| Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 103 === The precision of spatial data acquired by vehicle-based Mobile Mapping System (MMS) depends highly on the precision of the positioning equipment. After Global Positioning System (GPS) is not able to receive enough satellite signals for a while, the error propagation in positioning of IMU will affect the precision of spatial data. There are many adjustment models aiming to reduce the error, but there are few software tools that are flexible enough to support the operation of adjustment.
In this thesis, a software framework is developed for data processing in MMS, called ntuMMF (NTU Mobile Mapping Framework). The architecture of ntuMMF is pipes and filters. ntuMMF consists of six major components: source, reader, filter, sink, writer and mapper. The processing pipeline is a composite of these components. These components have the same interface, so the new processing pipeline can be easily created by adding a new component. In addition, ntuMMF formulates the operating procedure of these components to make sure the processing pipeline can work seamlessly.
A toolkit for data processing in MMS, called MMTK (Mobile Mapping Toolkit), is developed based on ntuMMF. MMTK supports many common files’ formats in MMS; it also provides the basic data processing functions. Some templates are provided for developers to implement the algorithm rapidly.
Three different examples are used to demonstrate the flexibility of the proposed framework and toolkit. The first example shows the flexibility of the combination of the pipeline. Although there are only three components in the processing pipeline, the new processing pipeline can be created by replacing a component with different functions. As a result, a three-component pipeline can solve most of the requirements from the first example.
The second example shows the flexibility of the operation of the pipeline. The request-intensive service in the example can be implemented by calling the trigger function of the pipeline. Because the pipeline can work partially, the time of handling user’s requests can be very short.
The third example not only shows the flexibility of the operation of the pipeline as the second example, but also demonstrates the versatility of ntuMMF. The type of data in the third example is different from the data in the above examples, but the data processing procedures remain identical.
The contribution of ntuMMF is twofold. First, by encapsulating the data processing procedure, the process flow becomes more flexible for reuse. Second, the versatility of the framework unifies the procedure of data processing in MMS, and it demonstrates the development procedure step by step.
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