Clanker: Remove development history and server internals

2026-10-24T17:16:29Z

Remove development history and server internals

← Older revision		Revision as of 17:16, 24 October 2026
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	== Examples ==		== Examples ==
	Complete frames, including the varint length prefix~~, from the protocol's golden test vectors (<code>protocol/simtx/v25/testdata/frames.json</code>)~~.		Complete frames, including the varint length prefix.

	'''<code>pass_request_station_observer</code>''' (client to server, 74 bytes):		'''<code>pass_request_station_observer</code>''' (client to server, 74 bytes):

Clanker: Protocol v25 reference

2026-10-24T16:27:46Z

Protocol v25 reference

New page

{{SimTX API navigation}}
{{SimTX packet
| name = PassPredictionRequest
| frame = ClientFrame
| field = 41
| member = passes
| direction = c2s
| session = [[SimTX API/Control session|Control]]
| roles = <code>ROLE_CONTROL</code>.
| permission = None. The satellite and an observer station must be visible to the session.
| reply = [[SimTX API/Packets/PassPredictionResponse|PassPredictionResponse]] or [[SimTX API/Packets/Error|Error]]
| group = control
| file = control.proto
}}
'''PassPredictionRequest''' asks the server when a satellite will be above an observer's horizon within a time window. It needs the server feature <code>passes</code>. The observer is one of your ground stations (or a PUBLIC one) or an arbitrary position.

== Definition ==
<syntaxhighlight lang="protobuf">
message PassPredictionRequest {
int64 request_id = 1;
bytes satellite_id = 2;
oneof observer_site {
bytes observer_station_id = 3;
GeoPoint observer = 4;
}
int64 from_ms = 5;
int64 to_ms = 6; // at most 7 days after from_ms
double min_elevation_deg = 7;
double frequency_hz = 8; // for max Doppler; 0 = skip
}
</syntaxhighlight>

== Fields ==
{| class="wikitable"
! # !! Field !! Type !! Description
|-
| 1 || <code>request_id</code> || <code>int64</code> || Nonzero; echoed in the [[SimTX API/Packets/PassPredictionResponse|PassPredictionResponse]] or [[SimTX API/Packets/Error|Error]].
|-
| 2 || <code>satellite_id</code> || <code>bytes</code> || 16-byte UUID of the satellite.
|-
| 3 || <code>observer_station_id</code> || <code>bytes</code> || Member of <code>oneof observer_site</code>. A ground station to observe from.
|-
| 4 || <code>observer</code> || [[SimTX API/Data types#GeoPoint|GeoPoint]] || Member of <code>oneof observer_site</code>. An arbitrary observer position.
|-
| 5 || <code>from_ms</code> || <code>int64</code> || Start of the window, Unix ms of simulation time.
|-
| 6 || <code>to_ms</code> || <code>int64</code> || End of the window, Unix ms. At most 7 days after <code>from_ms</code>.
|-
| 7 || <code>min_elevation_deg</code> || <code>double</code> || Elevation threshold for acquisition and loss of signal, degrees.
|-
| 8 || <code>frequency_hz</code> || <code>double</code> || Carrier frequency for <code>max_doppler_hz</code>, Hz. 0 skips the Doppler computation.
|}

== Behaviour ==
* Exactly one of <code>observer_station_id</code> and <code>observer</code>. An observer station must be a ground station that currently has a live session on that server and is PUBLIC or your own; otherwise the request is answered with [[SimTX API/Packets/Error|Error]] <code>NOT_FOUND</code> (<i>Unknown observer station on this server; send the observer location instead</i>).
* The window may be at most 7 days long, between the years 1970 and 2200.
* Elevations are geometric (no refraction), on the 6,371 km sphere. See [[SimTX API/Satellites#Passes|Passes]] for the algorithm.
* Passes that overlap the window are clipped to it, and to a deorbiting satellite's reentry. An always-visible geostationary satellite gives one window-long pass; a never-visible one gives none.
* Satellite failures are answered with [[SimTX API/Packets/Error|Error]] as for [[SimTX API/Packets/EphemerisRequest|EphemerisRequest]].
* Heavy request.

== Examples ==
Complete frames, including the varint length prefix, from the protocol's golden test vectors (<code>protocol/simtx/v25/testdata/frames.json</code>).

'''<code>pass_request_station_observer</code>''' (client to server, 74 bytes):

<syntaxhighlight lang="text">
49 frame length 73
CA 02 46 passes (PassPredictionRequest), 70 bytes
08 16 request_id = 22
12 10 99 99 99 99 … satellite_id = 99999999-8888-4777-8666-555555555555
1A 10 11 11 11 11 … observer_station_id = 11111111-2222-4333-8444-555555555555
28 80 94 83 B9 97 34 from_ms = 1793000000000
30 80 CC 9C E2 97 34 to_ms = 1793086400000
39 00 00 00 00 00 00 24 40 min_elevation_deg = 10.0
41 00 00 00 60 19 EF B9 41 frequency_hz = 435100000.0
</syntaxhighlight>

'''<code>pass_request_point_observer</code>''' (client to server, 67 bytes):

<syntaxhighlight lang="text">
42 frame length 66
CA 02 3F passes (PassPredictionRequest), 63 bytes
08 17 request_id = 23
12 10 99 99 99 99 … satellite_id = 99999999-8888-4777-8666-555555555555
22 1B observer (GeoPoint), 27 bytes
09 00 00 00 00 00 C0 47 40 latitude_deg = 47.5
11 00 00 00 00 00 00 33 40 longitude_deg = 19.0
19 00 00 00 00 00 00 5E 40 altitude_meters = 120.0
28 80 94 83 B9 97 34 from_ms = 1793000000000
30 80 CC 9C E2 97 34 to_ms = 1793086400000
</syntaxhighlight>

== See also ==
* [[SimTX API/Satellites#Passes|Passes]]
* [[SimTX API/Packets/PassPredictionResponse|PassPredictionResponse]]

{{SimTX API navbox}}
[[Category:SimTX API]]

SimTX API/Packets/PassPredictionRequest - Revision history

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