India had previously voiced concerns that the ship would be used to spy on its activities, said media reports.
Foreign security analysts quoted by Reuters describe the Yuan Wang 5 as one of China's latest generation space-tracking ships, used to monitor satellite, rocket and intercontinental ballistic missile launches.
Several Indian media reports described it as a dual-use spy ship. Shipping analytics websites call it a research and survey vessel.
One report by Indian news site NDTV said the government in Delhi was concerned about the possibility of the ship's tracking systems attempting to snoop on Indian installations while on its way to Sri Lanka.
Earlier in July, an Indian foreign ministry spokesman said the government was monitoring the ship's planned visit, adding that Delhi would protect its security and economic interests.
According to a Reuters report, India had lodged a verbal protest with the Sri Lankan government against the ship's visit.
Earlier this month, Sri Lanka's foreign ministry had asked China to defer the ship's port call, saying it needed to take further consultations.
China responded, saying it was completely unjustified for certain countries to cite so-called 'security concerns' to pressure Sri Lanka - though it did not name any specific country. Sri Lanka later announced that the vessel would be given permission to dock.
