RTK GNSS module
for UAV mapping

Positioning with centimeter accuracy
in RTK and PPK. For precise UAV
mapping with less GCPs.

Baseline up to 100 km in PPK.



PPK mapping with centimeter accuracy. Use fewer GCPs

Why camera synchronization is so important?

Usually autopilot triggers the camera and records the coordinate it has at that moment. When the drone is flying at 20 m/s and GPS works at 5 Hz, that means your autopilot will have position readings only each 4 m, which is not suitable for precise georeferencing. In addition, there is always a delay between the trigger and the actual moment the photo is taken.

Reach eliminates the delay

Reach solves the problem of positioning by connecting directly to the camera hot shoe port, which is synced with the shutter. The time and coordinates of each photo are logged with a resolution of less than a microsecond. This method allows GCPs to be used only to check your accuracy.

Connect Reach to a hot shoe port on a camera

Connect Reach to a hot shoe port on a camera

Every time a photo is taken camera produces a pulse on a flash hot-shoe connector which is synced to a shutter opening.

Fly a drone, Reach will record photo events

Fly a drone, Reach will record photo events

Reach captures flash sync pulses with sub-microsecond resolution and stores them in a raw data RINEX log in the internal memory.

Download logs from Reach and base station

Download logs from Reach and base station

After the flight, get the RINEX logs from your airborne Reach module and a base station (Reach RS, CORS or another receiver).

Process logs and get a file with geotags of photos

Process logs and get a file with geotags of photos

Process RINEX files using free RTKLIB software. The produced file with precise coordinates of the photos can be used for georeferencing.

NTRIP or another Reach as a base station

NTRIP or another Reach as a base station

To calculate centimeter-precise coordinates in PPK and RTK, Reach needs corrections from a base station. It could be either another Reach receiver or an NTRIP service. VRS is also supported.


Reach M2 works seamlessly with other Reach receivers over any link and are compatible with any other receiver that supports RTCM3 and NTRIP.

Reach in action

3DroneMapping completes PPK trials with the average zero mean error in all axes

Luke Wijnberg, 3DroneMapping

As a brief synopsis of the results, the maximum deviation of points was no more than 0.09m in all axes. This is an incredible result given the fact that the average pixel size of the resulting imagery was 0.045m. The average mean error in all axes is just few mm!

Tuffwing gets 4cm precision without GCPs with Emlid Reach RTK

Brian Christal, Tuffwing

Tuffwing recently performed integration of Emlid Reach RTK to enable precision maps to be made without the use of GCPs. The system has been benchmarked by comparing a direct georeferenced model with a set of GCPs, used solely for error detection purposes. The lateral RMS error achieved is just 4cm according to the Pix4D quality report.

Evеnt38 integrates Emlid Reach and starts providing a ready-to-go PPK mapping solution

Jeff Taylor, Event38

In this case study, we produced an orthomosaic in the Drone Data Management System™ with 2.45cm horizontal and 5.08cm vertical RMSE, as compared with a survey-grade GPS on the ground.

Reach in the Emlid Store

The basic features of Emlid Flow are available for free to all Emlid users.

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Reach M2 Datasheet
622 kb


  • Dimensions 56.4 x 45.3 x 14.6 mm
  • Weight 35 g
  • Operating tº -20 to +65 ºC


  • Power supply voltage on
    USB or JST-GH connectors 4.75 - 5.5 V
  • Antenna DC bias 3.3 V
  • Typical current consumption @5V 300 mA


  • Static horizontal 4 mm + 0.5 ppm
  • Static vertical 8 mm + 1 ppm
  • Kinematic horizontal 7 mm + 1 ppm
  • Kinematic vertical 14 mm + 1 ppm


  • LoRa radio (sold separately)
  • Frequency range 868/915 MHz
  • Distance Up to 8 km
  • Wi-Fi 802.11 b/g/n
  • Bluetooth 4.0/2.1 EDR
  • Ports USB, UART, Event


  • Corrections NTRIP, VRS, RTCM3
  • Position output NMEA, LLH/XYZ
  • Data logging RINEX with events
    with update rate up to 10 Hz
  • Internal storage 16 GB


  • Signal tracked GPS/QZSS L1C/A, L2C
    BeiDou B1I, B2I
    Galileo E1B/C, E5b
  • Number of channels 184
  • Update rates 10 Hz GNSS

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