Glossary¶
Words you will see in the product
Product terms as they appear in ASTROLAB. Field-by-field lists live on the asset and analysis pages.
| Term | Meaning |
|---|---|
.astrolab |
Mission file you export or open. Same document on Web and Desktop. |
| 2D Viewer | Scenario tab (Web) or 2D Mission Viewer Settings (Desktop): map imagery, day/night lighting, imagery boost. |
| 3D Viewer | Scenario tab (Web) or 3D Mission Viewer Settings (Desktop): globe lighting, overlays, Sun/Moon display, Earth frame, debug axes. |
| Access | Times when a geometric (and constraint) relationship is true — for example a satellite in view of a station. |
| Activity Log | Message list under the Mission Tree (apply, save, scene, analysis). First place to look when something did not appear. |
| ACQUISITION-LEG wait | Former catalogue name of Look delay. |
| Acquisition | Instant the satellite has the information: first see of the AOI target; bytes enter the MMFU (created_at). Start of Delivery delay. Coverage and latency clocks. |
| Acquisition delay | Generation → Acquisition. The Discrete Coverage clock (and IoT Latency wait). In facility-tasking it is Tasking delay + Look delay. Coverage and latency clocks. |
| Acquirer | Who provides coverage (spacecraft, sensor, or a constellation expanded to members). |
| Active | When off, the asset is skipped in scene refresh and typically in analyses. |
| Analysis | A study item in the tree (Coverage, Link, Power, …). Configure → Apply → Run Analysis → Dashboard / overlays. |
| Antenna | Mounted RF aperture (pattern) on a spacecraft or vehicle. |
| Age of Information | Ground freshness: now − Acquisition of the last delivered chunk. Not Delivery delay. Spell it out — AOI is area of interest. Coverage and latency clocks. |
| AOI | Area of interest — a region on Earth (country, polygon, or global layer such as All Land) used by coverage. |
| Apply Changes | Writes the Properties edit into the mission and updates the scene. Required for General / Environment and assets; not required for 3D / 2D Viewer toggles. |
| Asset | An item in the tree: spacecraft, facility, sensor, analysis, … |
| Attitude | How the spacecraft is oriented (for example nadir). Points sensors, antennas, and arrays. |
| Availability | Coverage: fraction of the interval a cell or Static site is in view. Not session Unattended. Coverage. |
| Battery | Energy storage on a spacecraft (SOC over the scenario). Used by Power analysis. |
| Birth | Former name of Generation. |
| Blind gap | Coverage revisit: time between successive accesses at a cell or Static site. Not Latency Unattended. |
| Central body | Body the mission is referenced to. Analyses use Earth. The 3D camera can instead centre on the Moon. |
| CGR | Contact Graph Routing: per-message earliest-arrival search on a Connection Network contact plan. Used when Coverage or Latency policy is ISL (CGR earliest delivery). Not fewest hops and not min-max delay. ISL routing · standards. |
| CGR-ETO | CGR with radio occupancy. Each radio and each contact keep the intervals already radiating. A later booking does not erase an earlier gap. Caps: Max. Concurrent ISL Links, Max. Concurrent Downlink Links, and Max. Concurrent Uplinks for Static IoT sites. Contact Graph Routing. |
| Chain outcomes | Discrete facility-tasking result: never tasked / tasked-no-image / acquired, usually by origin facility. |
| Clear Scene | Removes graphics from the viewer. The mission document is unchanged. |
| Cloud library | Missions stored on your Web account (Engineering Portal). Counted against plan quota. |
| Command receiver | Spacecraft that may hear a tasking facility, on Direct and on ISL command. It can differ from the acquirer that takes the picture. A sensor acquirer uses its parent bus. |
| Completed | Analysis finished successfully. Generate plots; overlays appear in Design when the study has them. |
| Connection network | Declared links (ground and space). Ends can be buses or laser / dump-antenna sensors. Routing Analysis finds the best route over it; Latency dump and Coverage ISL command walk the parent buses. Sensors as terminals. |
| Constellation | Walker grouping generated from a seed spacecraft. Members stay ordinary spacecraft. |
| Constraint | Extra filter on access (elevation, range, eclipse, illumination, …). |
| Continuous coverage | Coverage mode that paints a grid over the domain (percent covered, gaps, heatmaps). |
| Coverage | How well acquirers serve a region or a set of events: Continuous (grid), Discrete (events), or Static (fixed points). |
| Dashboard | Centre view for plots and report tables. Pick an asset, a template, then Generate. |
| Delivery | Instant bytes arrive at a gateway (delivered_at). End of Delivery delay. Coverage and latency clocks. |
| Delivery delay | Acquisition → Delivery (delivered_at − created_at). Dump to a gateway, including onboard MMFU wait and any ISL hops. Never Generation → Delivery. Former plot name: End-to-end latency. Coverage and latency clocks. |
| Demand event | One Discrete request (born in the AOI, or at a facility then aimed at an AOI point). |
| Design | Centre view for the live 3D / 2D scene (globe, playback, overlays). |
| Dirty * | Unapplied Properties edits (Apply Changes), or a stale analysis (Run Analysis). |
| Discrete coverage | Coverage mode that generates demand events and asks who captures each one (AOI-born imaging, or facility tasking). |
| DTN | Delay-/Disruption-Tolerant Networking. Store-and-forward when contacts are scheduled and episodic. CGR/SABR is the usual routing procedure. Contact Graph Routing. |
| End-to-end latency | Former plot name of Delivery delay. |
| Earth-fixed (ECEF) | 3D view frame: Earth rotates under an Earth-fixed camera. 2D is always this map. |
| Earth inertial (ICRF) | 3D view frame: inertial camera; stars/Earth orientation follow inertial motion. |
| Engineering Portal | Account area (Overview, Missions, plan, preferences). Account in the top bar; Mission returns to Design. |
| Environment | Scenario tab: Sun/Moon ephemeris, optical climate, RF/ITU climate for analyses — not the same as Show Sun/Moon on 3D Viewer. |
| Ephemeris | Position versus time (propagated orbit or an imported file). |
| Event assignment | Discrete Latency: one file per event. Of every spacecraft that can acquire it, only the one CGR would put on the ground earliest makes the file. First acquirer is who saw it first; assigned acquirer is who made the file. Latency. |
| Export | Download the current mission as a .astrolab file. |
| Facility | Ground station (lat/lon/alt), often from the station database. Used for tasking, links, and downlink. |
| Facility tasking | Discrete demand: the request is born at a checked facility. Direct: the same acquirer must see that station first, then the AOI target. ISL command: a command receiver hears the station and CGR forwards the order to the acquirer. |
| Failed | Analysis did not finish. Read Properties or the Activity Log (missing target, empty geometry, or a plan limit). |
| Follow | Right-click a spacecraft marker in 3D to lock the camera and show the model. Untracked spacecraft stay as markers. |
| FOV | Field of view of a sensor. Together with pointing, it shapes the swath on Earth. |
| Generation | Instant a Discrete request or IoT packet is born (t_birth). Not Acquisition. Coverage and latency clocks. |
| Ground elevation | Constraint: minimum elevation angle at a facility (or similar ground geometry). |
| Ground track | Sub-satellite path on Earth over the scenario. |
| Graticule | Meridians and parallels drawn on the globe (3D Viewer overlay). |
| ISL | Inter-satellite link: a spacecraft–spacecraft edge on a Connection Network, or a laser sensor pair that collapses to those buses. ISL (CGR earliest delivery) is the opt-in policy that routes a command (Coverage) or a file (Latency) over those edges. ISL routing. |
| Keplerian | Default propagator: two-body orbit from the initial Keplerian / state elements. |
| Latency | Data-plane study: after Acquisition, Delivery delay to a gateway (MMFU + Connection Network). Default dump is Direct (this bus’s X-band); ISL (CGR) is opt-in. Coverage and latency clocks. |
| Lifetime | Analysis: drag-driven time to re-entry (or similar end-of-life). |
| Link | Pairwise access between two assets, with an optional RF budget. |
| Link budget | RF quality on a link (margin, atmosphere, antennas) — beyond geometry-only access. |
| Look delay | Facility-tasking: Tasking → Acquisition (order onboard the acquirer → information onboard). Same clock if the order arrived over ISL. Former name: ACQUISITION-LEG wait. Coverage and latency clocks. |
| Mission | One ASTROLAB study: scenario + assets + analyses, stored as cloud library and/or .astrolab. |
| Mission Tree | Left-column list of everything in the mission. Select a row to edit it in Properties. |
| MLTAN | Mean local time of the ascending node (hours). Sets the SSO lighting family (for example 6.0 h dawn–dusk, ~10 h morning optical). |
| MMFU | Onboard mass-memory / FIFO on the spacecraft bus. Latency produce writes here; dump drains it; overflow is not delivered. |
| Mounted asset | Sensor, antenna, or similar attached to a parent (spacecraft or vehicle). Add from the parent, not from a global folder. |
| Nadir | Attitude law: spacecraft +Z toward Earth centre (typical Earth-observation starting point). |
| Orbit design wizard | Orbit tab helper (SSO, LEO generic, …) that writes Keplerian / state fields into the document. |
| Pending latency | Age of the oldest byte still in the MMFU (now − that byte’s Acquisition). Coverage and latency clocks. |
| Pickup | Former name of Acquisition. |
| Plan | Web entitlement tier (Trial, Basic, Pro, …). Caps window, step, constellation size, coverage mode, export, … |
| Plan limit | Cap on your Trial or paid plan. ASTROLAB explains the block and how to stay inside or upgrade. |
| Playback | Scene transport: play, reverse, pause, stop (jump to start), speed (1x, 2x, …), and editable UTC. |
| Power | Analysis: generation, loads, and battery SOC over the scenario. |
| Propagator | How the orbit is advanced in time (Keplerian, Eckstein–Hechler, DSST, Numerical). Apply Changes uses that choice on the globe. |
| Properties | Right-column editor for the tree selection. |
| Propulsion | Tank + thruster on a spacecraft (chemical or electrical). Editor and analyses land in later Beta builds. |
| Reachability | Coverage Static (and Continuous simple coverage): site or cell seen at least once, or never. Not a delay clock. Coverage. |
| SABR | Schedule-Aware Bundle Routing: CCSDS Recommended Standard (734.3-B-1) for CGR-style routing on a contact plan. ASTROLAB’s ISL (CGR earliest delivery) follows that objective (earliest projected delivery), not ION on the wire. Contact Graph Routing. |
| Receiver | RF front-end (Simple / Complex), usually with an antenna. |
| Refresh All | Rebuild the whole 3D scene. Prefer Apply Changes on the asset you just edited. |
| ReportGraph | Plot and report templates in Dashboard (and Desktop Report & Graph Manager). |
| Revisit time | Coverage: gap between successive accesses (min / mean / max). Same family as Blind gap. Not Latency Unattended. |
| Routing Analysis | Best route over time from a source to the best of several targets on a connection network (shortest path, fewest hops, fastest file or CGR), with target / relay usage. Does not move traffic — that is Latency / ISL CGR. |
| Run Analysis | Executes the selected study. Tree menu or the button at the bottom of Properties. |
| Save | Write the mission to the cloud library (Web; counts toward quota). |
| Scenario | Mission time window, step, environment, and globe display (3D / 2D Viewer). Root of the Mission Tree. |
| Scenario time step | Sampling interval for dynamics and analyses. Trial / Basic minimum 120 s; Pro 60 s. |
| Seed spacecraft | Bus copied by Create Walker Constellation (orbit, attitude, payloads as inherited). |
| Sensor | Mounted optical (or typed) instrument. Coverage can acquire with the sensor FOV or with spacecraft line-of-sight only. The same asset type on a Connection Network can be a laser or dump antenna: access uses its FOV; Routing / Latency / command ISL walk the parent spacecraft. |
| Sensor swath | Footprint drawn on the globe when Show sensor swath is on. |
| Served | Static session Latency: carried live end to end to a gateway (flow allocation, no MMFU). Opposite of Unattended. Coverage and latency clocks. |
| Service ratio | Static session Latency: served time over the whole interval (served + unattended + no coverage) of one client. |
| Solar array | Power panels on a spacecraft. Used by Power analysis. |
| SSO | Sun-synchronous orbit. Designed from altitude + MLTAN in the orbit wizard. |
| Space object | Catalog / debris population in the scene (visual today; SSA analyses later). Not a mission spacecraft you fly. |
| Spacecraft | Orbital vehicle: orbit, attitude, and parent for payloads. |
| Stale | Previous analysis results no longer match the current mission — run the analysis again. What counts: Stale analyses. |
| Static coverage | Coverage mode: a fixed set of points (count + seed). KPIs are reachability, access, availability, revisit — no delay clocks. Latency then uses those sites as IoT packets or a session. |
| Station keeping | Analysis: LEO/GEO maintenance and Δv. |
| Target | Geographic point asset (not an AOI region). |
| Tasking | Instant the satellite takes the order. Direct: first see of the origin facility. ISL command: the acquirer has the forwarded order. Facility-tasking Discrete only. |
| Tasking delay | Generation → Tasking. Facility-tasking Discrete only. Former name: TASKING wait. Coverage and latency clocks. |
| TASKING wait | Former catalogue name of Tasking delay. |
| Terminator | Day/night boundary on the Earth in 3D and 2D when globe lighting is on. Moves with UTC. |
| TOTAL wait | Former catalogue name of Acquisition delay. |
| Transmitter | RF source (Simple / Complex), usually with an antenna. |
| Trial | Default Web plan after signup (15 days, 24 h scenario, 120 s step, one cloud mission). No card required. |
| UTC | Scene clock (YYYY-MM-DD HH:mm:ss). Edit and press Enter to jump inside the scenario window. |
| Unattended | Static session Latency: in view but not served — no path, or the network is busy. Not Coverage availability / blind gap, and not a packet delay. Coverage and latency clocks. |
| Vehicle | Waypoint / trajectory platform (not an orbiting spacecraft). |
| Wait to pickup | Former IoT plot name of Acquisition delay. |
| Walker constellation | Fleet generated from a seed: N satellites, P planes, phasing F. |
| Walker Delta | Walker pattern with RAAN spread over 360°. |
| Walker Star | Walker pattern with RAAN spread over 180° (polar-style). |