The Malaysian government has released 45 pages of raw satellite data it used to determine that the missing airliner crashed into the southern Indian Ocean.
Authorities were responding to demands for greater transparency by relatives of some of the 239 people on board Malaysia Airlines flight MH370.
But at least one independent expert said his initial impression was that the communication logs did not include key assumptions, algorithms and metadata needed to validate the investigation team's conclusions that the plane flew south after dropping off radar screens 90 minutes into the flight.
Michael Exner, a satellite engineer who has been researching the calculations, said: "It's a whole lot of stuff that is not very important to know. There are probably two or three pages of important stuff, the rest is just noise. It doesn't add any value to our understanding."
Almost three months since it went missing en route to Beijing from Kuala Lumpur, no trace of the jet has been found.
Several family members have been highly critical of the Malaysian government's response, accusing them of failing to release timely information or even concealing it. The government, which in the early days did release contradictory information about the plane's movements, insists it is being transparent in what has been an unprecedented situation.
An international investigation team led by Malaysia has concluded that the jet flew south after it was last spotted on Malaysian military radar and ended up in the southern Indian Ocean off western Australia. This conclusion is based on complex calculations derived largely from hourly transmissions between the plane and a communications satellite.
An unmanned US Navy sub that has been scouring a 155 square mile patch of seabed since April is scheduled to finish its mission tomorrow. The Bluefin 21 has been searching area where sounds consistent with aircraft black boxes were detected last month.
The next search phase will be conducted over a much bigger area - about 23,000 square miles - and will involve mapping of the seabed. The area's depths and topography are largely unknown.
Officials are looking to hire powerful sonar equipment that can search for wreckage in deeper water than the Bluefin.
Angus Houston, who is heading up the search, said in early May that it would take a couple months before any new equipment would be ready to be deployed.
The technical data released today consisted of data communication logs from the satellite system operated by the UK's Inmarsat company. The plane sent hourly transmissions to a satellite. The signals were never meant to track an aircraft's path, but investigators had nothing else to go on because the plane's other communication systems had been disabled.
Investigators determined the plane's direction by measuring the frequency of the signals sent to the satellite. By considering aircraft performance, the satellite's fixed location and other known factors, they determined the plane's final location was to the south of the satellite.
In an interview with CNN earlier this week, Inmarsat's chief engineer Mark Dickinson said he was confident in the data,
"This data has been checked, not just by Inmarsat but by many parties, who have done the same work, with the same numbers, to make sure we all got it right, checked it with other flights in the air at the same, checked it against previous flights in this aircraft. At the moment there is no reason to doubt what the data says."
Sarah Bajc, whose husband was on the flight, does not believe that the plane few south and had been critical of the Malaysian government. She has been at the forefront of a campaign to press the government for more transparency.
She said that "a half dozen very qualified people were looking" at the information and she hoped to have their take soon.
But along with Mr Exner, she was also critical of the way it was released. The government put it in a PDF file not in its original data form, making working with it far more time-consuming.
"A little tweak to make people work harder needlessly," she wrote in an email.
In a posting on its Facebook page, a group representing some of the families said: "Finally, after almost three months, the Inmarsat raw data is released to the public. Hope this is the original raw data and can be used to potentially 'think out of the box' to get an alternative positive outcome."
In China, home of about two-thirds of the passengers, several relatives said they were not informed by Malaysia Airlines ahead of the release. Steve Wang, whose mother was on the plane, said he was disappointed that the release did not contain an account of exactly what investigators did to conclude the plane had taken the southern route.
"We are not experts and we cannot analyse the raw data, but we need to see the deduction process and judge by ourselves if every step was solid," he said.
"We still need to know where the plane is and what is the truth. We know the likelihood that our beloved ones have survived is slim, but it is not zero."
Duncan Steel, a British scientist and astronomer, said some of the data "may" explain the belief that the aircraft went south rather than north, but further confirmation would take a day or so. But he too was disappointed. "One can see no conceivable reason that the information could not have been released nine or 10 weeks ago. Even now, there are many, many lines of irrelevant information," he said in an email.
Meanwhile, an Australian government report said an analysis of the final brief data exchange, or "ping", between the aircraft and a satellite suggested the plane crashed into the sea because it ran out of fuel.
In a report on its website titled "Considerations on defining the search area", the Australian Transport Safety Bureau said the message was a "logon request from the aircraft that was consistent with satellite communication equipment on the aircraft powering up following a power interruption".
It said the interruption might have been caused by fuel exhaustion.