UPDATE - The ADV Ocean Shield is on its way to Fremantle where it will be fitted with the U.S. Navys Towed Pinger Locator 25 System, which has already arrived in Perth.
It appears it will take a couple of days to fit up the Ocean Shield with the towed Pinger Locator.
Then there will be another couple of days travel to the search area, as the Ocean Shield only does 16kts maximum.
On its way West from Sydney, it was only making 13.2kts headway through the Gt Australian Bight, running against fairly constant prevailing Westerly winds.
It really is a race against time, before the FDR battery fails.
ADV Ocean Shield - Wikipedia, the free encyclopedia
If the FDR is found, the acoustic signal of the FDR pinger is transmitted up the Pinger Locator cable and can be output to either an oscilloscope or a signal processing computer (I didn't know oscilloscopes were still in use, in the U.S. Navy!).
The operator monitors the greatest signal strength and records the navigation coordinates, and then the ship repeats the procedure on multiple track lines until the final position is triangulated.
The Pinger Locator has a capability of 20,000' (over 6,000M). The sea bed in the region of the search zone is up to 4,500M deep.
What would be of concern, is the width of coverage of the Pinger Locators. If the width of coverage is only around the maximum operational depth quoted, that means a lot of track lines to be done!
Those "bright, reflective, possible debris objects" in the sat pics could also be remnant ice floes, too!
Another cold front with increased rain, cloud and wind is going to pass through the search zone this (Thurs 27th) afternoon, and will hamper search efforts until the weather clears again, possibly Friday afternoon.