Sharpening of Sentinel-2 imagery for updating thematic layer of base maps

Abstract

Currently, the Geospatial Information Agency of Indonesia has provided a relatively complete Base Maps RBI (Rupa Bumi Indonesia) on the map scale of 1/25,000 to 1/50,000. This Base maps data that can be downloaded for free via the <a href="https://tanahair.indonesia.go.id/">https://tanahair.indonesia.go.id/</a>. However, some of the RBI Maps were produced in 2001. Therefore, it is necessary to update the Maps. The existence of access to medium-resolution image data such as the Sentinel-2 satellite imagery can be a low-cost solution. However, the Sentinel-2 imagery should be enhanced for better visual interpretation. This research tries to sharpen Sentinel-2 imagery. The results can be used to update the existing themes in the RBI Map. This study takes the case of the Sleman district in the province of Yogyakarta area which is developing quite rapidly. The Sentinel-2 level 2A data from 2 epochs was used for sharpening. The process of sharpening is carried out with the concept of upscaling and superposition operator using two-epoch images. The procedure has succeeded in sharpening imagery for visible interpretation of selected band. After sharpening imagery, the thematic object's shape can be seen clearly so that visual interpretation is more reliable to use. Furthermore, band combination operators and the color composites formation are carried out to enhance the selected thematic objects more clearly. The process of updating the RBI map is done by visual interpretation. The road network theme data on the RBI map is used as a geometric and updated reference. So that the updating process is carried out in one block area that does not cross the road line. Sharpening of Sentinel-2 imagery has opened up opportunities to apply visual interpretation to update thematic objects on RBI maps at a 1/25,000 scale.