  The goal of this study was the evaluation of agriculture parcel area
measurement accuracy on Cartosat-1 imagery, and the determination of the
technical tolerance appropriate for measurement using photointerpretation
techniques. A further objective was to find out the influence of image type,
land cover or parcel size on the area measurement variability. In our
experiment, five independent operators measured 185 parcels, 3 times, on each
image. Next, the buffer width, calculated as the difference between measured
and reference parcel area, was derived and was the subject of statistical
analysis. Prior to verifying the normality of the buffer widths, a detection of
anomalous measurements is recommended. This detection of outliers within each
group of observations (i.e. parcels) was made using the Jacknife distance test
on each type of imagery (Cartosat Aft, Cartosat Fore). Then, the General Linear
Model procedure to identify major significant effects and interactions was
followed by analysis of variance to ease the interpretation of the variability
observed of the area measurement. Finally, two different parameters,
reproducibility limit and critical difference, were calculated to make
comparison with other sensors like digital aerial orthophoto in this study
possible. The repeatability limits gave the acceptability difference between
two operators when measuring the same parcel. For orthophoto this value reached
2.86m, on Cartosat-1 5.17m and 8.76m for Aft and Fore image respectively.
