EstNet architecture. EstNet comprises four parts: input module, PRSE module, GRU module, and output module, as shown in panels 1–4. Panel 5 illustrates two types of information presented in spectra: the local spatial information of a specific spectral line and the global dependencies between different absorption lines. Panel 6 describes the structure of the PRSE block, which determines the depth of EstNet. Panel 7 details the internal structure of the GRU cell, a neural component with memory capabilities.