# Sampled Geometric Observing Window - Celestial Visibility

> Sampled Geometric Observing Window - Celestial Visibility is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.100013/call, status unknown (last checked 2026-10-16).

Computes deterministic approximate GMST-based celestial geometry (altitude/visibility) for a set of UTC time samples, an observer site, and frozen equatorial target positions, without refraction or live atmospheric data.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/celestial/observations/sampled-windows?utm_source=zero.xyz
- Price: $0.100013/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sampled-geometric-observing-window-celestial-visibility-8ef66858
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5QKJBrc8EBHOjBaqCI3Cr

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sampled-geometric-observing-window-celestial-visibility-8ef66858 -d '<json body>'
```

Example prompt: Can you check whether my telescope targets at equatorial coordinates RA 10h 45m Dec +14° and RA 22h 30m Dec -5° will be above 15 degrees altitude from my site in Tucson (32.2°N, 110.9°W, 750m elevation) for these 8 UTC timestamps tomorrow night? Use public data class.

## When to prefer this

Choose this endpoint when you need deterministic, reproducible celestial geometry calculations at specific sampled UTC times for a fixed observer site and frozen equatorial target coordinates — especially when atmospheric refraction and live ephemeris accuracy are not required. It is ideal for planning, scheduling, synthetic dataset generation, and software testing where exact repeatability matters more than full precision. Prefer alternatives when you need real-time tracking, refraction-corrected altitudes, or continuous visibility curves.

## Known failure modes

- Too many time samples (>64) or targets (>12) — request rejected with validation error
- Invalid site coordinates or missing required site fields — schema validation failure
- Altitude threshold outside valid range (-90° to +90° in microdegrees) — rejected
- Invalid or missing dataClass enum value — validation error
- Malformed or missing times array — request rejected
- Service unavailability returns 402 or 5xx errors depending on payment/routing layer

## How this service works

Deterministic approximate GMST geometry at supplied UTC samples, site and frozen equatorial positions; no refraction, weather, live data or continuous visibility claims. New modular adapter: retained result recovery for 24 hours, minimal receipt metadata for 90 days. Existing live route unchanged.

## Output

Returns a structured set of sampled celestial geometry results for each (time, target) pair: including approximate altitude and GMST-derived positional geometry. Results are retained for 24 hours; minimal receipt metadata is retained for 90 days. No atmospheric refraction, weather corrections, or live ephemeris data are included.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "site": {
   "type": "object"
  },
  "times": {
   "type": "array",
   "maxItems": 64,
   "minItems": 1
  },
  "targets": {
   "type": "array",
   "maxItems": 12,
   "minItems": 1
  },
  "dataClass": {
   "enum": [
    "public",
    "synthetic"
   ],
   "type": "string"
  },
  "minimumAltitudeMicrodeg": {
   "type": "integer",
   "maximum": 90000000,
   "minimum": -90000000
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sampled-geometric-observing-window-celestial-visibility-8ef66858/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)