How can I retrieve SpatialRef from a modeltype geographic for a geotiff image?

Hi all, I have a Radarsat2 image in geotiff format. when I use the function geotiffinfo, I get:

Filename:

if true
  % code
end 'C:\Users\Utente\Documents\MATLAB\i...'
        FileModDate: '28-apr-2015 21:12:24'
           FileSize: 93821120
             Format: 'tif'
      FormatVersion: []
             Height: 5776
              Width: 4040
           BitDepth: 16
          ColorType: 'grayscale'
          ModelType: 'ModelTypeGeographic'
                PCS: ''
         Projection: ''
             MapSys: ''
               Zone: []
       CTProjection: ''
           ProjParm: []
         ProjParmId: ''
                GCS: 'WGS 84'
              Datum: 'World Geodetic System 1984'
          Ellipsoid: 'WGS 84'
          SemiMajor: 6378137
          SemiMinor: 6.3568e+06
                 PM: 'Greenwich'
  PMLongToGreenwich: 0
          UOMLength: ''
  UOMLengthInMeters: []
           UOMAngle: 'degree'
  UOMAngleInDegrees: 1
          TiePoints: [1x1 struct]
         PixelScale: []
         SpatialRef: []
          RefMatrix: []
        BoundingBox: []
       CornerCoords: [1x1 struct]
       GeoTIFFCodes: [1x1 struct]
        GeoTIFFTags: [1x1 struct]
   ImageDescription: '{
bandList = 
[
  1;
  2;
...'

So, you can see the TypeModel is geographic but there aren't fields for SpatialRef and RefMatrix. How can I get them from this image. I want to precise that image is georeferenced and in fact in field TiePoints there are two other field

if true
  % code
ImagePoints: [1x1 struct]
WorldPoints: [1x1 struct]

where ImagePoints contains

if true
  % code
Row: [240x1 double]
Col: [240x1 double]

and they represent point of my image, while WorldPoints contains

 X: [240x1 double]
 Y: [240x1 double]

and they represent respectively the Lat and Lon for the pixels above mentioned. Thank you in advance.

Salvatore