function [a_rottgers, a_varying, a_flat] = ac_correct_scatter(wl, a, c)
b = c - a;

% Get a, b and c at 715 and/or 730 nm
n = size(wl,2);
for i = size(a,1):-1:1
  a_730(i,1:n) = interp1(wl, a(i,:), 730, 'linear', 'extrap');
  b_730(i,1:n) = interp1(wl, b(i,:), 730, 'linear', 'extrap');
  a_715(i,1:n) = interp1(wl, a(i,:), 715, 'linear', 'extrap');
  c_715(i,1:n) = interp1(wl, c(i,:), 715, 'linear', 'extrap');
end;
% spectrally flat correction
a_flat = a - a_730;

% spectrally varying scattering correction
a_varying = a - b .* a_730 ./ b_730;

% Rottgers et al., 2013
a_rottgers = a - a_715 .* (1/0.56 .* c - a)./(1/0.56 .* c_715 - a_715);

end