Evaluation of Luojia 1-01 Nighttime Light Imagery for Built-Up Urban Area Extraction: A Case Study of 16 Cities in China

On June 2, 2018, the Luojia 1-01 (LJ1-01) nighttime light satellite was launched from China with a spatial resolution of 130 m at nadir, which is a significant improvement over the resolutions of previous nighttime light satellites. However, few studies have focused on the applications of LJ1-01 imagery. This letter aimed to evaluate the potential of utilizing LJ1-01 data to extract built-up urban areas in comparison with Visible Infrared Imaging Radiometer Suite (VIIRS) day-night band (DNB) data by conducting a case study of 16 cities involved in the Belt and Road Initiative in China. The built-up urban areas of the 16 cities were extracted by thresholding segmentation in reference to administrative statistical data, and 30-m-resolution artificial impervious data were adopted as the benchmark (ground truth). Qualitative and quantitative assessments were implemented for an evaluation, revealing that the built-up urban areas extracted by LJ1-01 data outperformed the areas extracted by VIIRS DNB data. We argue that these improvements originate from the superior spatial resolution and image quality of LJ1-01 over its predecessors. The LJ1-01 data presented excellent suitability for the extraction of built-up urban areas at the city scale, and hence, these data may be further applied to other related investigations.