The VAT140 appears to be a type of ADS-B (Automatic Dependent Surveillance-Broadcast) transponder system used in vehicles, likely for ground vehicle tracking applications. 
Key Features of VAT140 and Similar Vehicle ADS-B Transponders:
- ADS-B Technology: Uses the same 1090MHz frequency band as aircraft transponders to broadcast position data.
 
- Vehicle Applications: Typically used for:
 
- Airport ground vehicle tracking
 
- Construction vehicle monitoring at airfields
 
- Special vehicle tracking in controlled areas
 
Typical Capabilities:
- GPS-derived position reporting
 
- Speed and heading transmission
 
- Unique vehicle identification
 
- May include additional data like vehicle status
 
Safety Benefits:
- Improves situational awareness for air traffic controllers
 
- Helps prevent runway incursions
 
- Enhances overall airport surface safety