Nadizha,

1.Provide in the IKIODB\ATYYMM\ the orbital files as follows:
atyymm.elm, atyymm.ymd, atyymm.str. 

2.Provide in this directory file TK.TIN, wjhoch contains the time-interval.

See as an example, IKIODB\AT9903\T1.TIN

3. Run in the IKIBAT\ the following:

IKIBAT A T YYMM MOD1I3 TK STEP SE

Ex:

IKIBAT A T 9903 MOD1I3 T1 3600 SE

See the results in the IKIODB\AT9903\AT9903T1.SE

I wish you successes.
Victoria