WCPS-Manual / unaryArithmeticExpr
The unaryArithmeticExpr element specifies a unary induced arithmetic operation.
C1 be a coverageExpr
The server shall respond with an exception if one of the coverage's grid cell values or its null values is negative.
The following coverage expression evaluates to a float-type coverage where each cell value contains the square root of the sum of the corresponding source coverages' values.
sqrt( C + D )