ATC: Automatic Weather Observing System (AWOS)

Ceilometer1 - for cloud height detection
Is a compact and lightweight instrument for cloud base height and vertical visibility measurements.

Operating environment
- Operating environment: Outdoor use
- Use in wet location: Yes
- Operating temperature: −50 … +60 °C (−58 … +140 °F)
- Operating humidity: 0–100 %RH
- Wind tolerance: Up to 55 m/s (123 mph)

Inputs and outputs
- Operating voltage: 115/230 V AC ±10 %
Current consumption
- Current consumption (maximum): 2.7/1.4 A
- Measurement unit: 0.1/0.1 A

Ceilometer2 - for high-range cloud height detection.
Is designed to measure high‑range cirrus cloud heights without surpassing the low and middle layer clouds, or vertical visibility in harsh conditions.


Measurement range 0–13 km (0–43 000 ft)
Backscatter
profiling range 0–15 km (0–49 200 ft)
Reporting resolution 10 m (30 ft), units selectable
Reporting cycle 6–120 s, or polling
Distance measurement accuracy against a hard target ±5 m (16 ft)

Inputs and outputs
- Operating voltage 115/230 V AC ±10 %
- Current consumption (typical) 2.7/1.4 A
- Overvoltage category II
Interfaces
- Data
• RS‑232
• RS‑485, multidrop, 2‑wire
• DXL421 modem module
• LAN (Ethernet) interface option
- Maintenance RS‑232
Baud rate
- RS‑232/RS‑485 300–115 200 bps
- Modem V.21, V.22 300–1200 bps

Forward Scatter Sensor - combines forward scatter and optical disdrometer technologies. Sets the standard in precipitation identification and quantification, providing best-in-class visibility determination.

Visibility (MOR) measurement
- Reporting range 1 m–100 km (3 ft–62 mi)
- Reporting resolution 1 m (3 ft)
- Reporting uncertainty in operational conditions
±10 % or ±1 m at 1 m–10 km (±3 ft at 3 ft–6.2 mi)
±20 % at 10–100 km (6.2–62 mi)


Transmissometer - enables accurate and reliable single baseline measurement for CATIIIb category airports.

Recommended Baseline Lengths
30 m (98 ft) baseline length (optimal) MOR: 10 … 10 000 m (33 … 32 808 ft)
Transmittance range: < 0.01 % … 100 %
50 m (164 ft) baseline length MOR: 25 … 10 000 m (82 … 32 808 ft)
Transmittance range: < 0.02 % … 100 %
75 m (246 ft) baseline length MOR: 37.5 … 10 000 m (123 … 32 808 ft)
Transmittance range: < 0.02 % … 100 %

Thunderstorm Local Lightning Sensor
Is a local-area lightning detection sensor that can be integrated with
automated surface weather observations.
Measurement performance
Detection range 30 nmi (56 km) radius from sensor
loca
tion
Range resolution Three range groups:
• 0 … 5 nmi (0 … 9 km)
• 5 … 10 nmi (9 … 19 km)
• 10 … 30 nmi (19 … 56 km)
Range resolution uncertainty 0 … 10 nmi (0 … 19 km): less than
3 nmi (5.6 km)
10 … 30 nmi (19 … 56 km): less than
6 nmi (11.1 km)
Bearing resolution One of eight compass octants (N, NE,
E, SE, S, SW, W, NW)
Detection efficiency
Thunderstorm detection 98 % for thunderstorms within
10 nautical miles (12 mi, 19 km) with 3
or more cloud-to-ground discharges
Cloud-to-ground flashes Approximately 70 % for flashes within
10 nautical miles