## Geodetic Calculator

The Geodetic Calculator solves the direct (forward) and inverse (reverse) geodetic problems.

| Menu path |
|-------------|
| {{ menu }} → **Tools** → **Geocalculator** |

The calculator solves problems on a plane (rhumb line) and on a sphere (great circle).

```{hint}
It is recommended to use coordinates in the ENC coordinate system — **WGS 84** — for calculations.
```

### To calculate

1. Select **Task type**
2. Select **Line type**
3. Enter input data (**Input data**)
4. Press **Calculate**

![Direct geodetic problem — rhumb line](images/direct-rumb-line.png)

![Direct geodetic problem — great circle](images/direct-great-circle.png)

![Inverse geodetic problem — rhumb line](images/inverse-rumb-line.png)

![Inverse geodetic problem — great circle](images/inverse-great-circle.png)

| № | Element | Description |
|---|---------|----------|
| **1** | **Direct** | Select to solve the direct geodetic problem |
| **2** | **Inverse** | Select to solve the inverse geodetic problem |
| **3** | **Rumb Line** | Select to solve the problem on a plane |
| **4** | **Great Circle** | Select to solve the problem on a sphere |
| **5** | **Origin point coordinates** | Coordinates of the origin point from which the problem is solved |
| **6** | **Direction** | Direction from the origin point (for the direct problem) |
| **7** | **Distance** | Distance from the origin point (for the direct problem) |
| **8** | **Result** | Coordinates of the geodetic line endpoint (for the direct problem) |
| **9** | **Calculate** | Press to calculate |
| **10** | **Point №1 coordinates** | Coordinates of the first point (for the inverse problem) |
| **11** | **Point №2 coordinates** | Coordinates of the second point (for the inverse problem) |
| **12** | **Direction from Point №1 to Point №2** | Calculated direction (for the inverse problem) |
| **13** | **Reverse direction** | Calculated reverse direction from Point №2 to Point №1 (for the inverse problem) |
| **14** | **Distance between points** | Calculated distance between Point №1 and Point №2 (for the inverse problem) |

### Direct geodetic problem

Input data for the **Direct geodetic problem**: origin point coordinates, direction, and geodetic line length.

**Result:** endpoint coordinates.

**Line types:**

- **Rhumb line** — calculation on a plane
- **Great circle** — calculation on a sphere

### Inverse geodetic problem

Input data for the **Inverse geodetic problem**: coordinates of the start and end points of the geodetic line.

**Result:** direction and length of the geodetic line.

**Line types:**

- **Rhumb line** — calculation on a plane
- **Great circle** — calculation on a sphere

```{note}
After performing the calculation, the input data is not cleared. This allows you to perform a series of calculations with parameter adjustments.
```

```{tip}
**For precise navigational calculations**, it is recommended to use the great circle, as it accounts for the Earth's sphericity and provides more accurate results for long distances.
```

```{tip}
**For short-distance calculations** (up to 100 nautical miles), the rhumb line can be used, which simplifies calculations and provides sufficient accuracy.
```
