Development of a neural network for precipitable water vapor retrieval over ocean and land

In this work a method based on neural networks is proposed to retrieve precipitable water vapour over land and over ocean from brightness temperatures measured by the Advanced Microwave Scanning Radiometer - Earth Observing System. In order to train the neural network, water vapour values provided by European Centre for Medium-Range Weather Forecasts, sampled on a regular grid with a spacing of 0.25deg in latitude and longitude, were exploited. The analysis was performed over Italy and the Mediterranean area and, as expected, the water vapour retrieval over a sea background exhibits good accuracy. Over a land background the proposed approach seems to be promising, where a RMS error of about 0.3 cm was achieved.