# Leica GS18 / GS16

The Leica GS18 T, GS16, and GS07 are professional survey-grade GNSS receivers by Leica Geosystems (Hexagon). The GS18 T is the flagship model featuring calibration-free tilt compensation — measure without leveling the pole. These receivers are configured through **Leica Captivate** software running on a CS20 or CS35 controller. The GS07 can also be configured via the Leica Captivate app on a smartphone.

## Requirements

* **Leica GS18 T, GS16, or GS07** powered on with clear sky visibility
* **Leica Captivate** on a CS20 or CS35 controller (or Captivate app for GS07)
* **Internet connection** via phone hotspot over Bluetooth, USB tethering, or controller SIM card
* **RTKdata.com account** with active RTK credentials (username starting with `rtk` and password from your RTK dashboard)
* **Survey pole** with Leica adapter

{% hint style="info" %}
Don't have an RTKdata.com account yet? [Start 30-day Free Trial](https://rtkdata.com/try-rtk-corrections-free-for-30-days/) or [View Pricing](https://rtkdata.com/pricing/)
{% endhint %}

## Step-by-step setup

{% stepper %}
{% step %}

#### Set up internet connection

1. On the CS20/CS35 controller, go to **Settings** → **Connections** → **Internet connections**.
2. Tap **New** to create a new internet profile.
3. Select **Bluetooth** (for phone hotspot) or **USB** (for USB tethering).
4. If using Bluetooth, pair your phone with the controller first under **Settings → Connections → Bluetooth**.
5. Enable your phone's mobile hotspot and confirm the controller shows "Internet connected."

{% hint style="warning" %}
The controller must have an active internet connection before RTK corrections will work. If you see "No internet," verify your phone's hotspot is active and Bluetooth is paired.
{% endhint %}
{% endstep %}

{% step %}

#### Create an RTK rover profile

1. Go to **Settings** → **RTK Rover** → **RTK Network profile**.
2. Tap **New** to create a new profile.
3. Name it **RTKdata**.
4. Set **Network type** to **Direct IP** or **NTRIP**.
   {% endstep %}

{% step %}

#### Enter RTKdata.com NTRIP settings

Fill in the connection fields. Select the tab for your region:

{% tabs %}
{% tab title="North America" %}

* **Host (domain):** `rtk.rtkdata.com`
* **Host (IP fallback):** `13.56.117.10`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}

{% tab title="Europe" %}

* **Host (domain):** `eu.rtkdata.com`
* **Host (IP fallback):** `3.73.41.96`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}

{% tab title="Australia" %}

* **Host (domain):** `aus.rtkdata.com`
* **Host (IP fallback):** `54.206.56.130`
* **Port:** `2101`
* **Username / Password:** From *RTK Credentials* in the internal dashboard (not website login)
* **Mountpoint (ALL CAPS):** `AUTO`
  {% endtab %}
  {% endtabs %}

{% hint style="warning" %}
Type `AUTO` manually in all capital letters. Do not browse the mountpoint table — Leica Captivate may time out or return an empty list if the source table is large.
{% endhint %}
{% endstep %}

{% step %}

#### Configure GGA position sending

1. In the RTK profile settings, ensure **Send GGA position** is set to **On** or **Automatic**.
2. This sends your approximate position to RTKdata so the correct base station corrections are generated for your location.
   {% endstep %}

{% step %}

#### Start the RTK survey

1. Tap **Survey** → **Start** from the main menu.
2. Select the **RTKdata** RTK profile you created.
3. Captivate connects to the internet, then to the NTRIP caster.
4. Watch the solution status in the status bar: **Navigated** → **Float** → **Fixed**.
5. Once Fixed, you are ready to collect points, stake out, or run your survey workflow.
   {% endstep %}
   {% endstepper %}

## GS18 T tilt compensation

The GS18 T features calibration-free tilt compensation using an integrated IMU. Once RTK Fix is achieved, tilt compensation activates automatically — no initialization routine required. You can measure with the pole tilted up to 30 degrees. The controller displays a tilt icon and the compensated position in real time.

## Vertical reference (heights)

{% hint style="info" %}
Heights from RTKdata.com are **ellipsoidal**, not orthometric (mean sea level). Configure a geoid model in Leica Captivate under **Settings → Coordinate system → Height mode** if your project requires orthometric heights.
{% endhint %}

## Troubleshooting

| Problem                     | Cause                                          | Fix                                                                                                    |
| --------------------------- | ---------------------------------------------- | ------------------------------------------------------------------------------------------------------ |
| "No internet connection"    | Phone hotspot not paired or inactive           | Verify Bluetooth pairing between controller and phone. Restart the phone's hotspot.                    |
| Empty mountpoint list       | Source table timeout or wrong host             | Do not browse — type `AUTO` manually in all caps. Verify the host address is correct.                  |
| Wrong network type selected | "Network RTK" instead of Direct IP/NTRIP       | Edit the RTK profile and change the network type. RTKdata is a standard NTRIP caster.                  |
| Stuck on Float              | Poor sky conditions or far from base           | Move to open sky. Check RTKdata base coverage at [rtkdata.com](https://rtkdata.com).                   |
| Credentials rejected        | Using website login instead of RTK credentials | Use the username (starting with `rtk`) and password from your RTK dashboard, not your website account. |

## Tips and tricks

* **Bluetooth internet is the most common setup** — pair your phone once and it auto-reconnects on future surveys.
* **Save the RTK profile** so your entire crew can load it on their controllers without re-entering settings.
* **GS07 users** can configure NTRIP directly in the Leica Captivate app on Android, using the same settings above.
* **Check "Correction age"** on the Captivate status bar. Values above 5 seconds indicate an unstable internet link.
* **For Leica iCON construction receivers**, the same NTRIP settings apply — configure them in iCON field software.
* **Keep firmware updated** via Leica myWorld to benefit from the latest constellation support and RTK improvements.