Ground Radars used for Aircraft Tracking
Ground-based radars are radar systems installed at airports or air traffic control stations to monitor aircraft. They detect and track aircraft positions, speed, and altitude to ensure safe and efficient air traffic management. These radars help controllers during take-off, landing, en-route flight and in poor weather conditions.
Types of Primary Ground Radars
- Ground-based Primary Radars are used for Air Traffic Control (ATC) surveillance.
- The main types of Primary Ground Radars are:
- Area Surveillance Radar (RSR)
- En-route Surveillance Radar (same as RSR)
- Terminal Surveillance Radar (TSR)
- Aerodrome Surveillance Radar (ASR)
- Precision Approach Radar (PAR)
- Aerodrome Surface Detection Equipment (ADSE)
- Airport Surface Movement Radar (same as ASDE)
Area (En-route) Surveillance Radar (RSR)
- Area Surveillance Radars are long-range surveillance radars.
- They are used by the Area Control Centre (ACC) for monitoring aircraft along air routes.
- Frequency: 600 – 3000 MHz
- Wavelength: 10 – 50 cm
- Pulse Recurrence Frequency (PRF): 250 pulses per second
- Pulse Length: 2 – 4 microseconds
- Antenna Rotation Rate: 5 revolutions per minute (RPM)
- Maximum Range: 200 – 300 NM
Terminal Surveillance Radar (TSR)
- Terminal Surveillance Radars are medium-range surveillance radars.
- They are used to maintain aircraft separation within the Terminal Control Area (TMA).
- Frequency: 600 – 3000 MHz
- Wavelength: 10 – 50 cm
- Pulse Recurrence Frequency (PRF): 500 pulses per second
- Pulse Length: 1.5 – 2 microseconds
- Antenna Rotation Rate: 15 revolutions per minute (RPM)
- Maximum Range: 75 – 100 NM
Aerodrome Surveillance Radar (ASR / SRE)
- Aerodrome Surveillance Radar is also known as Surveillance Radar Equipment (SRE).
- SRE is a short-range radar used by Approach Control.
- It provides vectors to aircraft during approach when required.
- It monitors aircraft until they are established on the ILS Localiser.
- Frequency: 10 GHz
- Wavelength: 10 – 50 cm
- Pulse Recurrence Frequency (PRF): 1000 – 2000 pulses per second
- Pulse Length: 0.5 – 0.8 microseconds
- Antenna Rotation Rate: 30 revolutions per minute (RPM)
- Maximum Range: Approximately 25 NM (20 – 30 NM)
Precision Approach Radar (PAR)
- Precision Approach Radar is a very short-range radar system.
- It provides precision approach guidance mainly at military airfields.
- PAR consists of two radar systems combined to provide:
- Azimuth guidance.
- Elevation guidance.
- It provides continuous “talk down” instructions until touchdown.
- Frequency: 10 GHz
- Wavelength: 10 – 50 cm
- Pulse Recurrence Frequency (PRF): More than 1000 pulses per second
- Pulse Length: 0.5 – 0.8 microseconds
- Antenna Rotation Rate: Sector scanning at approximately 120 scans per minute
- Maximum Range: Less than 25 NM
Airport Surface Detection Equipment (ASDE)
- Airport Surface Movement Radar, Airfield Surface Movement Indicator, and Aerodrome Surface Detection Equipment are systems used for monitoring airport surfaces.
- ASDE provides the position of aircraft and vehicles operating on the ground.
- It uses a very narrow beam width to provide high-resolution ground movement information.
- Frequency: 15 – 17 GHz
- Wavelength: Approximately 2 cm
- Pulse Recurrence Frequency (PRF): More than 10,000 pulses per second
- Pulse Length: 0.03 microseconds (1/300 microseconds)
- Antenna Rotation Rate: 60 revolutions per minute (RPM)
- Maximum Range: Less than 5 NM
Ground Radar Summary
- PRF – Pulse Recurrence Frequency
- PW – Pulse Width
- ARR – Antenna Rotation Rate