Looi Kam Seng
Director of Survey
Department of Survey and Mapping Malaysia
Biography27 years experience in survey and mapping with 21 years in cadastral survey, 3 years in survey management and 3 years in topographical mapping. Subject Matter Expert in cadastral survey.AbstractCadastral Database Accuracy EnrichingPreviously, the cadastral database was in hardcopy map, then converted into digital format and subsequently updated seamlessly in eKadaster project. With the growth of geospatial based technology namely the Geographical Information System (GIS) and Global Navigation Satellite System (GNSS) the accuracy of the legacy cadastral database is inevitable. Principally, these legacy datasets have low positional accuracy caused by limitation of traditional measurement, adjustment technique and technology changes over time. In the past, absolute accuracy requirement was not precedence where only relative accuracy was emphasized. Since traditional cadastral measurement methods are based on relative positioning, the error propagation that exists in the cadastral database is inescapable. The management of cadastral database is very complex where it involves various categories of data accuracy because the source of legacy cadastral database comes from the different classes of observation accuracy. The objectives of this research are to enhance the accuracy of the cadastral database through the establishment of high accuracy Positional Reference Mark, towards the improved database accuracy, to perform angular based observation in cadastral database adjustment, and updating cadastral SQL database. Hence, the methodology involves devising standard operating procedure for GNSS control network establishment and enhancement, for cadastral data reduction and traverse survey adjustment as well as block adjustment, and for cadastral traverse survey and certified plan conversion from bearing to angle format. To achieve this, an extensive study on stochastic model will be carried out to ensure the expected outcomes of the improved cadastral database accuracy to prevail. Indirectly this will minimize the effects of low-quality observations on cadastral block adjustments. For that, the expected outcomes will be a new network for primary control network and block control network, a proposed stochastic model for observation in cadastral block adjustment, a new data acquisition and reduction procedures and perform a complete information for cadastral SQL database. On top of that, this research will speed up and contribute to the development involving land acquisition, land development, strata survey, underground survey and 3D Cadastral. In conclusion, based on the feedback from the users, the precision and accuracy of current National Digital Cadastral Database (NDCDB) is vary and inconsistent. Therefore, to solve these issues, the Department of Survey and Mapping Malaysia (DSMM) has adopted a new approach to the management of cadastral plans where the cadastral database is not only in digital format but also has good absolute positional accuracy.