Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: July 18, 1999
Publication Date: August 1, 1999
Citation: THOMSON, S.J., HANKS, J.E., SASSENRATH COLE, G.F. REMOTE SENSING SYSTEM FOR AGRICULTURAL SPRAY PLANES - PRELIMINARY FIELD OBSERVATIONS. ASAE ANNUAL INTERNATIONAL MEETING. 1999. Paper No. 99-1137. Interpretive Summary: Remote sensing systems are used to detect crop and soil conditions from the air so the farmer can better manage the crop for maximum yield and profit. Systems in use today include satellite-based and aircraft-based systems. On aircraft, on-board systems take images of a field to determine if the crop needs water or nitrogen, or to detect the presence of weeds in the field. The farmer can also determine what soil types there are so he/she can manage the crop differently within those zones, and determine yield at the end of the season so areas of low yield can be managed differently. Conventional aircraft cannot fly low enough to distinguish fine features and alternatives need to be found. A remote sensing system for a spray plane was developed to help solve this problem. This system has the potential of delineating features at very low altitudes. For example, weeds may be detected and distinguished from one another so a specific herbicide can be applied only to parts of the field that need it. This will save money and reduce amount and chance of spray drift to non-target areas. This preliminary study evaluates image quality from the remote sensing system used on a spray plane. Three different global positioning systems (GPS) that determine field position (matched to each image) were also evaluated. Crisp images were obtained from 7 m (25ft) to 450 m (1500 ft) altitude. One GPS system worked the best of the three systems tested and was accurate in determining the proper field position.
Technical Abstract: An image-based remote sensing system was configured on an agricultural spray plane. The system uses video mapping hardware for continuous geo-referencing of images obtained by digital video. A differential GPS was used in parallel with the plane's GPS and was dedicated to the remote sensing system. GPS data brought to the video mapping hardware provided continuous information on position to video tape as images were obtained. Tests were conducted to evaluate the quality of data obtained by three GPS configurations used with the video mapping system and to subjectively evaluate the quality of images obtained at various heights, with and without optical filters. Data from each of the GPS systems were compared with output from the plane's Satloc GPS system. When the GPS system was forced to use OmniStar differential correction, it performed the best of all configurations with fewest problems updating a position fix. Clear images were obtained with the remote sensing system from 7m to 450m altitude.