Therefore, a system of observation equations can be set up. The tidal parameters can be estimated by forming a system of normal equations and then solving by least-squares. Cosmos, the Cray T3D located at JPL, was used to develop the parallel estimation algorithm for the ocean tide model. A simple way to parallelize the estimation algorithm would have been to allow each processor to work on an independent record of input data, using the sequential BLAS routines. For this problem size, the minimum number of processors required to generate the normal matrix is approximately 64.
Several threads run in parallel, each operating on an independent data record.
The parallel estimation algorithm automatically calculates the block size of the normal matrix and the number of threads possible on a given partition.