how to create and save a georeferenced image in .tif format?

Hi! I have 3 arrays 318x2000: the first one contains the pixel values of a grayscale image I and the others the lat and lon values of each pixel. I have to save a georeferenced image in a .tif format but I don't know how to save the position. Shoul I use geotiffwrite? To visualize the image I have written

Z=zeros(num_ping,2*Nbins);
figure(19)
surf(lon_SSS,lat_SSS,Z,I,'EdgeColor','none')
colormap gray

and it works. If I use geoshow the gray levels are brighter. Thank you