help finding a manual

my dad gave me this GPS type device out of his car. all i can gather is that it is some kind of cell tracking device. im trying to locate an owners manual for it. can anyone help me out? the part number appears to be "NSA1800". i know what GPS is but what the heck is "AMPS" going into the antenna? is there anything cool i can do with this module, as far as hacks or mods? it seems interesting, thanks in advance!

is it a cell phone controller? the company is here http://www.niigata-s.co.jp/ maybe using google translater you might get some useful info all i came up with was cell phone roaming
lg

This may be helpful. You can often get technical information from the FCC website on items that have an FCC ID. In this case, go here:
https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm

in the box entitled "Grantee Code" type in NTR, then scroll down and select "Start Search".

You will see information about three FCC ID entries. In the third row, under Display Exhibits, select Detail. From the list that comes up, go to the bottom and select Manual Rev 2.