Laser Rangefinder Module 1000 m: LR-Series Compared

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• Application notes

Short answer: ERDILRF’s 1,000 m class module is the LR1000E2 — 905 nm, a 4–1,000 m source-table range, ±1 m accuracy to 400 m, 3–10 Hz adaptive output over UART-TTL at 115200 bps, 3.3–5 V supply, ≤ 10 g, and 25.65 × 13.2 × 24.6 mm. Its LR1200E2, LR1500E2 and LR2000E2 siblings share that interface and footprint but differ in reach, beam width and power.

The four modules in the LR-E2 family

If you are searching for a 1,000 m laser rangefinder module, you will almost certainly end up comparing it against its immediate neighbours — because the 1,200 m, 1,500 m and 2,000 m versions come in the same 25.65 mm-wide package, speak the same serial protocol, and sit within $40 USD of each other on published pricing. The interesting question is not which one reaches furthest, but what you gain or give up by moving one step along the family.

Those are published prices from our model catalogue; confirm current terms in writing before building them into a bill of materials.

Longer range does not mean a tighter beam

This is the most counter-intuitive line in the table, and it is worth pausing on. Beam divergence does not improve as you move up the family. The 1,200 m module has the tightest beam in the group at < 4 mrad, while the 1,000 m module is the widest at < 9 mrad — more than twice as wide. LR1500E2 and LR2000E2 both sit at < 6 mrad.

Divergence sets how large the laser spot is when it arrives at the target, and that decides whether you are measuring the thing you aimed at or an average of it and whatever sits behind it. Multiplying the published divergence by distance (simple arithmetic on the spec, not a manual figure): at 1,000 m the LR1200E2’s < 4 mrad beam illuminates a spot under roughly 4 m across, while the LR1000E2’s < 9 mrad beam covers up to about 9 m. The LR1500E2 ranging module at < 6 mrad reaches roughly a 9 m spot at its own 1,500 m maximum.

The practical consequence: if you need to range a discrete object — a pole, a structure edge, a small surveying target — rather than a broad surface such as terrain or a building face, the narrower beam matters more than an extra 200 m of headline reach. A surveying or mapping payload aimed at specific features is often better served by the LR1200E2 with its < 4 mrad beam than by the shorter-range module.

Read where the accuracy formula actually stops

Each model’s accuracy is a piecewise formula rather than a single number, and the bands do not all cover the model’s full range. Two details worth catching before you size an error budget:

• The formula can stop short of the range spec. LR1200E2 is rated 4–1,200 m, but its accuracy bands are documented for 6–500 m and 500–1,000 m. LR1500E2 is rated 4–1,500 m with accuracy documented over the same 6–1,000 m span. Above 1,000 m those two source tables publish no accuracy figure at all — so if your application genuinely operates out there, ask us to confirm it rather than extrapolating the last band. We would rather hand you a documented gap than an invented number.
• The far-field terms are different shapes. LR1000E2 adds a proportional term on top of the fixed one (±1 m + d·0.1%, so about ±2 m at 1,000 m). LR2000E2 replaces it beyond 400 m with a pure percentage (d·0.4%, so about ±8 m at 2,000 m). Similar-looking spec lines, different arithmetic. Our companion article on reading rangefinder accuracy specs works through why error grows this way.

One figure appears only on the longest module: LR2000E2 publishes its valid measurement rate as ≥ 98% up to 400 m but ≥ 80% from 400–2,000 m. The other three quote ≥ 98% with no far-field derating. If your control loop needs a reading on nearly every cycle at long range, budget for roughly one shot in five returning nothing on the 2,000 m module — that is a design input, not a defect.

Power and thermal envelope

Operating power climbs as you move up the family: under 0.6 W short-range on LR1000E2, around 0.4 W on LR1200E2 and LR1500E2, and roughly 1.2 W on LR2000E2. Sleep power is under 1 mW across the family, and standby is under 0.3 W on LR1000E2 and around 0.2 W on LR1200E2 and LR1500E2 — worth designing around, since a duty-cycled sensor on a battery-powered platform spends most of its life in one of those states rather than ranging.

Size the supply rail for inrush, not average draw. LR1000E2 specifies inrush under 350 mA, LR1200E2 around 350 mA, and LR2000E2 under 400 mA. Startup time is ≤ 200 ms across the family, so do not treat the first reading after power-on as trustworthy. LR1000E2, LR1200E2 and LR1500E2 are specified for −20 to +55 °C with a −40 °C option available as a customisation, while LR2000E2 is specified −20 to +60 °C; storage is −40 to +60 °C throughout.

One host driver covers all four

All four are protocol family A: UART-TTL, 115200 bps, 8 data bits, a fixed 8-byte frame with a 55 AA header, and identical command bytes — 55 AA 88 FF FF FF FF 84 for a single shot, 55 AA 89 FF FF FF FF 85 to start continuous ranging. The returned distance is the actual value multiplied by ten. The integration work you do once therefore carries across the whole family; the frame layout and the transmit-versus-reply checksum trap are covered in our serial protocol and checksum guide.

The 6-pin interface is equally consistent: GND, VCC, a reserved I/O pin, TXD, RXD, and SW-SHOT function enable (active high, with the source noting compatibility with an active-low control requirement). One honest caveat: the manuals state the module supply range as 3.3–5 V but do not separately specify the TXD/RXD logic-level voltage, and we will not infer a signal level from a supply rail. If you are wiring directly to a 5 V host, get that confirmed in writing first. If you are integrating with a flight controller, ArduPilot’s rangefinder documentation covers the serial port setup on that side.

Frequently asked questions

What is the real maximum range of a 1,000 m rangefinder module?

LR1000E2’s source table states 4–1,000 m. Like every datasheet range figure, that is a best case under the manual’s reference conditions — target reflectivity, clear air and normal incidence all move it. Size against your worst-case target, not the headline.

Does the 2,000 m module simply replace the 1,000 m one?

Not cleanly. LR2000E2 doubles the reach for $40 USD more published price, but draws roughly 1.2 W against under 0.6 W short-range, lists its protection rating as on request where the other three publish IP67 inside the lens cavity, and derates its valid measurement rate to ≥ 80% beyond 400 m.

Which module is lightest for a weight-limited payload?

They are effectively identical: ≤ 10 g for LR1000E2, LR1200E2 and LR1500E2, and ≈ 10 g for LR2000E2, all in a 25.65 mm-wide housing (LR2000E2 is 13.05 mm thick versus 13.2 mm for the others). Weight is not the differentiator in this family — power and beam divergence are.

Are these modules eye safe?

All four are specified as IEC Class 1 at 905 nm ± 5 nm. A classification applies to the module as tested; adding your own optics in front of it can change the result, which is why the classification has to be re-established for the finished product. The governing standard is IEC 60825-1.

Can I evaluate one sample before committing to volume?

Yes — sample evaluation is the normal first step, and because the interface is identical across the family, a sample of one model de-risks the others too. Full specifications for the LR1000E2 1,000 m module are on its own catalogue page.

Still deciding between two of these? Send us your target type, worst-case distance and platform power budget, and we will tell you which band of the accuracy formula you are actually operating in — get in touch.