Hi, I'm a graduate student and I'm looking for basic materials for down-scaling TRMM and GPM products for hydrological purposes. Which references or papers do you think are the most fundamental materials?
My English is not very good but I will give an idea, I could make a grid of the area and in it represent the measurement stations, each one of them will be at a certain distance and I could find its center of mass. From this, variability could be estimated with a directional or simple variogram. You could also use matlab instructions or R libraries to find sections by K-means and measure the variability of the data.
There are many papers and each has its own merit. There are several good ones recently published in the Theoretical and Applied Climatology journal. In these papers you will find how the earth observations are set as the references to compare with the TRMM or GPM. There are also other journals with good papers. Do not limit your search for some specific papers or journals. The more you search the more you would find good papers.
In addition, you can find many good papers about the down-scaling methods. You may refer to the papers of Mikhail Semenov at Dr. https://www.researchgate.net/profile/Mikhail_Semenov . He is leading the LARS-WG as the well known down-scaling tool.