1. Why it matters in rescue
The people who most need rescue are often the ones who cannot call for help. They may be unconscious from smoke or trapped under a fallen ceiling. They may be too young to answer or hiding silently in a closet. A primary search in heavy smoke is slow. Every room a crew enters is a room it is not searching somewhere else.
Through wall sensing gives the crew a read of each room before anyone goes in. Is someone there? Are they moving? Are they breathing when conditions allow? How many are there and how sure is the read? On a rescue scene its job is simple. It helps decide which room to search first.
The one rule: through wall sensing directs a search and never replaces one. Crews still search every room. A room that cannot be read is always searched by hand.
2. Where it helps
It is built for structures that are standing but unsafe, full of smoke or hiding people who cannot answer. The through wall sensing for search and rescue page walks through each scenario.
- Structure fire. Smoke and darkness do not block a reading. Know which rooms show someone before the primary search reaches them. Know whether a still occupant is breathing when conditions allow.
- Partial collapse. Find voids where someone may still be alive after an earthquake, explosion or structural failure. See which parts of the structure cannot be read.
- Storm damage. After a tornado or hurricane people shelter in closets, bathrooms and interior hallways. Reading the interior rooms first helps crews sweep a damaged street faster.
- Welfare checks. A person down behind a locked door. Know before forcing entry whether someone is there and whether they are breathing when conditions allow.
3. Reading a room
Every room lands in one of four states. Each one tells the crew what to do next.
Someone is there with high confidence.
What to doSearch here first.
Probably someone but the evidence is weak.
What to doTreat as occupied.
No one detected with high confidence.
What to doLower priority and still searched.
The room cannot be read.
What to doSearch by hand.
A no read is never a clear. It means the room could not be read. It does not mean the room is empty. A false clear sends a crew past a room with someone in it. So Vantage is tuned to report no read long before it would risk a false clear. The guide to presence of life detection explains why.
4. Where it fits in the search plan
On Vantage a read follows the same order as the search itself.
- Read the building first. Every room is read from outside before anyone goes in.
- Give every room a state. Occupied, clear, low confidence or no read. Unknown is never shown as clear.
- Rank the rooms. A still occupant goes first. A room that returns no read goes on the plan to be searched by hand.
- Check for breathing when conditions allow. A still person with a breathing rate tells the crew to expect a live patient.
- Keep reading while crews work. Readings update as the search moves through the structure. Counts are shown as honest ranges.
- Hand off to command and EMS. They learn how many patients to expect. Every reading is logged with the time and sealed for the review after the incident.
Each company gets something from the same read. Engine crews start primary search where someone is and not where the hallway leads. Truck companies ladder the rooms that show someone inside. EMS knows how many patients to expect. Incident command sees every room on one screen.
There are two things it will not do. It will not tell you who someone is and it will not show you a picture of the room. Vantage reports presence, movement and a count. It reports breathing when conditions allow. It never reports identity and never captures images or audio. The through wall detection capabilities page covers each answer.
5. What limits it on a rescue scene
Rescue scenes are hard places to read. These are the conditions that lower confidence most and what to do about each one.
- Dense concrete, steel and deep debris return no read. Those areas stay on the search plan and are searched by hand.
- Below grade and flooded spaces may not resolve. Basements and flooded rooms stay on the manual search plan.
- Heavy movement nearby lowers confidence. Machinery, fans, moving water, active collapse and other crews all do it. Pause nearby movement when you can.
- A still and silent person needs time and calm conditions before breathing can be confirmed. Wait for the confirm or treat the room as occupied.
- Large animals can read as occupants. Treat every reading as a lead and not a conclusion.
- Large open buildings are read room by room and not all at once. Read the rooms that matter most first.
The full list is on the limits of through wall sensing page.
6. Authority and records on a rescue
Rescue cannot wait for paperwork and it does not have to. In the United States looking inside a home is still governed by the Fourth Amendment. The Supreme Court has held that responders may enter without a warrant when they reasonably believe someone inside is seriously injured or about to be. Other countries set their own rules.
On Vantage a rescue session opens on an emergency basis in moments. The incident commander is named and the reason is recorded. The supervisor on duty is notified immediately every time. The record is sealed when the session closes and a supervisor reviews it afterward. Welfare checks follow the same path when someone may need immediate aid.
The emergency basis and sealed records sections of the governance model explain each step. Whether a basis applies in a given case is for your department and its counsel to decide. This guide is not legal advice.
7. Training and evaluation
Results from a lab do not tell you how a system behaves in your buildings. An evaluation worth trusting runs where your crews work. It uses ground truth your team controls and it reports every miss.
- Training sessions run on your own facilities under a training basis with people who have agreed to take part. They are kept apart from operational records.
- In a Vantage pilot your team places role players and the operator does not know where.
- You get how often Vantage was right and how often it said no read. You also get every time it was wrong.
Pilot programs are open to fire departments, urban search and rescue teams and emergency management agencies. See pilot programs for through wall sensing.
8. Public sources
The descriptions below are our own short summaries. Read the originals for the full picture.
- Through-the-Wall Sensors for Law Enforcement: Market Survey. National Institute of Justice (2012). NCJ 240729. Among the first uses it names are firefighters checking burning buildings for trapped people. It also names rescue teams finding survivors after a collapse.
- Detection of Presence of Life (DePLife) Prototype Operational Field Assessment Report. DHS Science and Technology Directorate (2023). Firefighters and police officers tested a prototype in the field. Above all they asked for better detection of people who are not moving and for fewer false detections. The report covers a different product. We cite it for what responders said they need.
- Brigham City v. Stuart, 547 U.S. 398 (2006). The Supreme Court decision on entering a home without a warrant to help someone seriously injured or in danger.
