Fix retrograd movements and earth rotation

utils/plot-satellites.gnuplot

@@ -1,20 +1,31 @@
-set datafile separator comma
+set datafile separator ",:" 
 set key autotitle columnheader
-set terminal gif animate
+set terminal gif animate size 2000,2000
 set output 'output.gif'
 
 unset xtics
 unset ytics
 unset ztics
 unset border
+set xrange [-8e6:8e6]
+set yrange [-8e6:8e6]
+set zrange [-8e6:8e6]
+set parametric
+set isosamples 100,100 
 unset key
 set hidden3d
-set view equal xyz
 
 # number of nodes per time slot
-n=1200
+EARTH=6.370e6
+sats=ARG1
+ground=ARG2
+numsats=ARG3
+numsamples=ARG4
 
-do for [j=0:100] {
+do for [j=0:numsamples] {
 	set title 'time '.j
-	splot 'leo-circular-orbit-tracing-example.csv' using 3:4:5:2 every ::(j*n)::((j+1)*n)
+	splot [-pi:pi][-pi/2:pi/2] EARTH*cos(u)*cos(v), EARTH*sin(u)*cos(v), EARTH*sin(v), \
+	      ground using 1:2:3 lt rgb "green", \
+	      sats using 3:4:5:2 every ::(j*numsats)::((j+1)*numsats) lt rgb "blue"
+	      
 }