The Chinese Navy has been using commercial navigational radars on many of its war ships, including many of its most modern vessels. This makes them rather easy targets for US electronic intelligence. Whether the Chinese are using this equipment out of poverty, or as a way to avoid wasting money on custom superior systems, is undetermined. The frugal explanation is the most likely, as the Chinese have a habit for using whatever will work, as long as it's cheap. The Chinese probably believe that it would be futile to try and develop, or buy, a special military navigation radar that could avoid detection by the Americans. They are probably right.