In this opinion piece on SpaceNews by Dana Goward and Martin Faga, several topics are discussed including America’s GPS vulnerability, the situation in Taiwan, and China’s terrestrial PNT network.

If a conflict between China and Taiwan were to arise, the United States would likely intervene. In response, China would attempt to degrade or disrupt the US’s GPS constellation which provides pointing, navigation, and timing (PNT) to the US military as well as numerous commercial industries. Denying the United States the ability to use GPS would come with serious consequences. As such, the consequences may be so severe to even dissuade the US from joining the conflict – leaving Taiwan to fall.

Given the nature of the US’s GPS constellation being in space, it is vulnerable to China’s arsenal of conventional anti-satellite weapons, such as missiles. If the US were to expand the GPS constellation by adding more spacecraft, the effect of an attack on a single GPS spacecraft would have a lower effect on the GPS PNT service. However, China could just use more missiles to blanket the entire constellation – the avenue of attack is the same, as is the original problem. Instead, the United States needs an alternative to the GPS constellation for PNT.

The SpaceNews article surfaces an idea which many others miss – China has a terrestrial PNT system as well as a space-based PNT satellite constellation. China’s terrestrial PNT service is able to cover the land area of China as well as up to 1,000 miles offshore, which easily covers Taiwan and the surrounding area up to Japan and South Korea. The two PNT systems have the ability to interoperate or as two solo systems. Therefore, even if China’s space-based PNT system were to be countered in the conflict, it would still have the terrestrial system to provide service. China can disrupt the US’s PNT capabilities, while the US is likely unable to disrupt China’s PNT capabilities without placing munitions on land or through cyber-attacks. The article states “eliminating this strategic imbalance must be a key part of deterring a Chinese invasion of Taiwan.”

The United States will need to place more effort into achieving a terrestrial (or other) PNT service that can operate while the GPS constellation is degraded, disrupted, or destroyed.

Information provided by: https://spacenews.com/defending-taiwan-by-countering-chinas-biggest-threat/