Background
These are the statistics generated from the DEA Water Observations (Water Observations from Space) suite of products, which gives summaries of how often surface water was observed by the Landsat satellites for various periods (per year, per season and for the period from 1986 to the present).
Water Observations Statistics (WO-STATS) provides information on how many times the Landsat satellites were able to clearly see an area, how many times those observations were wet, and what that means for the percentage of time that water was observed in the landscape.
What this product offers
Each dataset in this product consists of the following datasets:
Clear Count: how many times an area could be clearly seen (i.e. not affected by clouds, shadows or other satellite observation problems)
Wet Count: how many times water was detected inobservations that were clear
Water Summary: what percentage of clear observations were detected as wet (i.e. the ratio of wet to clear as a percentage)
As no confidence filtering is applied to this product, it is affected by noise where misclassifications have occurred in the input water classifications, and can be difficult to interpret on its own. The confidence layer and filtered summary are contained in the Water Observations Filtered Statistics (WO-FILT-STATS) product, which provides a noise-reduced view of the all-of-time water summary.
WO-STATS is available in multiple forms, depending on the length of time over which the statistics are calculated. At present the following are available:
WO-STATS:statistics calculated from the full depth of time series (1986 to present)
WO-STATS-ANNUAL:statistics calculated from each calendar year (1986 to present)
WO-STATS-NOV-MAR:statistics calculated yearly from November to March (1986 to present)
WO-STATS-APR-OCT:statistics calculated yearly from April to October (1986 to present)