Off-nadir Opportunities

For the complete documentation index, see llms.txt.

An off-nadir opportunity is an overflight opportunity a payload reaches only by slewing away from nadir — straight down — rather than testing access with the payload pointed only directly overhead. Switch it on for an area of interest to see every opportunity the payload’s declared off-nadir pointing limits allow, each carrying a geometric assessment of its own. Route: The Include off-nadir opportunities switch is in the Edit AOI dialog, opened via the pencil icon in the identity hero on the AOI Overview page (the reading it adds appears in the events surface on both AOI Overview and Overflight Events).

This reading is geometric only. A bounded or caveated assessment means that, purely as a matter of geometry, the area of interest falls within the payload’s recorded pointing limits during the stretch of time reported. It is not a statement that the spacecraft can be commanded to point there, nor that it would be free to do so. Agility, attitude, power, thermal, and scheduling feasibility are all real constraints this reading does not model. VALAR states it on screen exactly this way: “This is a geometric bound on the look angle only. It does not account for agility, attitude, power, thermal or scheduling feasibility.”

Turning It On

The Include off-nadir opportunities switch is set per area of interest, under Status & validity in the Edit AOI dialog. Off by default. Turning it on recomputes that area of interest’s overflight forecast, adding every opportunity the payload can be pointed at — not only those directly overhead. With the switch off, the events surface is exactly what it is everywhere else in the product: no off-nadir reading, no Access control, and nothing to opt back out of. Once it’s on, Filtering by Access narrows the list to All, Nadir, or Off-nadir only — choosing Nadir reproduces the list exactly as it stood before you switched this on.

The Assessment

Selected opportunity's detail panel, showing the Off-nadir block with its assessment and disclaimer above the Entry, Peak, Exit, Duration, Payload, Off-boresight, and Blinding rows

Every off-nadir opportunity carries a one-word assessment on the remediability axis — not how good the opportunity is, but what, if anything, you can do about the bound:

Assessment	What it means	What you can do
Bounded	The geometry is clean. Nothing narrows or blocks the bound.	Nothing — there is nothing to chase.
Caveated	Something irreducible narrows the bound. Read the reason.	No action removes it — it is a property of the geometry itself, not a gap in the data.
Not assessable	Something fixable stopped the bound from being placed at all.	Read the reason — it names the missing thing, so you can tell whether the fix is yours (supply the payload’s pointing limits) or Valar’s (classify those limits for release, or refresh the orbit).

The assessment reports validity and provenance only. It never reports how good the opportunity is for imaging, and it is never a verdict on whether the spacecraft can be tasked to point there — see the disclaimer above. Neither the caveated nor the not assessable glyph carries any colour or emphasis, and neither uses a warning or error style — deliberately so. A red or amber treatment would read as “cleared to task” or “do not task,” a judgement this reading never makes.

Vocabulary

Term	Meaning
Nadir	Straight down from the spacecraft to the ground — the payload’s default pointing direction.
Off-nadir (look) angle	How far the payload’s boresight is pointed away from nadir to reach a target.
Slewing	The payload pivoting its boresight away from nadir, toward a target it would otherwise miss.
Along-track / cross-track	The two axes a payload’s off-nadir pointing limits are declared against — along the spacecraft’s direction of travel, and perpendicular to it.
Off-nadir pointing limits (the envelope)	The payload’s declared maximum slew in each direction — the bound this reading tests opportunities against.
Qualifying interval	A contiguous stretch of time, within an opportunity, during which the area of interest genuinely falls inside the payload’s enlarged (off-nadir) field of view.
Envelope window	The outer span from the earliest to the latest qualifying interval — the widest bracket the opportunity could qualify within.
Time within limits	The total duration actually inside the payload’s pointing limits — the sum of the qualifying intervals, deliberately not the width of the envelope window, because that would count the gaps.
Nadir vs. off-nadir-only opportunity	A nadir opportunity is one the payload can access without slewing at all. An off-nadir-only opportunity exists solely because the payload can be pointed off-nadir — it has no straight-down window of its own.
Declared slew axes	Which axis, if any, an opportunity’s off-nadir assessment relied on the payload’s declared pointing limits for. Reads Along-track, Cross-track, Along-track · Cross-track (both, in that fixed order), or None — depending on which of the payload’s declared pointing limits independently shaped the bound. Both axes are now checked independently, so either can be named alone or together.

States You Might See

Alongside the assessment, an off-nadir opportunity can land in one of several states. Each names what to chase — never a generic failure:

State	What it means	What to chase
Pointing limits on file, not yet cleared for release	The payload’s off-nadir pointing limits exist but haven’t been classified for release yet. The envelope window, the qualifying intervals, and every timing on this opportunity are withheld entirely — never shown coarsened.	Valar — get the limits classified for release.
Orbit too old to place the bound	The orbit this opportunity was assessed against is too old to place a trustworthy bound.	Refresh the orbit — a fresher state vector resolves it.
Predates off-nadir assessment	The opportunity was computed before off-nadir access existed for this area of interest. Its other values are unchanged — nothing about it has regressed.	Nothing to chase on the opportunity itself — recompute the area of interest to bring it current.
Composition not yet supported for this payload’s aperture shape	Composition isn’t available for this payload’s shape yet. The payload’s declared pointing limits use a non-isotropic aperture (rectangular, elliptical, or polygon with unequal extents), and composing its two axes into one slew envelope isn’t supported for that shape yet.	Nothing today — this is a capability gap, not missing or misclassified data. The payload’s off-nadir limits are still saved; only the automatic envelope mint is deferred until Valar extends composition support to this aperture shape.

A GSD reading that falls outside its validated domain at this look angle is a related but separate state, documented under Availability states on the Overflight Events page.

Overflight events — the full opportunity list, the per-event detail panel, and the Off-nadir group’s field-by-field reading.
Areas of Interest overview — the page hosting the Edit AOI dialog where the switch lives.
State vectors — refresh an orbit that is too old to place the bound.

Spacecraft Management

Orbit Analysis

Measurements

Ephemeris Generation

Maneuver Operations

Security & Access

STM

Areas of Interest

Automation

Attitude

Passes

Turning It On

The Assessment

Vocabulary

States You Might See

​Turning It On

​The Assessment

​Vocabulary

​States You Might See

​Related Pages

Turning It On

The Assessment

Vocabulary

States You Might See

Related Pages