LRF1831C 1535nm Eye-Safe UAV Laser Rangefinder Module for Aerial Mapping, Target Tracking and Terrain Measurement

TECHNICAL SPECIFICATIONS

OUTLINE DIMENSION(mm)

113×76×90mm

PIN INTERFACE

Selectable between TTL (Molex 51021-0500) / RS-422 (J30J)

1 Electrical connector model: Molex51021-0500. The detailed definition of the electrical interface is as follows:

Table 1 Interface definition

2. Electrical connector model: J30J; The corresponding plug and cable shall be provided by Party B. The detailed definition of the electrical interface is shown in the following table:

Interface Definition

Product Description

LRF1831C 1535nm Eye-Safe UAV Laser Rangefinder Module for Aerial Mapping, Target Tracking and Terrain Measurement

The LRF1831C is a high-performance 1535nm eye-safe laser rangefinder module specially designed for UAV applications. It combines long-range capability, high accuracy and low power consumption, making it particularly suitable for aerial mapping, target tracking, terrain profiling and reconnaissance missions in compact UAV gimbals and EO/IR payloads.

Operating at a wavelength of 1535nm±0.005µm, Class I eye-safe, the LRF1831C uses a divergence angle of ≤1.3mrad, laser energy ≥350µJ and a Φ60mm receiver lens to balance long-range performance with a footprint and beam pattern that work well from altitude. Under line-of-sight conditions with visibility ≥15km and humidity ≤80% at 30°C, it achieves ≥6500m on Target 1 (5m×15m) and ≥12000m on a diffuse reflectance ≥30% target (20m×20m). The minimum range is ≤50m, making it feasible for both mid- and long-range UAV tasks.

The module supports both single-shot and continuous ranging, with a configurable ranging frequency from 0.5Hz to 10Hz. It offers three-target ranging with near/far target indication, so UAV mission software can distinguish front and back targets in cluttered scenes such as buildings, tree lines and terrain ridges. Range accuracy is ±2m, resolution ≤0.1m, precision rate ≥98% and false alarm rate ≤1%, meeting typical requirements for aerial survey, navigation support and ISR (intelligence, surveillance and reconnaissance) applications.

Functionally, the LRF1831C provides:

• Single and continuous ranging modes

• Three-target ranging with near/far target indication

• A built-in self-test function that reports APD temperature, high-voltage value, internal voltages and blind-zone distance

• A standby wake-up function to reduce power consumption when the UAV payload is idle

Electrically, the module operates from a DC 12V supply. Standby power consumption is ≤1.2W, average power ≤2W and peak power ≤3W, which is attractive for battery-powered UAV platforms and lightweight EO/IR turrets. The LRF1831C is available in a pin-in-lead J30J package with an RS-422 serial interface, and it also supports a TTL (3.3V) interface via a Molex 51021-0500 5-pin connector (RX, TX, CTRL, +12V, GND).

The communication format is selectable between TTL and RS422 at 115200bps, 8 data bits, one start bit, one stop bit and no parity, using a simple master–slave protocol. Command frames start with 0x55 followed by a command word, length, parameter bytes and an XOR checksum. Commands include standby (continuous ranging stop), single ranging, continuous ranging with an adjustable period in milliseconds, self-test, distance selection and blind-zone setting, cumulative shot-count query, APD power on/off and serial-number query. Range responses carry up to three distances (0.1m resolution) from near to far plus a flag byte that reports main-wave and return-wave presence, laser status, timeout, APD status and whether fore and aft targets exist, giving UAV integrators a detailed status picture for robust algorithm design.

Mechanically, the LRF1831C measures 113×76×90mm and weighs ≤410g, providing a solid yet still UAV-compatible form factor for medium-size gimbals and airborne pods. It is rated for an operating temperature range of −40 to +70°C, storage from −55 to +75°C and meets MIL-STD-810G impact and vibration test standards, ensuring reliable performance under flight vibration, take-off and landing shocks and harsh environmental conditions.

For systems that require a protective optical window on the UAV turret or pod, an anti-reflective (AR) coating optimised for 1525–1545nm with transmittance ≥99% is recommended. After additional hydrophobic or hard coatings and mechanical integration, overall transmittance should remain ≥97%. The effective aperture and outer diameter of the window, its thickness (typically 2–4mm), the alignment of the emission axis within 2–4° of the window normal and a minimal air gap all follow the usual geometry guidelines to control absorption and back-reflection.

With its UAV-focused design, 6.5km / 12km performance, Class I eye safety, three-target ranging, low power and flexible TTL/RS422 interface, the LRF1831C is an excellent choice for aerial mapping payloads, UAV target tracking and cueing systems, terrain-following and obstacle-measurement sensors, airborne reconnaissance pods and other UAV EO/IR platforms that need reliable mid-to-long-range distance data in a compact core.