LR1000C3 905nm Compact Laser Rangefinder Module for Thermal Imagers, Night Vision Devices and UAV Payloads

Technical Specifications

Notes:

1)The target size is 2.3m × 2.3m with a reflectivity of 90%.

2) The target size is 2.3m × 4.6m with a reflectivity of 90%.

3) The accuracy indicated in the table is the accuracy for the white board.

Functional Description

The system supports single measurement and continuous measurement functions.

3.1 External Circuit Enable
Enables the module for normal operation.

3.2 External Circuit Disable
Disables the external circuit to reduce power consumption.

3.3 Single Measurement
Triggers a single distance measurement to the target. For low-reflectivity targets, the system automatically repeats measurements until stable distance data is obtained. The result is then transmitted via the serial interface in the standard data format.

3.4 Continuous Measurement
In continuous measurement mode, the laser module performs repeated distance measurements on the target. The typical refresh rate is set to 2 Hz or 5 Hz, and the maximum refresh rate can reach 30 Hz (customized version required). The refresh rate can be adjusted via the serial interface.

Electrical Interface Definition

Mechanical Interface

Product Description

The LR1000C3 is a new-generation 905nm compact laser rangefinder module developed for electro-optical equipment that needs reliable ranging in a very small footprint. It is especially suited to thermal imagers, night vision devices, telescopes, laser illuminators and compact UAV payloads, where low weight, simple UART integration and stable 1 km-class performance matter more than heavy long-range military architecture.

The module works at 905 nm ±5 nm and supports a measuring range of 4–1000 m. According to the specification, ranging accuracy is ±1 m up to 500 m, and ±1 m + d×0.1% from 500 m to 1000 m, with a valid measurement rate ≥98% and false alarm rate ≤1%. Beam divergence is <6 mrad, and the receiver aperture is 9.2 mm × 14.5 mm. Those numbers place the LR1000C3 in the class of compact 905 nm OEM rangefinder modules commonly used in handheld optics and observation devices rather than in large fire-control assemblies.

One practical advantage is its adaptive 3–10 Hz ranging frequency. That gives system designers a better balance between responsiveness and power than fixed-rate low-speed modules. The functional set includes single measurement and continuous measurement; for low-reflectivity targets, single-shot mode automatically repeats internally until stable data is obtained, then sends the result in the standard serial format. The manual also notes that higher continuous refresh rates up to 30 Hz are available in customised versions.

Electrically, the LR1000C3 uses a UART-TTL interface with a default baud rate of 115200 bps and a supply voltage of 3.3–5 V. Startup time is ≤200 ms, startup inrush current is about 350 mA, sleep power is <1 mW, standby power is <0.3 W, near-range operating power is <0.5 W, and long-range operating power is <1.2 W. That combination makes it attractive for portable optics, battery-powered surveillance devices and lightweight UAV payloads where every watt is being hunted like a greased ferret.

The protocol is simple and MCU-friendly. It uses an 8-byte frame with 0x55 0xAA header bytes, function code, four data bytes and checksum. Commands include single-shot ranging, continuous ranging, stop ranging, optional angle measurement for versions fitted with an angle sensor, power-on self-test, baud-rate configuration and LD constant-on mode for developers. Returned distance data is transmitted in hexadecimal as actual value ×10, so the host can reconstruct the range with one decimal place.

Mechanically, the module is compact at 30 mm × 19 mm × 29 mm and weighs ≤16 g. It uses a square format rather than the cylindrical body found in some other 905 nm modules, which makes it easier to package into flat optical systems and compact electronic assemblies. The operating temperature range is −20 °C to +55 °C, with −40 °C optional, storage is −40 °C to +60 °C, protection is IP67 inside the lens cavity, shock is 1000 g/ms along the optical axis, vibration is 5–50–5 Hz at 2.5 g, and MTBF is ≥1500 h

For front-window integration, the manual recommends H-K9L optical glass or fused silica, wedge angle tolerance ≤3′, surface roughness around Ra 0.012, and an AR coating for 855–955 nm with transmittance ≥99.5%. After any hydrophobic or hard coatings, total transmittance should remain ≥98%. The guide also specifies keeping window thickness around 2–4 mm, aligning the transmit optical axis parallel to the window normal, and keeping the air gap below 0.5 mm to limit extra loss and back-reflection. That is exactly the sort of unglamorous optical housekeeping that saves range in the real world instead of just in PowerPoint.

The usage notes make the application boundaries very clear. This module is intended mainly for civilian integration in UAVs, outdoor observation devices and surveying or mapping systems, and it is explicitly not for military use in the supplied manual. The document also explains how target reflectivity, angle and weather affect performance: medium-reflectivity targets such as building walls define the nominal spec; high-reflectivity targets can extend range; low-reflectivity targets may reduce it significantly; and rain, fog, snow, haze and direct sunlight all reduce usable distance. For long-distance measurement, ERDI recommends mounting the module on a tripod or stable platform. 

Taken together, the LR1000C3 is best understood as a compact 905nm ranging core for thermal imaging, night vision and portable electro-optical devices: small enough for embedded integration, strong enough for 1 km-class ranging, and simple enough for quick UART-based secondary development. Comparable market offerings in the 905 nm segment are also commonly positioned around handheld optics, thermal imaging and small UAV integration, which matches this product’s practical niche rather well.