SimTX API/Packets/PassPredictionResponse

PassPredictionResponse

Frame	ServerFrame, field 41
Member	passes
Direction	Server → client
Session	Control
Roles	ROLE_CONTROL.
Permission	None
Answered by
Answers	PassPredictionRequest
Defined in	control.proto

PassPredictionResponse lists the passes found for a PassPredictionRequest. Failures arrive as Error.

Definition

message PassPredictionResponse {
  reserved 4;
  reserved "error";
  int64 request_id = 1;
  bytes satellite_id = 2;
  repeated Pass passes = 3;
}

Fields

#	Field	Type	Description
1	request_id	int64	The request this answers.
2	satellite_id	bytes	The satellite.
3	passes	repeated Pass	Passes in time order. Passes that overlap the window are clipped to it.

Field number 4 (formerly error) is reserved and never reused.

Pass

message Pass {
  int64 aos_ms = 1;
  int64 tca_ms = 2;
  int64 los_ms = 3;
  double max_elevation_deg = 4;
  double aos_azimuth_deg = 5;
  double los_azimuth_deg = 6;
  double max_doppler_hz = 7;
}

#	Field	Type	Description
1	aos_ms	int64	Acquisition of signal: elevation rises through the threshold, Unix ms.
2	tca_ms	int64	Time of closest approach (highest elevation), Unix ms.
3	los_ms	int64	Loss of signal, Unix ms.
4	max_elevation_deg	double	Highest elevation, degrees.
5	aos_azimuth_deg	double	Azimuth at AOS, degrees from north through east.
6	los_azimuth_deg	double	Azimuth at LOS, degrees.
7	max_doppler_hz	double	Largest absolute Doppler shift between AOS and LOS at frequency_hz, Hz, ≥ 0. 0 when no frequency was given.

Example

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

pass_response (server to client, 83 bytes):

52                              frame length 82
CA 02 4F                        passes (PassPredictionResponse), 79 bytes
  08 16                         request_id = 22
  12 10 99 99 99 99 …           satellite_id = 99999999-8888-4777-8666-555555555555
  1A 39                         passes (Pass), 57 bytes
    08 C0 98 C0 B9 97 34        aos_ms = 1793001000000
    10 A0 C0 D2 B9 97 34        tca_ms = 1793001300000
    18 80 E8 E4 B9 97 34        los_ms = 1793001600000
    21 00 00 00 00 00 40 4F 40  max_elevation_deg = 62.5
    29 00 00 00 00 00 E0 75 40  aos_azimuth_deg = 350.0
    31 00 00 00 00 00 40 65 40  los_azimuth_deg = 170.0
    39 00 00 00 00 00 24 C3 40  max_doppler_hz = 9800.0

See also

• PassPredictionRequest
• Passes