Primary Surveillance Radar (PSR) and Secondary Surveillance Radar (SSR) are both types of radar systems used in aviation for aircraft detection and tracking. While both radar and ADS-B are used for aircraft surveillance, they operate on different principles and provide different levels of information. Below is an overview highlighting the distinctions between radar and ADS-B in aviation.
1. The methods of obtaining positions differ between radar and ADS-B. Radar calculates aircraft positions by analyzing the time it takes for radio signals to be transmitted and received. While ADS-B utilizes onboard GPS technology to determine aircraft positions.
2. The requirements for airborne equipment vary between radar and ADS-B systems. Primary surveillance radar does not necessitate any specific airborne equipment. Secondary surveillance radar relies on airborne transponders. Meanwhile, ADS-B requires the installation of airborne GPS receivers and ADS-B transmitters onboard aircraft.
3. There are notable differences in pricing between radar and ADS-B systems. Radar systems tend to be expensive, whereas ADS-B ground stations are relatively affordable. While costs may fluctuate based on brand, radar systems typically exceed the price of ADS-B ground stations by at least tenfold. However, it's essential to note that this price comparison pertains only to the ground components. The pricing of airborne equipment for both radar and ADS-B systems is more complex and cannot be easily summarized.
4. Maintenance requirements vary significantly between radar and ADS-B systems. Radar systems tend to be larger, more complex, and require more intensive maintenance efforts. In contrast, ADS-B ground stations are smaller, simpler, and demand significantly less maintenance work. So ADS-B ground stations are often remotely controlled.
5. Radar and ADS-B serve different applications within aviation surveillance. The primary applications for radar and ADS-B include ground-to-air surveillance and airport surface movement surveillance. However, ADS-B offers additional capabilities, including air-to-air surveillance, beyond the scope of traditional radar systems.
6. Coverage areas differ between radar and ADS-B systems. Initially, radar and ADS-B coverage areas were largely similar. However, with advancements in satellite-based ADS-B technology, ADS-B coverage has expanded globally, encompassing the entire globe. In contrast, radar coverage remains restricted to areas where radar installations are feasible.