Locate

In GIS work, "locating" usually means placing a known position on the map quickly and moving the map view near that position for viewing, checking, and follow-up operations.

The Locate feature in iXGIS is essentially a coordinate positioning tool. It lets you enter longitude and latitude coordinates, or pick a location directly on the map, then pans the map to the target point and displays the address information for that point.

This address information is not entered manually. It is retrieved with reference to the Tianditu reverse geocoding service. Reverse geocoding means converting a longitude and latitude coordinate into a readable address description, such as a city, district, road, and house number, or a location near a road or a certain distance northeast of a POI.

Therefore, the Locate feature in iXGIS does two things:

• Moves the map to a specified coordinate.
• Converts the coordinate into a readable address to help users understand the current location.

1. When to Use Locate

Locate is most useful in these scenarios:

1. You know a longitude and latitude coordinate and want to jump to the exact position on the map.
2. You want to check the approximate address or nearby features for a coordinate point.
3. You are organizing field records, monitoring points, sampling points, or issue points and need to inspect their locations quickly.
4. You need coordinate checking, manual comparison, or map browsing in a project.

If your target is a clearly defined coordinate point, Locate is usually more direct than POI Search.

2. How to Open Locate

Click Locate in the iXGIS toolbar to open the Coordinate Locate window.

When it opens, the system uses the current map center as the initial reference position and automatically displays that position's coordinates and address information. This is useful because:

• You can immediately see the approximate address of the current map center.
• If you only need to adjust the current location slightly, you do not have to start from an empty form.
• You can use the current map center as the starting point for a new locate operation.

3. Supported Coordinate Input Methods

Locate currently supports two input formats:

• Decimal degrees
• Degrees, minutes, and seconds

1. Decimal Degrees

This is the most common input method. Enter longitude and latitude as decimal degree values, for example:

• Longitude: 116.37304
• Latitude: 39.92594

This format is suitable for:

• Coordinates copied directly from GPS devices, web maps, or third-party platforms
• Manual checks of standard longitude and latitude values in batch records
• Daily positioning and quick comparison

2. Degrees, Minutes, and Seconds

If your source material uses traditional degrees, minutes, and seconds, you can switch to that input mode, for example:

• 116° 22′ 22.94″
• 39° 55′ 33.38″

This format is common in:

• Field record sheets
• Paper survey materials
• Traditional surveying or investigation results

In iXGIS, these two formats can be converted to each other. You do not need to convert them manually; just choose the correct input method.

For coordinate input within China, longitude is generally east longitude and latitude is generally north latitude, so both values are usually positive.

4. Pick a Point on the Map Instead of Typing

In addition to the input boxes, the Locate window provides a map pick button. After enabling it, you can click a position on the map and fill that point's coordinates back into the Locate window.

This is useful when:

• You want to roughly choose a position on the map first, then view its precise coordinates.
• You need to check the center point of a known feature or an intersection.
• You want to obtain coordinates through map interaction instead of manual entry.

Note that clicking a point on the map mainly fills in the coordinates. If you want the map to formally jump to the point and refresh the address information, click the Locate button after picking the point.

5. What Happens After You Click Locate

After you finish entering coordinates and click Locate, the system performs these actions:

1. Converts the entered longitude and latitude to the position required by the current map display.
2. Places a locate marker at the target position.
3. Pans the map view to that position.
4. Queries the corresponding address information and displays it next to the marker.

This means Locate does more than move the map. It also tells you roughly where the point is.

From a user experience perspective, this matters for GIS users because a pair of longitude and latitude values is not intuitive on its own. A combination of coordinates and an address description is easier to judge and communicate.

6. Where the Address Information Comes From

The address description in Locate uses the Tianditu reverse geocoding service.

Reverse geocoding can be understood as looking up an address from coordinates. The input is longitude and latitude, and the output is structured address information. According to the Tianditu reverse geocoding service, returned content usually includes:

• Detailed address
• City or district/county
• Nearest road
• Nearest POI
• Direction and distance relative to nearby roads or POIs

In the current Locate feature in iXGIS, users most directly see the address name corresponding to the locate point. This address usually prefers a more complete address description; if the complete address is not clear enough, a shorter location description may be shown.

This feature can therefore tell you where the point is and help you decide whether it is the position you intended to find.

7. How to Interpret Locate Results

When using locate results, treat them as "coordinate position plus address reference", not as an absolutely unique official street address.

This is because reverse geocoding is essentially semantic matching based on the environment around a coordinate. It may return:

• The nearest road name instead of a specific building name
• A relative position near a POI
• Slightly different address wording in the same area because datasets are updated at different times

For GIS work, a better way to use the result is:

• Use the coordinate position as the primary reference.
• Use the address text as supporting context.
• If an exact street address is required in a formal deliverable, verify it manually.

8. Common Uses

1. Check Field Points

When you receive field sampling points, monitoring points, or inspection point coordinates, you can enter or paste them one by one to quickly check whether they fall in the correct area.

2. Verify Issue Locations

For complaint points, disaster points, anomaly points, or facility issue points with known longitude and latitude, you can locate them first, inspect their surroundings, then judge the situation with basemaps and thematic layers.

3. Support Communication and Reporting

Many non-GIS users are not sensitive to longitude and latitude, but they understand addresses. Displaying the address through Locate makes communication with business users, field staff, or managers easier.

4. Start Further Editing or Analysis

After the map is positioned at the target point, you can continue zooming, take screenshots, measure, overlay thematic layers, or perform further spatial judgment.

9. Things to Watch For

1. The Input Is Longitude and Latitude, Not Projected Coordinates

The values in the Locate window are longitude and latitude in degrees, not projected planar coordinates in meters. Do not paste X and Y values from a projected coordinate system directly into the window.

If your data is in projected coordinates, convert it to longitude and latitude before using Locate.

2. Check Signs for Coordinates Outside China

Within China, most longitude and latitude values are positive. For west longitude or south latitude, pay special attention to the positive and negative signs.

3. Address Information Is Mainly for Supporting Judgment

Reverse geocoding returns an address description. It is not the same as a legally confirmed address. For formal reporting, database entry, or fine-grained management, manual verification is still recommended.

4. Map Picking Is Better for Rough Positioning

If you only click a position on the map with the mouse, accuracy is affected by the current scale and click position. For high-precision coordinate checks, enter accurate coordinate values directly.

10. Recommended Workflow

For daily work, use Locate in this order:

1. Open the project and basemap.
2. Click Locate and check the current map center.
3. Choose Decimal Degrees or Degrees, Minutes, and Seconds.
4. Enter coordinates, or pick a point on the map first.
5. Click Locate.
6. Use the map marker and address information to judge whether the location is correct.
7. If needed, continue zooming, take screenshots, or perform further analysis.

11. Summary

The Locate feature in iXGIS is a coordinate positioning tool designed for practical GIS work. It combines coordinate input, map navigation, and address display so users can place a point on the map quickly and understand its approximate spatial meaning through reverse geocoding results.

In short, its core value is:

• Use coordinates to find a location accurately.
• Use addresses to help read the location.

For coordinate checks, field point organization, issue point review, and map browsing, this is a very useful basic feature.