Writing GPS and Cyber Events

GPS events change the global positioning environment. Cyber events alter selected packet user data. Both require more validation than a direct Spacecraft component event.

Adding a GPS spoofing region

{
  "Enabled": true,
  "Name": "Spoof San Francisco",
  "Time": 600.0,
  "Repeat": false,
  "Type": "GPS",
  "Data": {
    "Type": "Spoofing",
    "Enabled": true,
    "Origin Latitude": 37.7749,
    "Origin Longitude": -122.4194,
    "Origin Altitude": 500000.0,
    "Radius": 50000.0,
    "Spoof Latitude": -37.7749,
    "Spoof Longitude": 122.4194,
    "Spoof Altitude": 20000.0
  }
}

Disable the region later with another GPS event:

{
  "Enabled": true,
  "Name": "Spoofing Off",
  "Time": 1800.0,
  "Repeat": false,
  "Type": "GPS",
  "Data": {
    "Type": "Spoofing",
    "Enabled": false
  }
}

GPS events operate on the global GPS subsystem. Ordinary spacecraft Assets and Target values are not used in the same way as a Spacecraft event.

Adding GPS jamming

Use the GPS presets in Studio for the installed jamming schema. A jamming event normally specifies:

• action such as add, update, or remove
• location and effective radiated power
• optional beam or boresight values
• a stable jammer index used by later update or remove events

Pair every temporary jamming event with a tested recovery or removal event.

Adding a Cyber event

{
  "Enabled": true,
  "Name": "Ping ASCII Overlay",
  "Time": 100.0,
  "Repeat": false,
  "Type": "Cyber",
  "Target": "Spacecraft",
  "Assets": [],
  "Data": {
    "APID": 100,
    "Offset Bytes": 0,
    "Payload": "HELLO",
    "Encoding": "ascii",
    "Expiry Seconds": 120.0,
    "Clear On Reset": true
  }
}

Field	Purpose
APID	Application process identifier to modify
SubType	Optional subtype filter
Offset Bytes	Offset from the beginning of user data
Payload	Replacement byte source
Encoding	ascii, utf8, hex, or base64
Expiry Seconds	Duration; 0 means no expiry
Clear On Reset	Removes the overlay on reset

Cyber event APIDs must match the packet type actually produced by the scenario. Test the unmodified packet first.

Safety and validation

• use a small test scenario
• keep event times early during development
• verify add and removal behavior
• confirm reset clears temporary effects
• confirm questions do not expose the answer before the event
• inspect packet and GPS telemetry, not only Admin history

WARNING

A syntactically valid GPS or Cyber event can still be operationally wrong. Wrong units, APIDs, offsets, or removal indices can produce no effect or modify the wrong data.

Next, score the simulation state with objectives.