


                                  - 1 -



       COMMAND

       bbbboooorrrrddddeeeerrrr ---- ssssyyyynnnntttthhhheeeessssiiiizzzzeeee eeeelllllllliiiippppttttiiiiccccaaaallll oooorrrr rrrreeeeccccttttaaaannnngggguuuullllaaaarrrr bbbboooorrrrddddeeeerrrriiiinnnngggg rrrriiiimmmm

       USAGE

       bbbboooorrrrddddeeeerrrr [----ccccrrrr] _z__m_i_n _z__m_a_x _w_i_d_t_h [_y__a_s_p_e_c_t]

       ----cccc        Circular (elliptical) bbbboooorrrrddddeeeerrrr, the default.

       ----rrrr        Rectangular border.

       _z__m_i_n     Height of lower inner edge in microns.

       _z__m_a_x     Rim height in microns.

       _w_i_d_t_h     Rim width in microns.

       _y__a_s_p_e_c_t  Ratio of latitudinal extent to longitudinal
                 extent, expressed as a percentage.  The default is
                 100.

       DESCRIPTION

       The bbbboooorrrrddddeeeerrrr command is used to create a user-defined
       bordering rim around the periphery of selected regions of
       cartesian images.  The command will enable you to define
       either elliptical borders (includes circular case) or
       rectangular bbbboooorrrrddddeeeerrrrssss having interesting or useful
       characteristics.

       The outer dimensions of the border is controlled by the
       latitude/longitude range window.  For an elliptical border,
       the direction of the the long axis is determined by aspect
       ratio and the overall length equals the range limits in that
       direction.

       As an example of an elliptical border specification, let's
       assume that you want to enclose your subject within a bbbboooorrrrddddeeeerrrr
       that is say fifteen percent wider than it is high and that
       its overall width is to be such that it extends from
       longitude 50 to longitude 462.  Further assume you wish the
       lower inner lip elevation to be 10000 microns, the top of
       rim elevation to be 35000 microns and the rim width to be
       12000 microns.

       The sequence of commands

       llllggggrrrr 55550000 444466662222













                                  - 2 -



       bbbboooorrrrddddeeeerrrr ----cccc 11110000000000000000 33335555000000000000 11112222000000000000 88886666....99996666

       yields the desired result provided only that the current
       latitude range is at least 87 percent of one half the
       longitude range in extent.  If the latter restriction is not
       met, the latitude range will dictate the long axis
       dimension.

       The interdependence of latitude range, longitude range and
       aspect is strong and it is fairly easy to generate
       combinations that do not do what you might have in mind.
       With a bit of familiarity you will find that this command
       and its argument structure affords considerable flexibility
       in controlling placement, orientation and eccentricity of
       borders.

       The bbbboooorrrrddddeeeerrrr command is frequently used to control the
       elevation to which the ffffiiiillllllll command extrapolates when
       filling void regions external to the terminal data defining
       the features of subjects which have been digitized linearly.
       Use of this command is particularly helpful in controlling
       the background surrounding the subject of a relief developed
       from image data.  This measure of control is made possible
       by the ability to specify a constant elevation for the lower
       edge on the inner surface of the bordering rim.


































