##### ASW comparison with in situ observations #####

The evaluation is performed for the ASW product of the satellite sensors. 
These satellite data are compared to GTS (Global Telecommunication System) in situ buoy data.
GTS in situ observations are downloaded from the Japan Meteorological Agency.
We calculate bias and RMSE (Root Mean Square Error) after making in situ to satellite match-up data.

How to make match-up data is 

To perform ASW comparison, buoy observations are collocated with the 10 satellite observations within 30 kilometers and 2 hours.

To calculate the bias and RMSE, satellite observations are collocated under this condition. 
a. At least 2 footprints are available with good quality.
b. Maximum difference among 10 AMSR2 footprints is less than 3 m/s.

If these conditions are satisfied, we calculate the bias and RMSE 
between buoy and average of the nearest ten available satellite.


How to calculate bias is 
    diff(i)=satellite(i)-insitu(i)
    bias=(diff(1)+.......diff(N-1)+diff(N))/N
How to calculate RMSE is  
    RMSE*RMSE=((diff(1)-bias)*(diff(1)-bias)+.......+(diff(N)-bias)*(diff(N)-bias))/(N-1)

The left panels let you choose which sensor and product to check. 
At last if you click update button, bias and RMSE are plotted.