Pass sky chart
get_pass_chartRead-onlyIdempotent
Render a polar sky chart (PNG) of a satellite's pass over a location: where to look, with the moon, planets and stars in their real positions. Returns JSON (the charted pass as a full pass row, the same as find_passes gives, and a one-line summary) and the image. A geostationary satellite has no passes: the result gives stationary (where to point) instead. By default it charts the next pass; give time (the rise or peak of a pass from find_passes or best_pass) to chart that pass instead. Use the same minElevation as the pass came from. A time more than 30 days from the orbital elements' epoch is refused.
Tool call template
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"satellite": "<satellite>"
},
"name": "get_pass_chart"
}
}Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| lat | No | observer latitude in decimal degrees, north positive (-90 to 90). Give it with lon, or give location instead. | |
| lon | No | observer longitude in decimal degrees, east positive and west negative (-180 to 180). | |
| mode | No | "visual" (default): naked-eye passes, sunlit while the sky is dark; "radio": every line-of-sight pass, day or night. | |
| time | No | charts the pass around this time (a pass's rise or peak from find_passes or best_pass). Default: the next pass from now. ISO 8601 with Z or an offset, e.g. "2026-11-14T21:00:00-06:00"; a time with no offset, e.g. "2026-11-14T21:00", is read in the observer's time zone, and the result echoes how it was read (interpretedAs). A local time the clocks skip at a daylight-saving change is moved forward, with a note. | |
| minElev | No | old name for minElevation; still accepted. | |
| skyType | No | how dark the observer's sky is, for the visual rating as on seeksat.com: "city" (stars to magnitude 3.5), "suburban" (stars to magnitude 4.5), "rural" (stars to magnitude 5.5), "dark" (stars to magnitude 6.5). Default "suburban". | |
| location | No | where the observer is, when lat and lon are not given (they win when both are): a Maidenhead grid square (EN52, EN52ve, EN52ve12), coordinates in any common form ("41.88, -87.63", "41.88N 87.63W", "41°52'48"N 87°37'48"W", a Google Maps link or geo: URI), all read locally, or a place name (city, address, landmark) looked up with OpenStreetMap. Prefer lat and lon, or a grid square, when you have them: a place name is a network lookup. | |
| passTime | No | old name for time; still accepted. | |
| satellite | Yes | NORAD catalog number (as a number or a string) or a name, e.g. 25544, "25544" or "iss". | |
| windowHours | No | how far ahead to look, in hours, up to 240 (10 days). Default 72. Only used to find the next pass when no time is given. | |
| minElevation | No | lowest elevation that counts: a pass must climb above it, and rise and set are when it crosses it, in degrees above the horizon (0 to 90). Default 10. | |
| minElevationDeg | No | old name for minElevation; still accepted. |