How is an observation point or epoch-based point taken?

To take an observation point or epoch-based point in tcpGPS, the process consists of performing multiple position captures over a specified time to calculate a precise average.

The steps to configure and perform this measurement are detailed below:

1. Prior Configuration

Before starting the survey, you must set the parameters in the Configuration menu:

• Observation Time: Define the time in seconds during which the receiver will take data (epochs) for that point.

• Long press for points with precision:

  • If this option is enabled, the epoch-based point will only be taken by performing a long press on the point capture button.

  • If it is disabled (and the time is greater than 0), a tap on the point capture button will be sufficient to start the process. This is useful if you only wish to work with observation points.

2. Taking the point

Once on the Survey screen:

1. Press the point capture button (according to the chosen short or long press configuration).

2. The application will begin to take as many captures as possible during the established time.

3. Upon completion, a dialog will appear with the list of captured epochs, showing for each its coordinates (X, Y, Z) and its precisions (Pre.H, Pre.V, PDOP).

3. Review and validation of epochs

In the results dialog, you can manage the measurements before saving them:

• Manual filtering: You can tap specific epochs and press the delete button to remove them if you consider them erroneous.

• Tolerance control: If any epoch exceeds the configured limits, the application will warn you. You can use the "Delete out-of-tolerance epochs" button to automatically clean the list.

• Final Result: The application displays the average of all valid epochs, the standard deviations, and the least favorable value.

4. Completion

If the averaged data is acceptable, press the Save button to store the point in the project.

This method can also be applied during setting out lines following identical logic, allowing you to verify the final position with high precision by taking epochs.