------------------------------------------------------------------------------
    |                                                                            | 
    |                                                TROP12                      | 
    |                                                                            | 
    |                                                                            | 
    |                                                                            | 
    |                  i=1   ------------------- i=361                           |
    |                  j=505 |                 | j=505                           |
    |                        |                 |                                 |
    |                        |     PERU12      |                                 |
    |                        |                 |                                 |
    |                        |    (361x505)    |                                 |
    |                        | 46 /75 niveaux  |                                 |
    |                  i=1   |                 | i=361                           |
    |                  j=1   ------------------- j=1                             |
    |                        .                 .                                 |
    |                        .                 .                                 |
    |                        .                 .                                 |
    |                        .                 .                                 |
    |                        .                 .                                 |
    |                        .                 .                                 |
    -------------------------.-----------------.----------------------------------
                           i=2881            i=3241
                             .                 .
                            100W              70W