Radar Classes: SRR, MRR, LRR

SRR, MRR, and LRR describe approximate application and range categories for automotive radar; they do not define uniformly standardized distance limits. They are subject to EMC and radio compliance requirements under regulations such as ECE-R-10 and the Radio Equipment Directive.

Scope and Application

Automotive radar systems are deployed in passenger cars and commercial vehicles to enhance driving safety and situational awareness. Typical applications include:

• SRR (Short-Range Radar): Blind-spot monitoring, parking assistance, and stop-and-go functions

• MRR (Mid-Range Radar): Lane-change assistance and cross-traffic alerts

• LRR (Long-Range Radar): Adaptive cruise control and highway-assistance functions

Actual detection range depends on sensor design, installation, target, and operating environment.

Radar sensors are often integrated into bumpers or behind emblems and require precise calibration and testing to meet regulatory and performance standards.

For detailed specifications and test requirements, see the Automotive Radar – Technology & Compliance Guide.

Key Technical Requirements

Radar sensors must comply with both regulatory and functional requirements:

• Frequency allocations: Automotive radar commonly uses ranges around 24 GHz and 76–81 GHz. Availability, permitted sub-bands, and technical limits vary by jurisdiction

• Transmitter power: Must remain within defined limits (e.g., per ETSI EN 301 091, FCC Part 95)

• EMC and RF testing: Required under frameworks such as ECE-R-10, RED (EU), or FCC/ISED (US/Canada)

• Performance parameters: Include range accuracy, angular resolution, multi-target detection, and noise immunity

Pre-compliance testing, validation in real-world scenarios, and emission-power calibration support product development and preparation for the applicable approval tests.

Certification and Compliance

Depending on the target market, the following frameworks may apply:

• Europe: ECE type approval under ECE-R-10, combined with RED compliance

• North America: FCC/ISED radio approval and conformity with local EMC standards

• Other markets: Country-specific homologation (e.g., MIC Japan)

Whether testing by an accredited laboratory is required depends on the target market and approval procedure. Additional development and validation testing supports assessment of reliability under electromagnetic and environmental stress conditions.

Lifecycle Relevance

Radar classes play a key role throughout the automotive development lifecycle:

• Early-stage performance verification (e.g., noise immunity, range validation)

• EMC and RF type approval testing before market entry

• Reassessment after hardware updates or functional extensions