Regional inventories of crop acreage based on area frame sampling and satellite images
An operational method has been developed for regional inventories of crops or other land use, based on area frame sampling and high resolution satellite images. The main software used to carry out the estimation method is operational, but not user friendly. A functional analysis has started for an in depth renewal of the software. A working scheme to produce frame stratifications has been developed. Support is being provided to digitizing segment drawings from field survey through television tracking system. A study has been undertaken to establish a working scheme for image classification and correction of estimates. The main conclusions of the comparisons of results are that a sample of n TER-UTI segments of 36 points on a squared grid covering 1800 m by 1800 m, gives better precision than a sample of n complete segments of 700 m by 700 m, involving field drawing and digitizing. However, point sampling is less suitable than segment sampling for matching with remote sensing. The relative efficiencies of regression correction of area estimates by remote sensing on point segments is much lower than that on complete segments. In most regions, samples have been drawn with a systematic aligned method. A method is being studied to improve the estimation by considering clusters along the sampling blocks and permutations within the blocks. A subsample of the segments of the ground survey is being revisited several times during the year to obtain a fast assessment of the crop rotation, state of crops and area evolution.
Record Number: 12411 / Last updated on: 1995-06-19
Collaboration sought: Information exchange/Training