{
  "$type": "site.standard.document",
  "description": "A system comprises a radar altimeter producing range-to-ground measurements; an aided INS or AHRS producing vertical acceleration, roll, and pitch measurements; an air data system producing barometric altitude measurements; and a processor including a BIV hybrid filter, and a RAIV hybrid filter…",
  "path": "/patents/1374422",
  "publishedAt": "2026-06-02T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01C21/1652",
    "Honeywell International s.r.o."
  ],
  "textContent": "A system comprises a radar altimeter producing range-to-ground measurements; an aided INS or AHRS producing vertical acceleration, roll, and pitch measurements; an air data system producing barometric altitude measurements; and a processor including a BIV hybrid filter, and a RAIV hybrid filter set. The BIV hybrid filter receives the vertical acceleration measurements and barometric altitude measurements. The RAIV hybrid filter set receives input measurements comprising the vertical acceleration, roll, and pitch measurements, BIV hybrid filter statistics, and the range-to-ground measurements. The RAIV hybrid filter set comprises a plurality of hybrid filters that operate in parallel with each other in respective filter slots. A hybrid filter in each filter slot operates on partially overlapping, time limited staggered intervals of the input measurements, with respect to other hybrid filters in other filter slots. Estimated vertical navigation statistics are computed based on input statistics processed in the filter slots.",
  "title": "Radar inertial vertical hybrid filter scheme resistant to terrain variations"
}