function [gpmm1800 gpmm3600] = find_wavelength(crc_wavelength)

a = -1.0911e-06;
b = 0.0017424;
c = 13.006;
diff1800 = a*crc_wavelength^2 + b*crc_wavelength + c;
gpmm1800 = diff1800 + crc_wavelength;

m = -0.00036466;
b = -83.76;
diff3600 = m*crc_wavelength + b;
gpmm3600 = diff3600 + crc_wavelength;