Attitude Visualization

Documentation Index

Fetch the complete documentation index at: https://docs.valar.space/llms.txt

Use this file to discover all available pages before exploring further.

For the complete documentation index, see llms.txt.

VALAR exposes spacecraft attitude through two complementary plots:

• A quaternion time series on the dedicated Quaternions tab, showing the four quaternion components over a chosen time window.
• A roll / pitch / yaw Euler-angle plot on the Modes tab, embedded alongside the mode schedule.

Both plots are driven by the same underlying attitude profile — the orientation your spacecraft holds under its active mode and any scheduled transitions. This page explains how to read each one. For attitude concepts (modes, body axes, targets), see Attitude modes overview.

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Quaternion plots on the Quaternions tab

Open the Quaternions tab from the sidebar at Attitude → Quaternions, then pick a spacecraft from the spacecraft selector at the top. The page renders four stacked charts, one for each quaternion component:

• Q1, Q2, Q3 — the three vector components of the unit quaternion.
• Q4 (scalar) — the scalar (real) component of the unit quaternion.

A quaternion is a four-number description of a rotation. The four values are dimensionless and always lie between -1 and 1, so every chart shares the same fixed y-axis. The x-axis is time, labelled with the UTC date.

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Adjusting the time window

The time-range pill at the top of the page controls how much history and forecast appear on each chart. The default is 24 h — twelve hours of past attitude and twelve hours of forecast around the current moment. You can switch to 12 h for a tighter view or 72 h for a longer one. If no attitude data is available for the selected window, the charts render blank with no points.

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Reading discontinuities

The quaternion q and its negation -q represent the same physical rotation, so the same attitude can be written in two equivalent ways. When the underlying samples flip sign between consecutive points, the chart draws a brief gap instead of an artificial jump from +0.9 to -0.9. Gaps therefore mark sign transitions in the data, not gaps in coverage. Sign flips most often appear at mode-transition boundaries, because the active and the scheduled modes may produce quaternions with opposite signs even though they describe smoothly continuous orientations.

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What the plotted data reflects

The plotted quaternions reflect your spacecraft’s full attitude schedule:

• When no transition is active, the plot follows the spacecraft’s default attitude mode.
• When a scheduled transition is active, the plot follows the scheduled mode for the duration of its window.
• After a transition ends, the plot returns to the default mode until the next transition.

You do not need to overlay the transition schedule manually — it is already baked into the curve.

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Euler angle plot on the Modes tab

For an operator-friendly view of the same attitude, open Attitude → Modes. The right side of the modes page shows a Roll / Pitch / Yaw chart that expresses the same attitude as three rotation angles instead of four quaternion components.

• Roll, Pitch, Yaw are the rotation angles around the spacecraft’s body axes, applied in the ZYX (3-2-1) sequence.
• Values are in degrees and range from -180 to 180.

The roll / pitch / yaw values are derived from the same underlying attitude profile as the quaternion charts. They are not a new piece of data — just a more human-readable presentation of the same orientation.

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Reference frame

The chart subtitle reads Body w.r.t. <frame> (ZYX / 3-2-1). The frame name identifies the reference the rotation is expressed against — for example, Sun-aligned local frame, LVLH-CCSDS, or EME2000. The frame depends on the active mode: a Sun-pointing mode reports angles against a Sun-aligned frame; an inertial mode reports against an inertial frame. For definitions of each frame, see Reference frames.

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Empty and unavailable states

Two situations prevent the plots from rendering with data:

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No state vector

If the spacecraft has no state vector, the entire Attitude section shows a No state vector available message with an Add a state vector button that takes you to the State Vectors page. Attitude cannot be computed without orbital state, so neither the Quaternions tab nor the Modes tab will render their charts until you add a state vector.

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No attitude configuration

If the spacecraft has a state vector but no default attitude mode has been set, the Quaternions tab shows a Configure modes prompt that links to the Modes tab. The Modes tab in turn lets you pick a default mode and start scheduling transitions — see Attitude modes overview.

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