> For the complete documentation index, see [llms.txt](https://docs.rtkdata.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rtkdata.com/integration-hub/lidar-scanners-and-mobile-mapping/geosun-gs-handheld.md).

# GeoSun GS-200G RTK Setup: GS-100G, GS-130G, GeosunMeasure

Connect GeoSun GS-100G, GS-130G and GS-200G handheld LiDAR to RTKdata in GeosunMeasure (formerly GnssMeasure): regional IP, port 2101, AUTO and fix check.

The GeoSun **GS-100G**, **GS-130G** and **GS-200G** are handheld SLAM LiDAR scanners from GeoSun's G-series with a built-in GNSS module. This GeoSun GS-200G RTK setup also applies to the GS-100G and GS-130G. All three scan in SLAM, RTK-SLAM or PPK-SLAM mode and are operated from an Android phone on the handle. For RTK-SLAM you enter the NTRIP settings in GeoSun's app **GeosunMeasure** (called **GnssMeasure** in 2024), and the phone provides the internet connection for the corrections.

GeoSun's own RTK setup video tells users to enter an IP address, not a domain name, in the app's **IP Address** field. This guide therefore puts the IP address first: RTKdata documents a fixed IP fallback for each regional server, and that address goes into **RTK Settings**:

| Field                         | Value                                                                                                                                                          |
| ----------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **IP Address**, North America | `13.56.117.10` (IP fallback of `rtk.rtkdata.com`)                                                                                                              |
| **IP Address**, Europe        | `3.73.41.96` (IP fallback of `eu.rtkdata.com`)                                                                                                                 |
| **IP Address**, Australia     | `54.206.56.130` (IP fallback of `aus.rtkdata.com`)                                                                                                             |
| **Port Number**               | `2101`                                                                                                                                                         |
| **Mount Point**               | `AUTO`, in capital letters (alternatives: `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`)                                                                      |
| **Account**                   | NTRIP username from *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/) (starts with `rtk`), not your website login |
| **Password**                  | NTRIP password from *RTK Credentials*, not your website password                                                                                               |

Select the tab for the RTKdata server closest to your work area:

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

* **Host (IP fallback):** `13.56.117.10`, in the field **IP Address**
* **Host (domain):** `rtk.rtkdata.com`, for reference only: GeoSun asks for an IP address in **IP Address**
* **Port:** `2101`, in **Port Number**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login, in **Account** and **Password**
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, in **Mount Point**
  {% endtab %}

{% tab title="Europe" %}

* **Host (IP fallback):** `3.73.41.96`, in the field **IP Address**
* **Host (domain):** `eu.rtkdata.com`, for reference only: GeoSun asks for an IP address in **IP Address**
* **Port:** `2101`, in **Port Number**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login, in **Account** and **Password**
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, in **Mount Point**
  {% endtab %}

{% tab title="Australia" %}

* **Host (IP fallback):** `54.206.56.130`, in the field **IP Address**
* **Host (domain):** `aus.rtkdata.com`, for reference only: GeoSun asks for an IP address in **IP Address**
* **Port:** `2101`, in **Port Number**
* **Username / Password:** From *RTK Credentials* in your [account dashboard](https://rtkdata.com/my-account/rtk-credentials/), not your website login, in **Account** and **Password**
* **Mountpoint (ALL CAPS):** `AUTO` (recommended), or `AUTO_WGS84`, `AUTO_ITRF2020`, `AUTO_ITRF2014`, in **Mount Point**
  {% endtab %}
  {% endtabs %}

## Requirements

* **GeoSun GS-100G, GS-130G or GS-200G** (GS-120G, GS-122G and GS-203G: see the model table below)
* **TF card** inserted in the scanner
* **GS-100G and GS-130G:** GNSS antenna fitted on top and the phone connected with the USB cable
* **Android phone** with **GeosunMeasure** (formerly GnssMeasure) in the phone holder. The app is not in Google Play or the App Store, see the FAQ below.
* **Internet on the phone.** **GS-200G:** mobile data (SIM with a data plan), because the phone's Wi-Fi is connected to the scanner.
* **RTKdata account** with active RTK credentials (username starts with `rtk`)
* **RTKdata coverage** at your site: check the [coverage map](/get-started/coverage-map.md) before you go
* **Open sky** where the scan starts and where it ends

App version shown on the start screen in GeoSun's GS-200G operation demo (July 2025): `v2.1.0_20250711.1349`. The app looks different by model and version: the GS-200G app (v2.1.0) has a **Check** tab and an **Output absolute** switch, while the USB app in GeoSun's 2024 and 2025 videos shows only the tabs **Basic**, **RTK** and **Firmware**.

{% 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 %}

## Which GeoSun handheld models does this guide cover?

This guide covers the GeoSun GS-100G and GS-130G, which pair with the phone over USB, and the GS-200G, which pairs over the scanner's Wi-Fi; all three take their RTKdata settings in GeosunMeasure.

| Model                        | Pairs with the phone via        | Status of the steps on this page                                                                                                                                                  |
| ---------------------------- | ------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| GS-100G                      | USB cable, **USB Connect**      | Documented by GeoSun                                                                                                                                                              |
| GS-130G                      | USB cable, **USB Connect**      | Documented by GeoSun                                                                                                                                                              |
| GS-200G (also written GS200) | Scanner Wi-Fi, **WIFI Connect** | Documented by GeoSun                                                                                                                                                              |
| GS-120G, GS-122G             | Not documented                  | GeoSun lists them in the same G-series and shows the GS-120G with the app in its anchor collection video. GeoSun does not document how they pair.                                 |
| GS-203G (listed as GS-203)   | Not documented                  | GeoSun lists it with "GNSS RTK integrated". No manual or app screens published yet. The steps on this page come from GeoSun's documentation for the GS-100G, GS-130G and GS-200G. |

For other scanners, see [LiDAR Scanners & Mobile Mapping](/integration-hub/lidar-scanners-and-mobile-mapping.md).

## Why does GeosunMeasure need an IP address instead of a hostname?

GeosunMeasure gets an RTKdata IP address instead of a hostname because GeoSun instructs users to put an IP address, not a domain name, into the app's **IP Address** field: the on-screen captions of GeoSun's video *How To Do the RTK Setting of our Handheld LiDAR on the GnssMeasure APP* (September 2024) say "the IP mode don't input the string like the domain name".

The field keeps the label **IP Address** in the 2025 app and in the GS-200G manual, and every GeoSun example shows a numeric IP. GeoSun does not document what the app does with a hostname.

Other RTKdata guides enter the regional hostname (`rtk.rtkdata.com`, `eu.rtkdata.com` or `aus.rtkdata.com`). [NTRIP Server Settings](/get-started/network.md) lists a fixed IP fallback next to each hostname and explains when to use it: "Some older Android controllers, tablets, and embedded systems cannot resolve DNS hostnames. If your device fails to connect using the hostname, enter the IP address instead." In GeosunMeasure you enter that IP fallback directly.

{% hint style="info" %}
If the connection fails, compare the **IP Address** in the app with the values on this page.
{% endhint %}

## Which RTKdata IP address do you enter?

Enter the IP address of the RTKdata server closest to your work area: `13.56.117.10` for North America, `3.73.41.96` for Europe or `54.206.56.130` for Australia, each with **Port Number** `2101` and **Mount Point** `AUTO`.

All three servers share the same global base station network, and the difference is routing latency, as [NTRIP Server Settings](/get-started/network.md) explains. If you work outside these three regions, for example in Latin America, Africa, the Middle East or Asia, you also enter the IP address of the server closest to your work area. `AUTO` picks the base station and the regional datum from the scanner's position.

{% hint style="warning" %}
**One login per connected device.** One set of NTRIP credentials allows one connection at a time, so a scanner and a GNSS rover that are online together need one data stream each. See [Account & Credentials](/get-started/account-and-credentials.md#using-one-subscription-with-several-devices).

Type the username and password rather than pasting them, with no spaces at the start or end. Credentials are case sensitive.
{% endhint %}

{% hint style="info" %}
The RTKdata sourcetable loads without a login. If you test the address in another NTRIP app first, a visible mountpoint list proves neither that your credentials work nor that corrections flow (checked on 25 September 2026). In GeosunMeasure, only a rising **RTCM** counter shows that corrections arrive.
{% endhint %}

## How do you enter GeoSun GS-200G RTK settings in GeosunMeasure?

In GeosunMeasure you tap the gear icon at the top right, open the **RTK** tab and enter your RTKdata values in every field of **RTK Settings** before you tap **CONNECT**. The same steps apply to the GS-100G and GS-130G; only the pairing differs.

{% stepper %}
{% step %}

### Give the phone an internet connection

* The phone needs internet for RTK. GeoSun's GS-200G manual: "Ensure your phone has network connectivity before using RTK."
* **GS-200G:** the phone's Wi-Fi connects to the scanner, and the manual asks you to remove any other Wi-Fi connection on the phone. Office Wi-Fi, site Wi-Fi or a hotspot from another phone therefore cannot supply the internet. Use mobile data from a SIM with a data plan.
* Check that the internet works in the phone's browser before you pair the scanner. A working browser does not prove that port 2101 is open: some mobile carriers block it, see [NTRIP Server Settings](/get-started/network.md#connection-basics).
  {% endstep %}

{% step %}

### Power on and pair the phone

1. **GS-100G, GS-130G:** fit the GNSS antenna on top and connect the phone with the USB cable.
2. Power on the scanner. **GS-200G:** hold the power button for 3 seconds; the power LED lights green and the Wi-Fi LED blinks. **GS-130G:** all four status LEDs light up together, then two stay lit.
3. Open **GeosunMeasure**. On first start, allow location access with **Precise location**, as the GS-200G manual asks.
4. Pair the phone:
   * **USB models:** wait until **USB Connect** turns blue, tap it and confirm the Android prompt with **OK**.
   * **GS-200G:** tap **WIFI Connect**, pick your scanner in the **Device list** (the entry ends in the last three digits of the serial number, for example `AGS-200G-180`) and confirm the Android dialog **Connect to device** with **Connect**.
5. Wait for **Connection successful** and **Initialization of parameters completed** in the status bar.

{% hint style="info" %}
**GS-200G:** keep the phone in the holder on the scanner. GeoSun's manual describes the Wi-Fi data link as smooth within 5 m.
{% endhint %}
{% endstep %}

{% step %}

### Open RTK Settings

Tap the gear icon (**Settings**) at the top right and choose the **RTK** tab on the left. **RTK Settings** opens. The other tabs are **Basic**, **Firmware** and, in the GS-200G app (v2.1.0), **Check**.
{% endstep %}

{% step %}

### Overwrite the pre-filled values and connect

The fields come pre-filled with another service's values (`203.107.45.154`, `8002`, `AUTO`). Replacing only **Account** and **Password** leaves the app pointed at that service, so enter the values from the table at the top of this page in all five fields:

* **IP Address:** the RTKdata IP address for your region (`13.56.117.10`, `3.73.41.96` or `54.206.56.130`), replacing `203.107.45.154`
* **Port Number:** `2101`, replacing `8002`
* **Mount Point:** `AUTO`, in capital letters. The pre-filled `AUTO` comes with the other service's settings and happens to match the RTKdata mountpoint name, so it can stay as long as it reads exactly `AUTO`. Enter `AUTO_WGS84` or `AUTO_ITRF2020` here only if the project stays in WGS84 or ITRF (see PointCloudCreater below).
* **Account** and **Password:** your NTRIP credentials from *RTK Credentials*, typed, with no spaces at the start or end

Leave **Output absolute** at its default (off) unless you need a coordinate file on the phone. According to GeoSun's manual, the switch writes absolute RTK coordinates to `Internal Storage/Documents/Geosun/mobile/project/[Project_Name]/RtkCoord` on the phone, not to the scanner's card.

Tap **CONNECT**. The app returns to the main view and shows **RTK server connection successful** (the manual words it *RTK Service Connected Successfully*). If it stays in Settings, tap **RETURN**.

{% hint style="warning" %}
**The success message only shows that the app reached the server.** It does not prove that your credentials, the mountpoint or the corrections are right, and it appears while the status bar still shows `Satellites:0`. The `AUTO` mountpoint picks the base station from the scanner's position (NMEA GGA). Without a position the login still succeeds, but no corrections arrive, see [NTRIP & GGA Essentials](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md). **RTK Settings** has no GGA option, and GeoSun does not document whether GeosunMeasure sends the position. Work under open sky so the scanner can get its own position, and check the result in the next section: a rising **RTCM** counter and **RTK:Fixed Solution**.
{% endhint %}
{% endstep %}
{% endstepper %}

## How do you know corrections arrive and the scanner is fixed?

RTKdata corrections arrive when the **RTCM** counter in the GeosunMeasure status bar keeps rising, and the GeoSun scanner is fixed when the status bar shows **RTK:Fixed Solution** instead of **RTK:Single Point**. Check both at **Device Ready**, before you start walking.

| Status bar item                               | What to look for                                                                                                                                                                                    |
| --------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **RTCM**                                      | Counter for incoming correction data. It has to rise during initialization, after **Device Start**.                                                                                                 |
| **Diff Age**                                  | Age of the corrections. GeoSun and dealer videos show `00` to `03` at a fix.                                                                                                                        |
| **Satellites**                                | Satellite count. `0` right after **CONNECT** is normal; GeoSun and dealer videos show 20 to 27 at a fix.                                                                                            |
| **RTK:Single Point** / **RTK:Fixed Solution** | Solution status. Start walking only when **RTK:Fixed Solution** shows and the scanner is ready: **Device Ready** on the GS-200G (about 40 s), the T LED solid on the USB models (about 80 to 90 s). |

In GeoSun's GS-130G video the status bar reads `RTCM:102 Device Ready`, then `Diff Age:03 Satellites:20 RTK:Fixed Solution`.

{% hint style="info" %}
**Read the status bar before you start walking, not during the scan.** In the scanning footage of GeoSun's GS-130G video, the status bar shows `RTCM:0` and `RTK:Single Point` during **Device Scanning...**. GeoSun does not document whether this is only a display state, so the status bar during the scan is not a reliable fix check.
{% endhint %}

{% stepper %}
{% step %}

### Start a project in Outdoor mode

1. Hold the red button on the right.
2. Enter **Project Name** and **Engineering Name**. Both are required and accept only letters, numbers and underscores, for example `Site_01`. Tap **Confirm**.
3. Choose **Outdoor (Garden, Natural Scenery)**. GeoSun recommends Outdoor for RTK and PPK. The app sends the start command and shows **Device Start**.
   {% endstep %}

{% step %}

### Hold still until Device Ready and RTK:Fixed Solution

* Set the scanner down and keep it still during initialization:
  * **GS-200G:** about 40 seconds, until **Device Ready** and the message "The equipment is ready. Please start the dynamic measurement."
  * **USB models:** about 80 to 90 seconds, until the T LED stays solid. In GeoSun's GS-100G CORS setup video, the speaker says to wait about 80 seconds and then another 60 seconds.
* In RTK mode the scanner counts as initialized only when **RTK:Fixed Solution** shows (GeoSun). Watch the **RTCM** counter rise while you wait.
* The first **RTK:Fixed Solution** alone is not the signal to go. Keep still until the fix and the ready signal (**Device Ready** or the solid T LED) both show.
  {% endstep %}

{% step %}

### Scan and finish

* Short RTK dropouts of less than 30 seconds can generally still be resolved, according to GeoSun's GS-100G usage instructions. Plan the route so that GNSS shadows under buildings or through passages stay shorter.
* GeoSun's GS-200G manual recommends recordings of up to 30 minutes and, for large areas, blocks with at least 25% overlap.
* If the route moves from outdoors into a building, GeoSun's GS-200G manual says to choose the indoor mode when you process the data.
* End the scan where there is GNSS reception, not in a hall, an underground car park or an underpass. The GS-100G usage instructions warn that shutting down after moving from GNSS reception into an area without it leaves data that cannot be resolved.
* Stop recording by holding the red button until the app reports that the project is completed (GS-200G manual and GeoSun's GS-130G video).
* In RTK mode, close GeosunMeasure first, then power off the scanner (GS-100G usage instructions).
  {% endstep %}
  {% endstepper %}

## Why does GeosunMeasure connect but the GS-200G gets no RTK fix?

When GeosunMeasure connects but the scanner gets no RTK fix, check the **RTCM** counter first: if it does not rise, no corrections arrive (no position yet, a pre-filled value, the mountpoint or the credentials); if it rises but the status stays **RTK:Single Point**, look at the sky view and the antenna. The table also covers pairing and project errors on the GS-200G, GS-100G and GS-130G.

| Problem                                                         | Likely cause                                                                                                                                                                                                                                 | Fix                                                                                                                                                                                                                                                                                                                                                                   |
| --------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| No success message after **CONNECT**                            | No internet on the phone, a mobile carrier that blocks outbound port 2101 (see [NTRIP Server Settings](/get-started/network.md#connection-basics)), a wrong **IP Address** or **Port Number**, or website login instead of NTRIP credentials | Check the phone's internet connection (GS-200G: mobile data, no other Wi-Fi). Check the IP address for your region and port `2101`. Re-type the credentials from *RTK Credentials*. If all values are right, try a different network; on the GS-200G that means mobile data from another carrier.                                                                     |
| Success message, but **RTCM** does not rise                     | No position from the scanner yet (obstructed sky, `Satellites:0`), a pre-filled value left in a field, **Mount Point** not exactly `AUTO`, or website login instead of NTRIP credentials                                                     | Move under open sky and check the **Satellites** count first. Then overwrite **IP Address** and **Port Number** again, check that **Mount Point** reads `AUTO` in capital letters, re-type the credentials from *RTK Credentials* and tap **CONNECT** again. If the counter still stands, send <support@rtkdata.com> the time of the attempt and your NTRIP username. |
| **RTCM** rises, but the status stays **RTK:Single Point**       | Obstructed sky, or no GNSS antenna fitted on a USB model                                                                                                                                                                                     | Start in open sky, check the antenna, and keep the scanner still until the fix. If it persists under open sky with the antenna fitted, send <support@rtkdata.com> the scanner model; see [Correction format](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md#correction-format) in NTRIP & GGA Essentials.                              |
| **RTK Settings** has no **IP Address** or **Port Number** field | Older app version                                                                                                                                                                                                                            | Ask your GeoSun sales representative or engineer for the current GeosunMeasure version.                                                                                                                                                                                                                                                                               |
| The GS-200G does not appear in the **Device list**              | Possible cause: location access. GeoSun's manual asks you to allow **Precise location** on first start.                                                                                                                                      | Allow **Precise location** for GeosunMeasure in the Android settings and reopen the app.                                                                                                                                                                                                                                                                              |
| The red button does not open a new project                      | No TF card inserted. In the GS-200G app, the **Check** tab reports `TF Card Not Detected - Project creation disabled`                                                                                                                        | Insert the TF card. In the GS-200G app, open the **Check** tab again to confirm.                                                                                                                                                                                                                                                                                      |
| The project name is rejected                                    | Spaces or special characters                                                                                                                                                                                                                 | Use only letters, numbers and underscores.                                                                                                                                                                                                                                                                                                                            |
| Corrections stop when a second device connects                  | Two devices on one set of credentials                                                                                                                                                                                                        | One connection per data stream. See [Account & Credentials](/get-started/account-and-credentials.md#using-one-subscription-with-several-devices).                                                                                                                                                                                                                     |

For more checks when the login works but no corrections arrive, see [Fix NTRIP Connection Issues](/support/common-connection-issues.md).

## Which coordinate settings do you use in PointCloudCreater?

For a delivery in your national system, connect with the RTKdata `AUTO` mountpoint and, in PointCloudCreater (PCC), GeoSun's Windows processing software, only project the result and declare it in the regional datum that `AUTO` delivers, for example ETRS89 (realization ETRF2000) in Europe, NAD83(2011) in the USA or GDA2020 in Australia. Use `AUTO_WGS84` or `AUTO_ITRF2020` only for projects that stay in a global frame.

PCC sets the output under **Coordinate** with **Coor. System** (`WGS84 Gauss Local`, `WGS84 Gauss 3-Degree`, `WGS84 Gauss 6-Degree`, `WGS84 UTM`, `AnchorSys` or a user-defined system) and **Coor. Format** (`ENH`), as GeoSun shows in its PPK-SLAM guide.

{% hint style="warning" %}
**Choose the mountpoint by the frame of your delivery, and keep one mountpoint per project.**

1. **Mountpoint `AUTO` for deliveries in your national system:** RTKdata delivers your region's datum, for example NAD83(2011) in the USA, NAD83(CSRS)v7 in Canada, ETRS89 (realization ETRF2000) in Europe and GDA2020 in Australia. [Coordinate Systems & Datums](/get-started/coordinate-systems-and-datums.md) lists the datum and epoch for every region; for regions not listed there, `AUTO` falls back to WGS84(G2139) at the mid-year epoch. In PCC, only project and declare the delivery in that regional datum, even if PCC names the system `WGS84 UTM`.
2. **Mountpoint `AUTO_WGS84` or `AUTO_ITRF2020` only if the project stays in WGS84 or ITRF,** for example when you merge the scan with global-frame data. `AUTO_WGS84` delivers WGS84(G2139) in the middle of the current year, `AUTO_ITRF2020` delivers ITRF2020 at the current epoch. GeoSun's PCC videos show ellipsoid and projection settings but no choice of datum realization (ITRF, ETRS89, NAD83), so do not rely on PCC to convert a global-frame scan to your national datum.

`AUTO_ITRF2014` (ITRF2014 at the current epoch) is also available for projects in ITRF2014. A consistent offset of 50 cm to 1 m against local control usually means a datum mismatch. GeoSun does not document whether PCC uses the real-time RTK solution for RTK-SLAM processing, so check one known control point before delivery.
{% endhint %}

* **Install PCC on a drive other than C: or run it as administrator.** GeoSun's support FAQ reports that on drive C (Windows 10 and later) the coordinate system falls back to WGS84 after you save it as default, or the software crashes when you change it. Check the selected system before every calculation.
* **Set the start position in Shuttle.** In GeoSun's anchor processing tutorial, **Tools** > **Shuttle** > **Configuration**, tab **INS**, the fields **Original Latitude (deg)** and **Original Longitude (deg)** are preset to 30 and 114, and GeoSun changes them to the local latitude and longitude.
* **Replace the China presets in the projection.** In the same tutorial, the **Coordinate system conversion tool** starts with the target `CGCS2000` and **Lon of natural origin** `114`. GeoSun sets the source and target ellipsoid to `WGS84` and the central meridian to the local longitude. For a national grid, enter every parameter of its published definition, not only the local longitude; see [Building a Projection by Hand](/get-started/coordinate-systems-and-datums.md#building-a-projection-by-hand) in Coordinate Systems & Datums.
* **Anchor points from a separate GNSS rover:** connect the rover to the same RTKdata mountpoint as the scanner.

For the datum choice in SLAM point clouds in general, including WGS84 labels in scanner software, see [Georeference SLAM Point Clouds with RTK](/integration-hub/lidar-scanners-and-mobile-mapping/georeferencing-slam-point-clouds-with-rtk.md).

{% hint style="info" %}
RTKdata corrections deliver **ellipsoidal heights**, not heights above mean sea level. GeoSun does not document whether PCC outputs `ENH` heights as ellipsoidal heights or applies a geoid, so compare the result with a control point of known height. See [Understanding Heights](/get-started/understanding-heights.md).
{% endhint %}

## Frequently asked questions

### How do I connect a GeoSun GS-200G to an NTRIP RTK service?

Pair the GS-200G with GeosunMeasure over **WIFI Connect**, open the gear icon, choose the **RTK** tab, fill in **IP Address**, **Port Number**, **Mount Point**, **Account** and **Password**, overwriting the pre-filled `203.107.45.154` and `8002`, and tap **CONNECT**. Then start a project and hold the scanner still until **Device Ready** and **RTK:Fixed Solution** both show. For RTKdata the values are the IP address of the server closest to your work area (North America `13.56.117.10`, Europe `3.73.41.96`, Australia `54.206.56.130`), port `2101` and mountpoint `AUTO`. The phone needs mobile data, because its Wi-Fi is connected to the scanner.

### Can I enter a hostname in the GeosunMeasure IP Address field?

GeoSun advises against it: its RTK setup video tells users not to enter a domain name in the **IP Address** field. In GeosunMeasure, enter the IP fallback that RTKdata documents for the regional server instead: `13.56.117.10` for North America (`rtk.rtkdata.com`), `3.73.41.96` for Europe (`eu.rtkdata.com`) or `54.206.56.130` for Australia (`aus.rtkdata.com`). GeoSun does not document what the app does with a hostname.

### Why does GeosunMeasure say RTK server connection successful but I get no fix?

**RTK server connection successful** only shows that the app reached the server. It does not prove that your credentials, the mountpoint or the corrections are right, and it appears while the status bar still shows `Satellites:0`. Corrections arrive only when the **RTCM** counter rises, and the scanner is fixed only at **RTK:Fixed Solution**; read both at **Device Ready**, before you start walking. With RTKdata, the `AUTO` mountpoint needs the scanner's position before corrections flow, so work under open sky and check that **IP Address** shows the RTKdata server for your region (`13.56.117.10`, `3.73.41.96` or `54.206.56.130`), **Port Number** `2101` and **Mount Point** exactly `AUTO`. Re-type **Account** and **Password** from *RTK Credentials*, not your website login. GeoSun describes a GS-100G support case without a fixed solution that was solved by changing the mountpoint.

### Where do I get the GeosunMeasure app?

GeosunMeasure (formerly GnssMeasure) is not in Google Play or the Apple App Store under either name (checked on 25 September 2026). GeoSun says: "If you've purchased our SLAM LiDAR, our technical team will assist you with the app installation." GeoSun also says you can ask your designated sales representative or engineer for the latest download link. GeoSun documents the app for Android phones. Once installed, the RTKdata settings go into **RTK Settings** as described above.

### Does the GeoSun GS-203G have built-in RTK?

GeoSun's listing of the GS-203G describes it as integrating LiDAR, GNSS and INS, building on the GS-200G, and states "GNSS RTK integrated: Yes". GeoSun has not published a manual or app screens for the GS-203G yet, so its app and pairing are not confirmed. The steps on this page come from GeoSun's documentation for the GS-100G, GS-130G and GS-200G. Until GeoSun documents the GS-203G, the RTKdata connection values on this page apply: the IP address for your region, port `2101`, mountpoint `AUTO` and your NTRIP credentials.

## Related Guides

* [LiDAR & SLAM Scanner RTK Setup](/integration-hub/lidar-scanners-and-mobile-mapping.md): all scanner guides and the common RTKdata settings
* [NTRIP Server Settings](/get-started/network.md): regional hostnames, their IP fallbacks, port 2101 and which server to choose
* [NTRIP & GGA Essentials](/integration-hub/ntrip-clients-and-field-software/ntrip-and-gga-essentials.md): why the `AUTO` mountpoint needs the scanner's position before corrections flow
* [Coordinate Systems & Datums](/get-started/coordinate-systems-and-datums.md): which datum and epoch `AUTO` and its variants deliver in each region, and how to build a projection by hand
* [Georeference SLAM Point Clouds with RTK](/integration-hub/lidar-scanners-and-mobile-mapping/georeferencing-slam-point-clouds-with-rtk.md): datum choices for SLAM scans and WGS84 labels in scanner software
* [Understanding Heights](/get-started/understanding-heights.md): why RTKdata delivers ellipsoidal heights and how to apply a geoid
* [Account & Credentials](/get-started/account-and-credentials.md): where to find RTK Credentials, and one connection per data stream
* [Fix NTRIP Connection Issues](/support/common-connection-issues.md): what to check when the login works but no corrections arrive
* [Coverage Map](/get-started/coverage-map.md): how to check RTKdata coverage at your site before field work

## Quick reference

1. **Phone:** GeosunMeasure (formerly GnssMeasure) on Android with internet (GS-200G: mobile data, no other Wi-Fi).
2. **Pair:** **USB Connect** (GS-100G, GS-130G) or **WIFI Connect** (GS-200G), then gear icon > **RTK** > **RTK Settings**.
3. **Values:** **IP Address** `13.56.117.10` (North America, `rtk.rtkdata.com`), `3.73.41.96` (Europe, `eu.rtkdata.com`) or `54.206.56.130` (Australia, `aus.rtkdata.com`), **Port Number** `2101`, **Mount Point** `AUTO`, **Account** and **Password** from *RTK Credentials*, then **CONNECT**.
4. **Fix:** new project in **Outdoor (Garden, Natural Scenery)**, hold still until **RTK:Fixed Solution** shows and the scanner is ready (GS-200G: **Device Ready**, about 40 s; USB models: T LED solid, about 80 to 90 s), with the **RTCM** counter rising. Check before you start walking, not during the scan.
5. **PCC:** `AUTO` with the regional datum declared for deliveries in your national system; `AUTO_WGS84` or `AUTO_ITRF2020` only for projects that stay in WGS84 or ITRF; check a control point.


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