Inside the LRF3000A1: 3,000 Metres from 12 Grams
The LRF3000A1 is the module we get asked about most, for good reason: ≥ 3,000 m of range against a 70%-reflectivity building-class target, from a 12-gram, 13.5 × 25.1 × 27.8 mm body, Class 1 eye-safe. Those two numbers — range and weight — don't usually belong in the same sentence for a 905 nm silicon-APD design, so here's how we get there, and what the spec sheet actually commits to once you read past the headline.
Where the weight budget actually goes
At 12 grams, there's no room in the design for anything that isn't earning its place. The transmit path is a single 905 nm laser diode and shaped optics holding beam divergence to ≤ 10 mrad — tight enough to keep energy concentrated on a distant target rather than spreading it across a wide, wasted footprint. The receive path is sized to the smallest aperture that still supports ≥ 98% valid measurement rate at 3,000 m against the reference target; every extra millimetre of aperture buys signal margin but also adds mass and volume, so the aperture is tuned, not maximized. The result is a module that devotes its entire weight budget to the optical and electronic path that actually determines range, with nothing held back for features the flagship's use cases don't need.
Adaptive frequency does the heavy lifting
The LRF3000A1 measures at 3–10 Hz adaptive in normal mode and 1–10 Hz adaptive in long-range mode. That drop to 1 Hz at the top of its envelope isn't a limitation so much as the mechanism that makes 3,000 m possible at all: a weak return from 3 km out needs a longer integration window to separate signal from noise reliably, so the module trades reporting speed for confidence exactly the way we describe generally in How 905 nm DToF laser ranging works. The payoff is a valid measurement rate of ≥ 98% and a false alarm rate of ≤ 1% held across the whole range, not just at close distance.
Reading the accuracy formula honestly
Accuracy is quoted as ±0.7 m out to 100 m, then ±(0.7 + 0.003·d) m beyond. Run that formula at the rated maximum: ±(0.7 + 0.003 × 3000) = ±9.7 m at 3,000 m. We publish that formula rather than a single flattering headline number because it's what lets you design correctly — if your application operates near the top of the range, budget against the 3,000 m figure, not the 100 m one. See Understanding rangefinder accuracy specs for the general reasoning behind why every module on this site quotes accuracy this way.
The full spec sheet
| Maximum ranging distance | ≥ 3,000 m @ 70% refl. building target (clear, visibility ≥ 4 km) |
|---|---|
| Minimum ranging distance | 1 m @ 90% refl. white board |
| Ranging accuracy | d ≤ 100 m: ±0.7 m · d > 100 m: ±(0.7 + 0.003·d) m |
| Measurement frequency | Normal 3–10 Hz adaptive · Long-range 1–10 Hz adaptive |
| Valid measurement rate | ≥ 98% |
| False alarm rate | ≤ 1% |
| Laser wavelength | 905 ± 10 nm, Class 1 (IEC 60825-1) |
| Typical beam divergence | ≤ 10 mrad |
| Interface | UART (TTL 3.3 V), 115200 bps default / 9600 bps |
| Supply voltage | DC 3.3–5 V (ripple < 0.1 V) |
| Operating power | ≤ 1.8 W @25 ℃ · ≤ 2.1 W @70 ℃ · ≤ 1.6 W @-20 ℃ |
| Response time | ≤ 160 ms + 100–517 ms (start-up + first ranging) |
| Weight | 12 ± 0.5 g |
| Dimensions | 13.5 × 25.1 × 27.8 mm |
| Shock / vibration | 1000 g/ms · 5–50–5 Hz, 2.5 g |
| Operating temperature | -20 to +60 ℃ |
| Protection rating | IP67 |
| Reliability | MTBF ≥ 1500 h |
What the envelope trades away — and what it doesn't
Getting 3,000 m out of 12 g means the receiver aperture is smaller than our heavier, shorter-range tube-series modules — that's the physical trade-off behind the size number. What it doesn't compromise on is protocol compatibility: the flagship uses the exact same UART-TTL electrical interface, default baud rate and 8-byte frame format as the rest of the catalog. An OEM that's already integrated a smaller module for a lower-tier product can drop the LRF3000A1 into a flagship variant of the same platform without redesigning the host interface — only the mechanical mounting and the range/accuracy numbers your application logic works against actually change.
How it sits against the rest of the long-range tier
The LRF3000A1 isn't the only long-reach module we build — the E-series adaptive line covers adjacent ground with a different size/range trade-off. The LR2000E2 reaches 2,000 m from a similar ≈10 g rectangular body but with a wider accuracy band at range (d·0.4% beyond 400 m); the LR1500E2 reaches 1,500 m (1,800 m at night) at under 10 g. Both are worth a look if 3,000 m is more reach than your platform actually needs and the small extra size or cost of the flagship isn't buying you anything — the right choice is whichever module's range and accuracy formula clears your requirement with the least margin left on the table, not automatically the longest-reach part in the catalog.
Where it's used
The applications we see most often for this module: handheld optics needing genuine long-range capability in a compact body, survey instruments, UAV payloads where reach matters more than the last gram of weight savings, and embedded electro-optical systems built around a long-range core. If you're integrating for one of these and want to check the accuracy formula against your specific working distance before committing to a design, send us the number — we'll run it with you.