Patent ID: 11954410
Assignee: DREXEL UNIVERSITY
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 2:
3. The method of claim 1, wherein the HSM algorithm comprises a MNS data structure that uses a pair of attributes, d(v) and f(v), for each cell v in the flow direction grid G, wherein d(v) denotes a discovery time of a respective cell and f(v) denotes a finish time of the respective cell,
wherein the HSM algorithm receives as its input a vertex as its staring cell from the flow direction grid G and in incremental fashion builds the boundary of a complete vector polygon representing the watershed Ω(v*) of all grid cells that drain through pour point,
wherein a polygonal chain is a closed lattice walk defined on a lattice L, a dual lattice for the flow grid G, and
wherein the correctness of the HSM algorithm relies on observations that every boundary grid cell of Ω(v*), with a valid flow direction value is guaranteed to have at least one adjacent neighbor that is not in the watershed that the cell it flows into.