|Points scan in +i direction|
|Points scan in -i direction|
|Points scan in -j direction|
|Points scan in +j direction|
|Adjacent points in i direction are consecutive|
|Adjacent points in j direction are consecutive|
|reserved; set = 0|
i direction is defined as west to east along a parallel of latitude, or left to right along an x axis.
j direction is defined as south to north along a meridian of longitude, or bottom to top along a y axis.