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This paper explains the process carried out in identifying the significant role of NDCDB in Malaysia specifically in the land-based analysis. The research was initially a part of a larger research exercise to identify the significance of NDCDB from the legal, technical, role and land-based analysis perspectives. The research methodology of applying the Delphi technique is substantially discussed in this paper. A heterogeneous panel of 14 experts was created to determine the importance of NDCDB from the role standpoint. Seven statements pertaining the significant role of NDCDB in Malaysia and land-based analysis were established after three rounds of consensus building. The agreed statements provided a clear definition to describe the important role of NDCDB in Malaysia and for land-based analysis, which was limitedly studied that lead to unclear perception to the general public and even the geospatial community. The connection of the statements with disaster management is discussed concisely at the end of the research.

This paper explains the process carried out in identifying the legal significance of National Digital Cadastral Database (NDCDB). The research was initially a part of a larger research exercise to identify the significance of NDCDB from the legal, technical, role and land-based analysis perspectives. The research methodology of applying the Delphi technique in this study is substantially discussed in this paper. In pursuit of applying the Delphi technique, a heterogeneous panel of 14 experts was formed among cadastre, land and GIS domain experts. Four statements on the legal significance of NDCDB in Malaysia specifically in Peninsular Malaysia and Federal Territory Labuan were established after three rounds of consensus building. The agreed statements provide a clear definition to describe the significance of NDCDB in the legal point of view, which was previously vague and confusing to the general public and even the geospatial community.

The purpose of this paper is to evaluate the orthometric height derived by combination of Global Navigation Satellite System (GNSS) data and global geoid height information over Peninsular Malaysia. The global geoid height information is derived from recent Global Geopotential Models (GGMs); combined and satellite-only solution. Total numbers of 131 GNSS points were observed and computed the orthometric height on the existing Standard Benchmark (SBM). Furthermore, the comparison between derived orthometric height and existing levelling value is evaluated. From the analysis of the results shows that the differences in term of the root means square between derived orthometric height and existing levelling value over Peninsular Malaysia in within range ±21.8cm and ±26.9cm. The datum bias between global and local vertical datum is within range −1.220m and −1.313m.

An Acoustic Ground Discrimination System (AGDS) able to extract an information of the nature of the feature on the seabed. AGDS compared with satellite imagery are abnormally and rarely used in tropical environments although is easier to operate and friendly produces an amount of digital data. This study aimed to assess acoustic survey of sea-bed benthic classes using RoxAnn ™ AGDS in the north of Langkawi Island. Sea-bed benthic classes were categorized into six levels of classes using hierarchical classification of field data. Using the independent data, classes and signal of the nature seabed were identified (library) of RoxAnn ™ created and represent by number coding. These accuracies are assumed are conservative because of constraints during this study including quantitative data for discriminating class types. The class type changes between AGDS and accuracy assessments surveys and environments condition. Despite these limitation, AGDS accuracy level are high and more accurate compare to those satellite achievement and it has advantages including greater water penetration and unaffected from cloud cover. An Acoustic data are useful tools for mapping the tropical habitat and complementary to satellite data.

A numerical analysis comparison has been made between derived geoid height from geopotential models and existing regional gravimetric and fitted geoid models. This study is part of an analysis of optimal global geopotential models to determine a seamless precise geoid model. A total of ten (10) recent global geopotential models were combined with satellite-only solutions in this study. Results from the statistical analysis show that EGM2008 and EIGEN-6C provide accurate information on deriving geoid heights for combined solutions, and GOCO01S is useful for satellite-only solutions.

In recent years, Global Positioning System (GPS) receivers have been placed on buoys to determine the height of sea surface. GPS buoy always have an advantages over traditional techniques in measuring water level, which is their ability to determine heights relative to an absolute reference frame. There are scenarios where it is not practical or difficult to install a conventional tide gauge especially in inaccessible area like mangrove forest. Since traditional method being used to measure the sea level, large number of tide gauge required to be maintained and observed at the same time. This required manual observation and a number of labours which has lead to the lack of efficiency in data management, processing and economic. This paper would review on the development of GPS buoy design with possible application of it, as well as the results achieved by previous studies. Proposed method of efficient water level monitoring system with technical aspect that should be taken into account would be discussed. The paper would sum up with some discussion on GPS buoy implementation prospect in Malaysia.

Recently, International Center for Global Earth Models (ICGEM) published more than 50 Global Geopotential Models (GGMs). These GGMs plays an important role in a determination of a precise geoid model. Nowadays, some of the models offer high accuracy and better resolution of the gravity field. In this study, several recent GGMs derived from satellite-only (eg. EIGEN) and combined (eg. EGM2008) will be used. Gravity anomalies derived from selected GGMs are analyzed and compared with gravity anomalies derived from terrestrial gravity observation over West Malaysia (WM). The comparison and the results of selected GGMs is shown with the residual statistic. From the results, gravity anomalies derived from combined solution Earth Gravity Model (EGM2008) with the spherical harmonic coefficients up to 2190 is the most suitable model can be use as a reference over West Malaysia.

Elevation-storage curve is a technical illustration of the reservoir volumes at corresponding reservoir levels. It is an important element for any reservoir operation in order to provide the knowledge of water availability to engineers, managers, and regulators. This curve usually prepared by dam consultants where the values are estimated by analyzing available topographic maps and pre-impoundment surveys. Many reservoirs in Malaysia have not been resurveyed in the decades since their construction. Hence, as sediment deposits gradually reduce reservoir capacity over time, and because the original reservoir volume were limited by the accuracy of the existing topographic maps, estimates of the current storage plotted in the elevation-storage curve for reservoirs not re-surveyed since their construction are subject to error. This study put forward the positioning data acquisition through hydrographic survey in order to determine accurate reservoir volumes. The positioning data are then processed in Terramodel software to get the volumes at corresponding reservoir levels. An information system called as ReTISRO is developed in this study for generating the elevation-storage curve using the volumes data produced by Terramodel, receiving real time tidal data from the tide gauge via radio link, and displaying the real time elevation and storage of the reservoir on its interface. The outcome of the study contributes a fully digital high accuracy information system that can be applied by any reservoir operation. It offers a reservoir storage monitoring with continuous data displaying and recording that can be very useful for further water management analyses.