# Track curve (dialog)

The “Track curve” dialog is used to display spatial offsets of the source frames as a function of time. This curve is used to check the precision of a telescope mount. The offsets are relative to the reference frame, they are computed separately in X and Y direction.

## Activating the dialog

The dialog can be activated:

1. from the main menu: Plot ‣ Track curve.

## Track curve dialog

Track curve dialog

(1) The actual data set is shown here.

(2) You can switch the labels on the X axis between Julian date (JD) or date and time (UTC).

(3) The list of available data sets is displayed here.

## Data sets

The following data sets are available:

- OFFSETX - The horizontal offset of the frame w.r.t. the reference frame or the catalogue file; in pixels

- OFFSETY - The vertical offset of the frame w.r.t. the reference frame or the catalogue file; in pixels

## Context menu

You can select an individual point by a right click, you can also select more than one point by pressing a Shift key and left mouse button and drawing a rectangle in the graph. Then, click the right mouse button on a point in the selection to open the context menu. It provides following functions:

- Show frame - it shows a preview to a selected frame. It is not allowed when more than one frame is selected.

- Show properties - it opens a new dialog with properties of selected frame. It is not allowed when more than one frame is selected.

- Delete from data set - selected measurements are removed from the current curve, the data will be shown again when you make a new curve or Rebuild the actual curve.

- Remove from project - source frames corresponding to the selected measurements are removed permanently from the list of input files and such measurements won’t be included in any other output. It is not allowed to remove a reference frame.

## Statistics

The Statistics is a tool that computes and shows the minimum, maximum, sample mean and standard deviation.

To activate the tool:

1. From the local menu, select Tools ‣ Statistics. A new panel on the right side of the preview window appears.

If no points are selected, all points in the data set are included in the computation. To restrict the data for the statistics, press and hold the Shift key and draw a rectangle in a graph while you keep the left mouse button pressed down.

## Measurement

The Measurement tool displays two cursors in the graph. The cursors can be adjusted by dragging them using the left mouse button. The position of each cursor, their distance and statistics for the data between cursors is presented.

To activate the tool:

1. From the local menu, select Tools ‣ Measurement. A new panel on the right side of the preview window appears.

   Measurement tool

(1) Choose the axis you want to measure.

(2) Positions of the cursor 1 and 2 are displayed here.

(3) Distance between cursor 1 and 2.

(4) When cursors are defined on the independent (X) axis, number of points (frames) between cursor 1 and 2 are displayed and also minimum, maximum, mean value and sample deviation are presented.

See also

Light curve (dialog)