> For the complete documentation index, see [llms.txt](https://freegrow-1.gitbook.io/product-docs-en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://freegrow-1.gitbook.io/product-docs-en/en-creator-kit-q1/learn-more/z-axis-installation-notes.md).

# Z-Axis Installation Notes

### **In This Guide**&#x20;

we explain the **anchor installation structure and placement strategy** for improving **Z-axis (height) positioning accuracy** using the **GrowSpace Q1 Kit** in indoor environments.

In spaces where Z-axis accuracy is critical, a simple flat (XY-plane) anchor layout is not sufficient.\
To achieve precise 3D positioning, a **spatial (multi-level) installation structure** is required.

***

### 3D Position Output with the GrowSpace Q1 Kit

With the **GrowSpace Q1 Kit**, you can use a **developer tag** or **listener device** to monitor real-time **3D position data**, including X, Y, and Z coordinates.

#### Example: Serial communication output

```
X: 12.34, Y: 56.78, Z: 9.01
```

For listener devices, this data is provided in the form of **POS messages**, which include X, Y, and Z values.

![](/files/0XGgUF8xM4hBvJvX8hEN)\
This allows you to track not only flat XY positions, but also the **height (floor or level)** of a person or asset in real time.

***

### Installation Structure Affecting Z-Axis Accuracy

The **GrowSpace Q1** system calculates tag positions using **TWR (Time of Flight)**-based distance measurements.\
However, if **all anchors are installed at the same height** (e.g., on the ceiling), the system may encounter the following issues when calculating **Z-axis (height)** values:

#### Problem Scenario

* Even if the tag is located 1 meter above or below the ceiling plane, the measured distance to each anchor remains nearly the same.
* Because there is little to no difference in distance, the system cannot accurately determine the tag’s **Z-axis (height)** position.

<figure><img src="/files/QxubZyXfJaQ27S35dsIZ" alt="" width="375"><figcaption><p>Incorrect Anchor Installation</p></figcaption></figure>

→ As a result, the **Z-coordinate may be fixed at zero** or its accuracy may be significantly reduced.

***

### Anchor Installation for Improved Z-Axis Accuracy

To detect changes along the Z-axis, **anchors must be installed at different heights**.

#### Recommended Placement Strategy

* Place **2 anchors on the ceiling** and **2 on the floor**, arranged in a crisscross pattern
* Alternatively, install anchors at **varied heights** on pillars, walls, or other vertical surfaces

<figure><img src="/files/YZnhzbrDiwc4qPgYmNpv" alt="" width="375"><figcaption></figcaption></figure>

This layout creates measurable **distance differences** between the tag and each anchor based on height, which helps the system **reduce Z-axis positioning errors**

***

### Installation Tips for Large Spaces (40m × 20m or Larger)

In wide areas, using only the four corners for anchor placement may result in reduced accuracy.

#### Recommended Placement Strategy

<table><thead><tr><th width="248.39996337890625">Item</th><th>Details</th></tr></thead><tbody><tr><td>Basic Setup</td><td>Install 4 anchors at the four corners of the space</td></tr><tr><td>Additional Anchors</td><td>Add 2–3 anchors at the center or along the middle of walls</td></tr><tr><td>Height Variation</td><td>Distribute anchors at different levels such as ceiling, pillars, and floor</td></tr><tr><td>Distance Spacing</td><td>Keep the distance between anchors at <strong>15–20 meters or less</strong></td></tr></tbody></table>

<figure><img src="/files/RxOcteUnM40PIGr0xq70" alt=""><figcaption></figcaption></figure>

Install anchors at **varied heights and distributed positions**, as described above.\
This approach ensures a **balanced distribution of distance differences** between the tag and each anchor, improving not only **Z-axis accuracy**, but overall **3D positioning performance**.

***

### Conclusion

The **GrowSpace Q1 Kit** supports 3D positioning by default, but to achieve **accurate Z-axis measurements**, a **spatial anchor layout** is essential.<br>

* Installing all anchors at the same height can lead to significant errors in Z-axis positioning
* Placing anchors at **different vertical levels** helps minimize Z-coordinate errors
* In large spaces, it's also important to **add supplementary anchors** and **maintain balanced spacing**

If your use case requires **precise 3D tracking**, make sure to go beyond flat layouts and apply a **multi-level anchor installation strategy**.
