There are inconsistent descriptions in the IOM3.1 concerning
the allowed area of ISOPHOT sparse map (P17,18,19, and P37,38,39):
p.34 ``...within an area of 3 degrees in diameter, ......''
p.44 ``...within a field of 1.5 degrees diameter. ...''
p.78 ``...confined to 1.5 x 1.5 square degrees. ...''
The correct description is that the allowed area of ISOPHOT sparse map must
lie within a circular area of 3 degrees in diameter with the first selected
pointing determining the centre.
Similarly, all pointings for concatenated observations have to be confined
within a circle of 1.5 degrees radius.