Data processing of hydroacoustic data as support to mapping and characterization of seafloor Giankarlo R F.Fernandes de Oliveir, Mary Lucia S. Nogueira, Helenice Vital, Josibel Gomes de Oliveira Junior Federal University of Rio Grande do Norte Natal – Brazil giankarlocash@gmail.com; marylsnogueira@yahoo.com.br; helenice@geologia.ufrn.br, oliveirajr@ufrnet.br , Abstract: This work aims to present a processing flow designed for shallow seismic data acquired in the northern continental shelf of Rio Grande do Norte State, adjacent to Areia Branca city. This area was choose because of the presence of an important incised-valley system, between depths of 15 m to 25m. The understanding of the formation and cenozoic filling of incised valleys has contributed more and more to studies with similar reservoirs of oil and gas. The data were acquired with a sub-bottom profiler type chirp, using small boats. The signal penetration reached approximately 45m with subsurface water depths of up to 40m. During activities were acquired information of parameterization software acquisition, software and processing tools. All data were integrated with GIS (Geographic Information Systems). Processing consisted in the adaptation of coordinate system, spectral analysis, optimization of the process of removing the water depth, application of low-pass filters and FK, according to the need of each section and bathymetric correction. The results revealed a smoothing effect of the waves, noise attenuation and multiple best contrasting the different types of reflectors thus enabling the identification of different seism facies in existing sections. keywords: shallow seismic; shelf; sub-bottom profile; incised- valley; bathymetric correction I. INTRODUCTION Incised valleys were identified in the western portion of the northern continental shelf of the State of the Rio Grande do Norte [1]. In the study of modern incised valleys, the data of high resolution seismic are of great usefulness for characterization of sismo-facies. [2]. In this work we present a processing flow chart for high resolution seismic data acquired in the area of the incised valley Apodi-Mossoró (Fig. 1). We select for this work a passage of one of the lines of acquisition, located in the portion of the Continental Shelf, in front of Areia Branca City. The northern Continental Shelf of the Rio Grande do Norte, is the immersed extension of the Potiguar Basin being characterized as a mixed platform composed by a covering of siliciclastics and carbonatics sediments [3]; [4]. The aim of developing a flow chart for this type of processing is optimize the process of interpretation. Fig. 1. -Location map showing the portion of the seismic line presented in this work. II. METHODOLOGY Data acquisitions were carried out on small boats with a sub-bottom profiler X-Star type Chirp, made by EdgeTech (Figure 02). Penetration in the study area reached 45m in subsurface. These data were integrated with satellite images in the software ArcMap of the package ARCGIS. The high resolution data were processed using the software Reflexw. Common to this type of acquisition is the presence of an interference in the geometry of the fact, when the tide conditions were owed on the day of the acquisition. Because of this, there was necessary a flow chart that was corresponding to such conditions. Fig.2. 2.A) sub-bottom profiler X-Star; 2.B)X-Star being placed in water; 2.C)X-Star the time of acquisition. PIBIC (CNPq), SISPLAT (REDE 05/FINEP/CNPQ/PETROBRAS), Ciências do Mar 207-2010 (CAPES), PROBRAL 337-10 (CAPES/DAAD), Grant PQ 303481/09-9 (CNPq) and PRH22/ANP/MCT (FINEP/ CTPETRO/ PETROBRAS). IEEE/OES RIO Acoustics 2013 978-1-4799-0362-7/13/$31.00 ©2013 IEEE