SimTX API/Packets/CoverageMapResponse

CoverageMapResponse

Frame	ServerFrame, field 35
Member	coverage_map
Direction	Server → client
Session	Control
Roles	ROLE_CONTROL.
Permission	None
Answered by
Answers	CoverageMapRequest
Defined in	control.proto

CoverageMapResponse returns the predicted received power of a CoverageMapRequest as a global raster. Failures arrive as Error with the request's request_id; the v24 available and message fields are gone.

Definition

message CoverageMapResponse {
  reserved 2, 3;
  reserved "available", "message";
  int64 request_id = 1;
  int64 sim_time_ms = 4;
  int32 width = 5;
  int32 height = 6;
  repeated float received_power_dbm = 7;
}

Fields

#	Field	Type	Description
1	request_id	int64	The request this answers.
4	sim_time_ms	int64	Simulated time the prediction is for, Unix ms.
5	width	int32	Raster columns.
6	height	int32	Raster rows.
7	received_power_dbm	repeated float	width × height values of predicted received power in dBm, row-major from the north-west corner. Always finite; −200 dBm means no path.

Reserved, never reused: field numbers 2, 3 and the names available, message.

Raster layout

The raster covers the whole globe. Values are row-major (index = row × width + column). Row 0 is the northernmost; columns run west to east from 180° W. Each value is taken at the centre of its cell:

latitude  =   90 − (row    + 0.5) × 180 / height
longitude = −180 + (column + 0.5) × 360 / width

What the values mean

Each value is the power a reference receiver in that cell would see from the requested transmitter at sim_time_ms. The reference receiver is a resonant half-wave dipole 10 m above ground, broadside to the transmitter (orientation rounded to 15°), without feed line loss. Values come from an analytic skywave model (E and F2 modes) plus ground wave and tropospheric paths, corrected towards ray-traced anchor points where a skywave was traced. Cells without a usable path are −200 dBm. Every value is finite.

See also

• CoverageMapRequest