%set up the model (global variables)

global  time
global  amplitude
global  line_width
global  depth
global  sources
global  receivers
global  spacing
global  velocity1
global  layer

clear all;

time = 0:2:600;  % time sampling
amplitude = 50;

sources = 0:500:1000;
receivers = 0:25:1000;
depth = 500;
velocity1 = 2;

line_width = receivers(length(receivers));
spacing = line_width/length(receivers);

% draw a layer
layer = picklayer(line_width,depth);