed weather data from the off aircraft stations 16 , 20 and flight pattern software which provides information from the processors 64 of the onboard guidance system 54 . with reference again to fig3 , the guidance system 54 provides precision guidance to a pilot of the aircraft 12 including obstacle awareness , flight recording and displays , meteorological data on a real - time basis and for a target area of interest . by way of example , the onboard guidance system 54 may provide tactical , strategic , and real - time support as follows : 1 . precision flight guidance 2 . obstacle awareness 3 . heads - up display 4 . in pilot &# 39 ; s field of vision 1 . status of spray off / on , proportional flow and spray system pressure 2 . error conditions - spray switch on , low flow , low pressure 3 . temperature inversion warning 4 . wind shift warning 5 . additional hardware displaying spray area , no spray zones , both optimized coverage and intended target ( wind corrected gridlines ) 6 . real - time wind speed , direction vectors provided 7 . statistical display of mission performance ( gallons sprayed , gallons remaining , acres treated , spray time , total mission time 8 . mission specific enunciators display on heads - up screen . in one operation and as illustrated with reference again to fig1 , the first weather station 16 is tethered by the balloon 28 at the preselected altitude 18 and generally near the target 14 for providing weather data to the aircraft 12 . the second weather station 20 is positioned at ground level 22 and generally below the first weather station 16 and at or near the target 14 for providing ground area weather conditions . the weather conditions at the preselected altitude , generally about 300 feet more or less , and the weather conditions at ground level are used to provide optimum conditions , by possibly modifying the planned prescription , for distributing the chemicals from the aircraft 12 at that specific time . in yet another operation , the balloon 28 is tethered from an initial altitude to a second altitude while monitoring and recording weather data through intermediate altitudes . by way of example , and with reference again to fig4 a and 5 , the prescribed flight pattern 58 is changed to the modified pattern 62 . the aircraft altitude may then be changed to an intermediate altitude for the chemical . by way of example , the aircraft altitude is changed from a planned 300 feet to a modified 250 feet ; the direction is modified ; and the swath 66 is modified , all based on the real - time conditions . preferable , the weather data from the altitude and ground positioned weather stations may be synchronized and include temperature , relative humidity , altitude , wind sped and direction , data collection time , and data collection date , and the data may be transmitted at least once every second . by way of further example , the fig4 depicts a typical spray mission where the approved target 14 is a 7 mile × 4 . 1 mile block . wind at 10 mph is in a direction perpendicular to the longest gridline . spray altitude is 300 ft . while the insecticide is released from the spray aircraft 12 over the target area , the 20 – 30 micron average particle is most likely deposited outside the target area . as illustrated with reference to fig5 , one spray mission may include an identical target area and weather condition . however , by optimizing the real - time weather data and mission correction controller , the altitude is lowered to 250 ft . and swaths are increased to 1300 ft . apart depositing the 20 – 30 micron particles in the target area . by way of further example , one embodiment of the weather statistics useful during mosquito control of chemical / insecticide application may be described by : use of 3 – 133 mhz microprocessors memory 32 – 300 mb sram 900 mhz spread spectrum transceiver 20 + mile range vacuum fluorescent graphics display 7 key back lit keypad user interface with 16 intensity settings redundant encoder user interface on front panel redundant pilots control yoke interface anti - glare display filter obstacle avoidance database on compact flash card pre - planned spray mission on compact flash card power 9 – 30 volts dc three 4 – 20 ma inputs one timer input ( pulse input ) on - board 8 - channel gps receiver rtcm 104 differential gps correction available two serial ports external light rs232 communication two analog inputs provide instantaneous real - time weather data at ground level . provide instantaneous real - time weather data at desired aircraft altitude . transmit all meteorology data every second to the data recorder . transmit all meteorology data every second to the personal computer . transmit all meteorology data every second to the application aircraft . provide location ( lat / long ) of the balloon to application aircraft every second . by way of yet further example , while deploying the balloon and when at a desired altitude , the aerial instrumentation may transmit weather data including time / date , altitude , temperature , humidity , and wind velocity by way of a 433 mhz rf transceiver to the ground instrumentation . the ground rf unit receives the aerial weather data and packages it with the ground weather data including the balloon location into a data pack , which is then transmitted back to the aerial unit through the 433 mhz rf unit . when the aerial instrumentation receives the entire weather data pack , it is then transmitted using the more powerful 900 mhz spread spectrum transceiver to either a ground receiver ( pc ) or to the aircraft in flight . this data is transmitted once per second . many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings . therefore , it is to be understood that the invention is not to be limited to the specific embodiments disclosed , and that modifications and alternate embodiments are intended to be included within the scope of the appended claims .
a chemical distribution control and guidance system operates for controlling the distribution of airborne product via an aircraft passing over a target . a weather station is positioned at various altitudes for use in determining an appropriate aircraft altitude for distributing the chemical to the target . a second weather station positioned near the target transmits weather data in real time to a central communications station and the aircraft for providing guidance in accurately , safely and effectively distributing chemicals onto the target .