Converting Aster L1T data radiance to surface reflectance in Google Earth Engine

Question

I'm working with Aster data in GEE and it's necessary to convert radiance in surface Reflectance values. I've tried to convert DN to TOA values, like this. It works. But I'm a little confused about convert TOA values to BOA values. I know that it's necessary to apply the atmospheric correction. I've looked around for the best model for ASTER data in GEE, but I didn't find a good solution yet

var aster1 = ee.Image('ASTER/AST_L1T_003/20000507134140');
var gainRED = aster1.get('GAIN_COEFFICIENT_B02');
print(gainRED);
var rad_RED = ee.Image('ASTER/AST_L1T_003/20000507134140')
                  .select('B02')
                  .subtract(1)
                  .multiply(0.708);
print(rad_RED);
Map.addLayer(rad_RED);

Answer 1

First, if you want to atmospheric correction, you need a Atmospheric radiative transfer, such as MORTRAN,6S. Second, the Model runs in your computer. So if you want to use the GEE, you have to use the Python API. You can refer this. https://github.com/samsammurphy/gee-atmcorr-S2/blob/master/jupyer_notebooks/sentinel2_atmospheric_correction.ipynb