Inmarsat Paper
@megan - 8 Oct 2014 15:58 -- Thanks for the link to the Inmarsat paper! A very detailed explanation of their processing, and the evolution.
Some observations made in the paper:
"While the validation demonstrates the general accuracy of the BFO technique, it is important to note that agreement is only achieved with ±7 Hz accuracy during this flight, and to assume better accuracy for the measurements taken on MH370 would be unrealistic."
"Combining the sensitivity data with the measurement accuracy of ±7 Hz indicates that inaccuracy in each individual BFO measurement would correspond to ±28° heading uncertainty and ±9° of latitude uncertainty."
Which helps to explain the size of the potential solution area.
At or above the tropopause in a standard atmosphere, the speed of sound is about 1062 km/hr. The speeds shown in their Table 9 range from about 0.75 M to 0.82 M for a standard day above the tropopause, a reasonable range for max distance cruise. Granted the table shows groundspeed, not airspeed, but the headwind or tailwind component would probably be small on a southerly track.
The latest charts from ATSB show that they have done the bathymetric survey on a fairly narrow swath about the 7th arc, and plan to search initially along that narrow swath. The bathymetric survey covered a broader cross-arc distance for regions more to the NE.
Will they need to conduct additional bathymetric surveys prior to expanding the search area on either side of the arc?