Estimation of areas from remote sensing sources where the grid network is used, samples will be selected from the 4 km grid. The intent is to increase sample precision but, unless the correlation between the photo and field estimates is good, the method may not be cost effective. When the NFI data comes on stream it is clearly suited to providing national and ecozone summaries of the listed attributes. The NFI design is ideally suited as a basis for calibrating national coverage data from remote sensing platforms due to it s design. The main contribution of remote sensing is the provision of an objective stratification of the NFI plots.
Any survey runs the risk of poor representation of the plots.
Adding a remote sensing component effectively removes any bias that the NFI plots inadvertently may have introduced in reporting on totals. These units do contain sufficient diversity to allow a calibration on a regional scale for all listed attributes extracted from the remotely sensed images. This constitutes real progress and improvement over existing data for national reporting. Average patch size information is readily available from the survey although not explicitly listed. Plant lists from ground plots will, over time, provide important information on trends in species diversity.