Several studies have been carried out to find an appropriate method to classify the remote sensing data. Traditional classification approaches are all pixel-based, and do not utilize the spatial information within an object which is an important source of information to image classification. Thus, this study compared the pixel based and object based classification algorithms using RapidEye satellite image of Eti-Osa LGA, Lagos. In the object-oriented approach, the image was segmented to homogenous area by suitable parameters such as scale parameter, compactness, shape etc. Classification based on segments was done by a nearest neighbour classifier. In the pixel-based classification, the spectral angle mapper was used to classify the images. The user accuracy for each class using object based classification were 98.31% for waterbody, 92.31% for vegetation, 86.67% for bare soil and 90.57% for Built up while the user accuracy for the pixel based classification were 98.28% for waterbody, 84.06% for Vegetation 86.36% and 79.41% for Built up. These classification techniques were subjected to accuracy assessment and the overall accuracy of the Object based classification was 94.47%, while that of Pixel based classification yielded 86.64%. The result of classification and accuracy assessment show that the object-based approach gave more accurate and satisfying results

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Hydrographic surveys define shorelines and depths of lakes, streams, oceans, reservoirs, and other bodies of water. Sea surveying is associated with port and offshore industries and the marine environment, including measurements and marine investigations made by ship-borne personnel. In addition, accurate measurement and modelling of hydrographic information is important to control waterways boat services with existing roadway transportation services. This paper attempts an empirical analysis of hydrographic data to simulate waterway navigable route within Lagos Lagoon with a minimum under-keel clearance that must be maintained by vessel transiting a port as well as berthing. The field investigation was conducted between September 2015 and March 2016 to determine river bed topography with the deployment of DGPS receivers, Single beam SDE 28S echo sounder, speed boat, tidal observation and reduction. Hypack 2008 and Arc GIS software was used for data sorting, extraction and processing. It was observed that depth within the project area ranges between 0.0m to 14.82m when referred to the Lagos datum. Furthermore, waterway navigable chart was developed based on prevailing river bed topography along the study corridors as well as passenger ferry draught constraint. From this study, derived depths were analysed in form of graphs and charts that provides a suitable framework to support ferry transportation services within Lagos Lagoon as a complimentary mode to the dominantly depended road transportation services. Therefore, periodic hydrographic survey of the navigable routes is recommended specifically to identify possible channel accretion.

Attempt has been made in this research to investigate geometric quality of an Unmanned Aerial

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