緯距 is read as いきょ (ikyo) and means latitude.
いきょ
ikyo
いど
latitude (nav.)
い
weft
いどへんか
latitude variation
いどかんそくじょ
latitude observatory
いしょ
book of omens appended to Confucian Chinese classics
いせん
parallel
こうきょ
elevation (above sea level)
けいきょ
departure (surveying, etc.)
けいい
longitude and latitude
きょり
difference (e.g. in opinion)
きんきょり
short distance
えんきょり
long distance