Assessment of digital camera for mapping stream using close range photogrammetric technique

Photogrammetry is a technique that can be used for topographic mapping and many countries in the world used this technique for mapping. It also can be used for non-topographic mapping such as mapping facade of building, monument, historical building, human body and others using a technique known as close range photogrammetry. In this technique usually a metric camera is used. However, with the advancement in digital technology, it has embraces the technology where digital camera can be used for acquiring photograph of the object of interest. Usually the distance from the camera to the object is within few centimetres and up to 300 meters. Today, there are many make and models of digital camera ranging from low cost to affordable cost. The cost of the digital camera is based on the technology used, resolution of the digital image, capabilities and other factors. Due to the various make, model and capabilities the user of digital camera need to assess it if accurate measurement is required and produce output from the photogrammetric technique. In developed countries, digital camera (i.e in the form of metric and non-metric camera) has been utilized together with close range photogrammetric technique for various applications and fields including mapping stream or river. The purpose of the study is to assess digital camera in mapping stream and determine the accuracy of measurement using close range photogrammetric technique. This study is divided into mapping stream model and real stream. The main output of this study is the orthophoto, The results showed that the computed root mean square error (RMSE) for the model stream is ±0.667m and ±0.619m using metric camera and non-metric camera respectively. While the computed RMSE for the real stream is ±0.444m and ±0.348m using metric camera and non-metric camera respectively. From this study, the results for the real stream are better than the stream model. Also the finding of this study demonstrates that both the metric digital camera and non-metric digital camera can be used for mapping stream.