The acquisition of satellite images over a wide area is often carried out across seasons because of satellite orbits and atmospheric conditions (e.g., cloud cover, dust, etc.). This results in spectral mismatch between adjacent scenes as the sun angle and the atmospheric conditions will be different for different acquisitions. In this work, we developed an approach to generate seamless mosaics using Scale-Invariant Features Transformation (SIFT). In this process, we make use of the overlapping areas between two adjacent scenes and then map spectral values of one imagery scene to another based on the filtered points detected by SIFT features to create a seamless mosaic. We make use of the Random Sample Consensus (RANSAC) method successively to filter out obtained SIFT points across adjacent tiles and to remove spectral outliers across each band of an image. Several high resolution satellite images acquired with WorldView-2 and Dubaisat-2 satellites, and medium resolution Sentinel-2 satellite imagery are used for experimentation. The experimental results show that the proposed approach can generate good seamless mosaics. Furthermore, Sentinel-2’s level 2A (L2A) product surface reflectance data is used to adjust the spectral values for color consistency.

This communication introduces the National Space Science and Technology Center (NSSTC), established at the United Arab Emirates University (UAEU) in 2016, its main activities and its first satellite project. NSSTC primary research and development areas are: Remote sensing, Space and planetary science, real time embedded systems, in-situ resource utilization, In-orbit propulsion as well as Space communication and satellite based navigation. The latter will be the focus of this communication and in particular the Radio Frequency (RF) signaling technology satellite, GNSSaS. This is a 6U Cubesat that will be launched in 2021 into a 500 -600 km sun synchronous orbit. It will include an Global Navigation Satellite System (GNSS) augmentation RF signaling demonstrator payload, GNSS reflectometry payload for remote sensing, and a UHF/VHF experiment for measuring the effects of the ionosphere on these RF frequencies. The paper will describe the objectives of this cubesat in more detail and how it ties up with the rest of NSSTC activities.