Locations of five acoustic receivers (blue) in Cape Cod Bay.

The Cornell Laboratory of Ornithology deployed these autonomous, time-unsynchronized receivers in the summer of 2019 to study right whales.

Extremely reliable 100% confidence interval of location (red) derived from Time-Differences-Of-Arrival (TDOA) of a call (below) recorded on four (circled) of the five receivers.

All phenomena affecting location are accounted for including uncertainties in measured TDOA, echoes, receiver locations, speeds of sound, and clock uncertainty. Location derived with Scientific Innovations software. (US Patents 7,219,032, 7,363,191, 8,010,314, 8,311,773, and 8,639,469). Work performed in collaboration with the Cornell Laboratory of Ornithology and Harvard University.

Acoustical signal at one receiver showing a call from one right-whale.

Twenty 100% confidence intervals of location (red) for 20 calling right whales during a 19.8 min interval on 20 February 2019 in Cape Cod Bay, MA. Locations derived with sequential bound estimation(US Patents 7,219,032, 7,363,191). The time shown at the top of each frame is the elapsed time in minutes since the first whale's call was received. Each receiver's clock is synchronized using the time-differences of arrival of many hundreds of whale calls using US patent 10,915,137. The mathematically-certified lower bound for the number of whales responsible for these sounds is two (US Patent 10,929,506). The location of a receiver is circled if it is used to locate a whale.