Quick Answer
The Emlid Reach RS4 Pro is the newest and most capable receiver, with dual cameras for AR-guided stakeout and image-based measurement. The RS4 shares the same GNSS engine and tilt compensation but without the cameras, making it the better value for most surveyors. The RS3 is the previous generation: still capable with tilt compensation, but it lacks L5/L6 tracking and the upgraded radio of the RS4. The RS2+ is the budget option for surveyors who do not need tilt compensation and are happy with dual-band GNSS only.
At a Glance
| Feature | RS2+ | RS3 | RS4 | RS4 Pro |
|---|---|---|---|---|
| GNSS Bands | L1/L2 | L1/L2/L5 | L1/L2/L5/L6 | L1/L2/L5/L6 |
| Channels | 448 | 555 | 672 | 672 |
| Tilt Compensation | No | Yes (Gen 1 IMU) | Yes (Gen 2 IMU) | Yes (Gen 2 IMU) |
| Cameras | No | No | No | Dual Full HD |
| Radio | LoRa only | LoRa only | LoRa + UHF | LoRa + UHF |
| Battery Life | 16 hrs | 16 hrs | 16 hrs | 16 hrs |
| Weight | 1.04 kg | 1.02 kg | 920 g | 920 g |
| IP Rating | IP67 | IP68 | IP68 | IP68 |
| Storage | 8 GB | 16 GB | 16 GB | 16 GB |
RS4 Pro: The Flagship
The Emlid Reach RS4 Pro adds dual Full HD cameras with a global shutter to the RS4 platform, enabling AR-guided stakeout and image-based measurement.
AR stakeout overlays your design coordinates onto your phone's camera feed, showing exactly where to place a marker. This is useful on construction sites where you need to stake out dozens of points quickly. Image-based measurement lets you capture coordinates of inaccessible points (across a road, at the top of a wall) by pointing the camera and taking a photo.
The rest of the spec matches the RS4: all-band L1/L2/L5/L6 tracking, next-gen IMU tilt compensation, dual LoRa and UHF radios, IP68 magnesium body, and 16-hour battery.
Who should buy it: construction surveyors who stake out frequently, teams doing as-built verification, or anyone who regularly needs to measure points they cannot physically reach. If those workflows do not apply, the RS4 delivers the same accuracy for less.
RS4: The Best Value
The Emlid Reach RS4 gives you the same all-band GNSS engine, next-gen tilt compensation, IP68 magnesium body, and dual radios as the Pro, without the cameras.
The step up from the RS3 is meaningful. The RS4 adds L6 tracking, a faster IMU that initialises in seconds, a 2W UHF radio alongside LoRa, a built-in LTE modem, RS-232 serial port, and lighter weight at 920 g. It performs better in difficult signal environments where the extra channels and L6 make a noticeable difference.
Who should buy it: most surveyors. If you do not need AR stakeout or image measurement, the RS4 is the sweet spot in the range.
RS3: Still Capable, Now Discontinued
The Emlid Reach RS3 tracks L1/L2/L5, has IMU tilt compensation, LoRa radio at 1W, IP68 rating, and 16-hour battery. It delivers the same centimetre-level RTK accuracy as the newer models.
The practical limitations: fewer channels (555 vs 672), no L6 tracking, slower tilt initialisation, LoRa only (no UHF), no built-in LTE, and an older u-blox chip. For day-to-day work these differences are small. The RS3 struggles more in dense tree cover or urban canyons where the RS4's extra channels help.
Who should buy it: surveyors on a tighter budget, or teams expanding an existing RS3 fleet. Stock is limited since Emlid has shifted production to the RS4 line.
RS2+: The Budget Workhorse
The Emlid Reach RS2+ is the oldest model. It tracks L1/L2 only, has no tilt compensation, LoRa radio at 1W, and IP67 body. It is the cheapest option and still delivers centimetre-level accuracy.
The lack of tilt compensation is the main limitation. Without it, you must keep the pole perfectly plumb for every measurement, which slows data collection. The RS2+ also has fewer channels (448) and less storage (8 GB).
The RS2+ works well as a base station. If you pair it with RX or RX2 rovers, the base sits stationary on a known point where tilt compensation is irrelevant.
Who should buy it: those needing a low-cost base station, or anyone who does not need tilt compensation and can accept dual-band tracking.
What About the RX and RX2?
The Reach RX and Reach RX2 are lightweight NTRIP-only rovers. They cannot act as a base station. The RX tracks L1/L2, the RX2 adds L5/L6. They suit GIS teams, utility workers, or as extra rovers alongside an RS-series base.
Which Should You Choose?
If budget allows and you do construction or as-built work, the RS4 Pro is worth it for the cameras. For general surveying, the RS4 is the best all-round choice. For multi-rover setups on a budget, an RS2+ or RS3 as a base with RX2 rovers works well. The Survey Team Kit bundles a base with rovers for this exact use case. Browse the full GPS and GNSS Systems collection or the surveying range to compare options.
All receivers work with the Emlid Flow app (free Standard plan, paid Survey plan) and the Emlid survey pole.
Further Reading
For a closer look at the newest model, our article on using the RS4 Pro for drone mapping covers PPK workflows. The Emlid Reach complete guide explains the basics of RTK for beginners.