Comparative analysis of reflectance values on sentinel-2A image with field spectroradiometer in mangrove forest on East Coast Lampung

The study’s objective is to assess the value of measurements made using a spectroradiometer and sentinel-2A image reflectance. This study uses Sentinel-2A imagery to produce reflectance valuesby processing them on the Google Earth Engine. Data collection was carried out in this study, there were 24 sample points spread across parts of the east coast of East Lampung. Taking these sample points using a spectroradiometer where the sample is a mangrove canopy. The results of taking the points in the field will be correlated with the results of the values in the Sentinel-2A Image, taking the points in the field 2 times to get the average reflectance value. Transformation of the NDVI and EVI vegetation indices is used as the research methodmeasurements with a field spectroradiometer. The results showed that the reflectance value on the field spectroradiometer tends to be higher than on the Sentinel 2A image. The resulting indices value range is -1 to 1. The correlation value of the EVI indices with the spectroradiometer field measurement indices is higher than the NDVI indices. The correlation value is 0.73 which indicates that the relationship between these two parameters is 73%. Mangrove density classification is classified into 6 object classes, namely no vegetation, low, medium, rather high, high and very high. The overall accuracy value of the mapping results is 87.50%, this shows a fairly good accuracy at the mangrove mapping scale.