Malaysia's government and the British satellite company Inmarsat released on Tuesday the data used to determine the course of missing Malaysia Airlines Flight MH370
The move was made in response to mounting calls from passengers' relatives for greater transparency.
The data, comprising satellite communications with the plane, occupy 47 pages in a report prepared by Inmarsat. The information includes hourly "handshakes" - network log-on confirmations - after the aircraft disappeared from civilian radar screens on March 8, Reuters reported.
Families of passengers are hoping that opening the data to analysis by a wider range of experts can help verify the plane's last location, nearly three months after the Boeing 777, carrying 239 people including 154 Chinese passengers, vanished en route from Kuala Lumpur to Beijing.
Based on Inmarsat's and other investigators' analyses, the aircraft was believed to have gone down in the Indian Ocean, off western Australia.
Malaysian investigators suspect someone shut off MH370's data links, making the plane impossible to track, but investigators have so far turned up nothing suspicious about the crew or passengers.
An Inmarsat satellite picked up a handful of handshake "pings", indicating the plane continued flying for hours after leaving radar. The data helped narrow the search in the Indian Ocean.
The dense technical data released on Tuesday details satellite communications from before MH370's takeoff on a Saturday morning at 12:41 am local time (1641 GMT) to a final, "partial handshake" transmitted by the plane at 8:19 am (0019 GMT). The data include a final transmission from the plane eight seconds later, after which there was no further response.
Greg Waldron, managing editor of the Singapore-based aviation publication group Flightglobal, said the satellite data were consistent with what Inmarsat had previously revealed.
"Basically it shows the timings of the handshakes of the plane with the satellite over the Indian Ocean," AFP reported him as saying.
"But I would not dare to guess if they are searching in the right place. The fact that they are using this type of data shows how desperate the search for the plane is."
On Tuesday, the Chinese relatives in Beijing said they had not received any of the data directly from Malaysian authorities.
Wang Guanyi, a representative of the families, said he received a copy of the data from a Malaysian family member at about 2 pm.
"What we ask for is not only the data but also the complete report that led to the Malaysian authorities' conclusion that the aircraft ended in the southern Indian Ocean. We need to know the process of the calculations so we can turn to some experts and ask them to analyze it," Wang said.
Wang said the latest report was too vague, with only two pages explaining the data.
"We don't know what all these figures mean; we have given them to some experts we know for help," he said.
Calculations based on the pings and the plane's possible speeds showed that it likely went down in the remote ocean seven to eight hours after its normal communications were apparently cut, Reuters reported. The time of the last satellite contact was consistent with the plane's fuel capacity.
The search in an area about 1,550 km northwest of Perth was further narrowed on the basis of acoustic signals believed to have come from the aircraft's "black box" data recorders before their batteries ran out.
The most extensive search in aviation history failed to turn up any trace of the plane. Officials have said that it could take a year to search the 60,000 sq km area where it is presumed to have come down.
Hou Liqiang contributed to the story