In-Season Mapping of Irrigated Crops Using Landsat 8 and Sentinel-1 Time Series

Remote Sensing

Frédéric Baup¹  Florian Helen²  Claire Marais-Sicre³  Valérie Demarez⁴ 

[1] Space, 31 rue des Cosmonautes, 31400 Toulouse, France;UMR 5126, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France;;Airbus-Defense &Centre d’Etudes Spatiales de la Biosphère;

关键词: irrigated crops;    seasonal crop mapping;    satellite image time series;    Sentinel-2;    Landsat-8;    Random Forest;   

DOI  :  10.3390/rs11020118

来源: DOAJ

【 摘 要 】

Numerous studies have reported the use of multi-spectral and multi-temporal remote sensing images to map irrigated crops. Such maps are useful for water management. The recent availability of optical and radar image time series such as the Sentinel data offers new opportunities to map land cover with high spatial and temporal resolutions. Early identification of irrigated crops is of major importance for irrigation scheduling, but the cloud coverage might significantly reduce the number of available optical images, making crop identification difficult. SAR image time series such as those provided by Sentinel-1 offer the possibility of improving early crop mapping. This paper studies the impact of the Sentinel-1 images when used jointly with optical imagery (Landsat8) and a digital elevation model of the Shuttle Radar Topography Mission (SRTM). The study site is located in a temperate zone (southwest France) with irrigated maize crops. The classifier used is the Random Forest. The combined use of the different data (radar, optical, and SRTM) improves the early classifications of the irrigated crops (k = 0.89) compared to classifications obtained using each type of data separately (k = 0.84). The use of the DEM is significant for the early stages but becomes useless once crops have reached their full development. In conclusion, compared to a “full optical” approach, the “combined” method is more robust over time as radar images permit cloudy conditions to be overcome.

【 授权许可】

Unknown