In common with other seismic data compression methods that are described in the literature, the method that is proposed here is a transform based method. These methods all employ some fast data transformation, which focusses the coherent data energy, a quantization step in which accuracy is sacrificed for the sake of higher compression ratios and, finally, an encoding step. The proposed method employs a local trigonometric transformation with smooth overlapping windows. This transformation is better suited to capture the characteristics of seismic data than for instance the wavelet transformation. In addition, the structure of the transformation enables easy access to the data in the compressed domain.
Small subsets can bedecompressed independently from the bulk of the compressed data.
Compression can be viewed as one of many sources of noise in seismic data. Compression noise should therefore not be assessed on its own but related to other noisy components. It is consequently important to use the compression noise level rather than the compression ratio as the point of departure. The allowed compression noise level is then an input parameter rather than the compression ratio. If they are transmitted to be processed a refraction mute, FK-filtering etc may be in order.