Satellite Vessel Tracking Helps IMF Build Faster and Smarter Trade Estimates

The IMF has developed a satellite-based system called PortWatch that uses ship-tracking data to estimate country-level trade flows within seven working days, offering policymakers faster insights into global trade trends. The study found the system works especially well for large economies like the U.S., Japan, and Brazil, though smaller economies remain harder to track accurately.

The International Monetary Fund (IMF) has unveiled a new system that uses satellite-based ship-tracking data to estimate global trade flows in near-real time, offering policymakers a faster way to understand changes in the world economy. The research, developed by the IMF's Strategy, Policy and Review Department and Statistics Department along with international trade databases and PortWatch, aims to solve a major problem in economic policymaking: official trade statistics are often released weeks or even months late.

Using data collected from ships moving across the world's oceans, the IMF says it can now estimate monthly imports and exports within seven working days after the end of a month. The project comes at a time when governments are facing growing trade tensions, supply chain disruptions, and rapid shifts in global commerce.

How Ships and Satellites Reveal Trade Activity

The system relies on Automatic Identification System (AIS) signals transmitted by ships. These signals show a vessel's location, movement, and draught — the depth at which a ship sits in the water. By studying changes in draught, researchers can estimate whether cargo is being loaded or unloaded and how much trade is moving through ports.

The IMF's PortWatch platform groups maritime trade into three main categories: container cargo, dry bulk shipments such as grains and minerals, and liquid bulk cargo, including oil and gas. Researchers then combine shipping movements with international trade prices and commodity data to estimate the value and volume of trade.

According to the paper, maritime transport accounts for nearly 80 percent of global trade volume, making shipping data one of the most reliable indicators of economic activity. The IMF says this approach mirrors how official statistical agencies calculate trade figures but delivers results much faster.

Big Economies Show Strong Results

To test the system, researchers applied it to five countries representing different economic structures and income levels: Brazil, Jamaica, Japan, Samoa, and the United States.

The strongest results came from large economies such as Japan, Brazil, and the United States, where PortWatch estimates closely matched official trade statistics. Japan emerged as one of the best-performing examples after researchers used the country's official import and export price indices to improve the accuracy of trade volume estimates.

In Brazil, researchers discovered that offshore oil infrastructure was essential for measuring exports correctly. Since most of Brazil's petroleum exports originate from offshore platforms rather than traditional ports, the IMF added 45 offshore oil and gas facilities into the PortWatch system. Without these additions, Brazil's exports would have been significantly underestimated.

The United States also showed strong results, with PortWatch closely tracking maritime trade trends. Researchers found that shipping data successfully captured broad changes in import and export activity across major U.S. ports.

Small Economies Remain Harder to Measure

While the system worked well for larger economies, the study found that smaller and more volatile economies remain difficult to estimate accurately. Jamaica and Samoa produced weaker results because their trade flows are more affected by irregular shipments and transshipment activity.

Jamaica's Port of Kingston highlighted one major challenge. As a large Caribbean transshipment hub, many goods passing through Kingston are transferred from one vessel to another without entering the domestic economy. AIS data alone cannot easily distinguish between local imports and cargo simply moving through the port. To solve this issue, IMF researchers introduced a "netting adjustment" using official container data to isolate domestic trade activity.

Samoa proved even more difficult because of its small trade volumes and highly irregular shipping patterns. The IMF acknowledged that further refinements will be needed before AIS-based estimates can reliably capture trade flows in small island economies.

A New Tool for a Faster Global Economy

The IMF believes the PortWatch system could become an important complement to official trade statistics rather than a replacement for them. Researchers argue that in today's rapidly changing global economy, governments need faster and more comparable indicators of trade activity.

One example highlighted in the study was the surge in U.S. imports during the first half of 2025 amid rising tariff tensions. Official statistics showed a sharp spike in imports as companies rushed to bring in goods before tariffs increased. However, PortWatch captured a more moderate rise because many of the products driving the surge, such as electronics and pharmaceuticals, were transported by air rather than by sea.

The IMF says this may actually be an advantage. Because maritime shipping reflects slower-moving and less volatile trade flows, PortWatch could provide a clearer picture of underlying economic activity. As global trade becomes increasingly unpredictable, the organization believes satellite-based maritime tracking may become one of the world's most important real-time economic indicators.