CONTROL FUNCTIONS
The laser rangefinder/designator can perform the following control functions through a serial interface:
- Respond to a laser ranging command and stop ranging at any time upon receiving a stop command;
- Output one set of range data and status information for each pulse during ranging;
- Support range gating during ranging;
- Automatically stop ranging after 5 minutes (at 1 Hz) or 1 minute (at 5 Hz) if no stop command is received after continuous ranging is initiated;
- Allow configuration of designation mode and code;
- Respond to a laser designation command, perform designation according to the preset mode and code, and stop designation at any time upon receiving a stop command;
- Automatically stop designation after completing one cycle if no stop command is received;
- Output one set of range data and status information for each pulse during laser designation;
- Perform power-on self-test and periodic self-test, and output status information;
- Respond to a self-test command and output status information;
- Report the cumulative number of emitted laser pulses.
TECHNICAL SPECIFICATIONS
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Operating modes
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Ranging, designation
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Pump source
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Diode array
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Operating wavelength
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1.064 µm (1064 nm)
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Pulse energy
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≥ 20 mJ
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Pulse energy fluctuation
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Within one designation cycle, single-pulse energy deviation shall not exceed ±10% of the mean pulse energy (statistics taken after 2 s of emission)
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Beam divergence
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≤ 0.6 mrad
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Pulse width
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10 ± 5 ns
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Laser optical-axis stability
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≤ 0.05 mrad
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Ranging performance
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Ranging frequency:1 Hz / 5 Hz, and single-shot
- Continuous ranging at 1 Hz: duration ≥ 5 minutes, then rest 1 minute.
- Continuous ranging at 5 Hz: duration ≥ 1 minute, then rest 1 minute.
- Minimum measurement range: ≤ 300 m.
- Maximum measurement range: ≥ 3,000 m.
- Ranging accuracy: ±1 m.
- Acquisition rate: ≥ 98%.
- Ranging logic: first and last target.
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Designation performance
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- Laser code accuracy: 2.5 µs.
- Fundamental designation frequency: 20 Hz.
- Designation cycles:
- Short-cycle designation: single designation duration ≥ 20 s, interval ≤ 30 s, continuous for 8 cycles.
- Long-cycle designation: single designation duration ≥ 47 s, repeat start with interval ≤ 30 s, continuous for 2 cycles.
- After completion of one designation cycle, the interval before restarting continuous designation shall be ≥ 30 minutes.
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Laser coding
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a) Complies with weapon system requirements and supports user-defined code expansion.
b) Supports external synchronization signal input to control emission timing for coding.
c) Coding method: precise frequency code (eight groups of pre-stored periodic codes).
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Dimensions and mass
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a) External envelope: ≤ 92 mm × 67 mm × 53 mm
b) Mass: ≤ 290 g
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Power input requirements
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a) Average operating power consumption ≤ 55 W; peak power ≤ 100 W.
b) Operating voltage range: 20 V – 28 V.
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Electrical "three-proof" treatment: circuit boards shall receive conformal coating after design and debugging to provide three-proof protection.
ENVIRONMENTAL ADAPTABILITY REQUIREMENTS
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Temperature Requirements
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High-temperature conditions
- Operating temperature: ≤ +55 °C
- Storage temperature: ≤ +70 °C
Low-temperature conditions
- Operating temperature: ≥ –40 °C
- Storage temperature: ≥ –45 °C
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Vibration Requirements
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- The unit shall withstand flight vibration and the shocks occurring during takeoff and landing. All equipment shall also withstand environmental conditions equivalent to vehicle transportation.
- Vibration type: swept-frequency sinusoidal vibration.
- From 15 Hz to 33 Hz: constant displacement vibration with an amplitude of 0.91 mm.
- From 33 Hz to 700 Hz: constant acceleration vibration with an acceleration of 2 g.
- Duration: 1 hour per axis in three orthogonal directions.
- Test condition:
- The product shall be mounted on the vibration test bench in normal operating configuration and powered on.
- Post-test requirement:
The product shall operate normally after the vibration test.
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Shock Requirements
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- Vertical axis: ≥ 10 g
- Lateral axis: ≥ 10 g
- Longitudinal axis: ≥ 10 g
- Shock waveform: post-peak sawtooth wave, duration 11 ms.
- Each of the X, Y, and Z axes shall be tested in both directions, for a total of 18 shocks.
- Test condition:
- The product shall be mounted on the shock test bench in normal operating configuration and powered on.
- Post-test requirement:
The product shall operate normally after the shock test.
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MECHANICAL INTERFACE
(The mechanical interface defines the physical mounting and alignment requirements of the laser rangefinder/designator. Details such as mounting holes, reference surfaces, and alignment axes should be specified according to the system integration design.)
Unit: mm
PIN INTERFACE
Electrical Interface
Communication interface: RS422
Connector model and interface definition: see Table 1.
Connector: MOLEX 53048-0810
Mating plug: MOLEX 51021-0800
Table 1 — Electrical Interface Definition (TTL)
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Pin No.
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Signal Name
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Description
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1
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Vin
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Power supply +24 V
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2
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Vin
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Power supply +24 V
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3
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GND
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Power return (–)
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4
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GND
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Power return (–)
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5
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RX1+
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Host → Laser rangefinder/designator module (RS-422 RX+)
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6
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RX1–
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Host → Laser rangefinder/designator module (RS-422 RX–)
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7
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TX1–
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Laser rangefinder/designator module → Host (RS-422 TX–)
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8
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TX1+
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Laser rangefinder/designator module → Host (RS-422 TX+)
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External trigger interface:
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Pin No.
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Signal Name
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Description
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1
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TBI
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External trigger + (triggered on rising edge)
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2
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TBG
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External trigger –
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Figure — Electrical Interface Diagram

LDR20K1 20 mJ 1064 nm Laser Target Designator/Rangefinder Module
The LDR20K1 is a compact 20 mJ laser target designator and rangefinder module designed for airborne platforms and other mission-critical electro-optical systems that demand high reliability and precise engagement of laser-guided munitions. It measures target distance and provides coded laser designation within a single integrated unit, featuring small size, low mass, long effective range and strong environmental adaptability for harsh flight and vehicle environments.
Based on a diode-pumped 1064 nm solid-state laser, the LDR20K1 delivers ≥ 20 mJ pulse energy with ≤ 0.6 mrad beam divergence and a pulse width of 10 ± 5 ns, while maintaining laser optical-axis stability within 0.05 mrad. Its ranging performance includes single-shot and continuous modes at 1 Hz and 5 Hz, with a measurement range from ≤ 300 m to ≥ 3,000 m, ±1 m range accuracy and a valid acquisition rate of at least 98%, supporting both first-target and last-target logic for complex scenes such as cluttered backgrounds or partially obscured targets.
For weapon guidance, the module offers precise frequency-coded laser designation with a fundamental designation frequency of 20 Hz and code timing accuracy of 2.5 µs. Short-cycle designation supports ≥ 20 s active time with ≤ 30 s interval for up to 8 consecutive cycles, while long-cycle designation provides ≥ 47 s active time, also with ≤ 30 s interval, for up to 2 cycles; after completing a designation sequence, a cooldown interval of at least 30 minutes is required before restarting continuous designation. The coding scheme uses precise frequency codes with eight pre-stored periodic patterns and supports user-defined code expansion and external synchronization signals to match specific weapon system requirements.
The LDR20K1 is engineered for easy integration into UAV EO/IR gimbals, targeting pods, stabilized turrets and other opto-electronic payloads. The mechanical envelope is ≤ 92 mm × 67 mm × 53 mm, and the module mass is ≤ 290 g, making it well-suited for SWaP-constrained platforms. Power requirements are equally straightforward: average operating power consumption is ≤ 55 W with a peak of ≤ 100 W, over a 20–28 V input range, and all circuit boards receive conformal coating (“three-proof” treatment) for protection against moisture, dust and corrosive environments.
To support long-term field use, the module is qualified over an operating temperature range of −40 °C to +55 °C and storage from −45 °C to +70 °C. It withstands swept-frequency sinusoidal vibration from 15 Hz to 33 Hz at 0.91 mm amplitude and from 33 Hz to 700 Hz at 2 g, for 1 hour per axis in three orthogonal directions, as well as multi-axis shock loads ≥ 10 g with post-peak sawtooth waveforms of 11 ms duration, ensuring stable performance under aircraft take-off/landing and vehicle transport conditions.
Control and data exchange are implemented via a standard RS-422 serial interface using an 8-pin MOLEX 53048-0810 connector (mating plug 51021-0800), with +24 V power input, differential TX/RX pairs, and an external trigger input for synchronized firing. The communication link operates at 115200 bps, 8 data bits, 1 start bit, 1 stop bit, no parity, with LSB-first byte order. The rich command set includes self-test, single and continuous ranging, short/long/single-cycle designation, stop command, range-gate and target-selection configuration, laser code read/write and cumulative pulse count query, while the module continuously reports range and status data for each emission pulse and can perform power-on and periodic self-tests.