How to survey the radio signals in your home or neighbourhood

A good radio-frequency survey isn't one long walk; it's a few short, repeatable ones. This guide is the full method we recommend for anyone surveying a home, a building or a few blocks: how to plan, which settings to fix, how to build a baseline, how to check a surprising reading, and how to keep a record that holds up when you or someone else looks at it later.

What a radio survey actually measures

A survey with Consentiva records the radio spectrum around you as you move. A HackRF One receiver, plugged into an Android phone, steps across the frequency range you choose. At each step it captures a slice of spectrum, runs an FFT (a calculation that turns the raw radio samples into a list of levels at each frequency) and then summarises the result into 1 MHz channels. For each channel it keeps two numbers: the peak (the strongest moment seen) and the channel power (the average energy across that megahertz). One full pass across the range is a sweep, and each sweep is stamped with the time and your GPS position.

So the raw material of a survey is a long list of sweeps, each one a snapshot of "how much radio energy was in each megahertz, here, at this moment". Everything else in this guide is about collecting those snapshots in a way that lets you compare them fairly.

Three limits are worth knowing from the start:

• The levels are relative unless you calibrate. Consentiva reports levels in dBFS (decibels relative to the receiver's full scale) unless you enter a calibration offset, in which case it shows dBm. dBFS readings are consistent from walk to walk with the same kit and settings, which is what a survey needs, but they aren't an absolute power. Our guide to dBm and other RF units explains the difference.
• It shows signals, not who sent them. A survey tells you the frequency and strength of what was present. The frequency points to the kind of service that probably uses it, such as cellular, Wi-Fi or two-way radio, but not to a specific operator or device.
• It isn't an exposure measurement. The receiver, antenna and software aren't a calibrated field-strength meter, and the readings aren't comparable with exposure limits. If that's your question, read RF exposure limits explained, which covers how those limits are set and who measures against them.

If the idea of a spectrum display is new to you, What is a spectrum analyzer? covers the basics in more depth.

Choose your goal: baseline, investigation or documentation

Write down the question before you start. Almost every survey falls into one of three types, and each one calls for a different plan.

The types build on each other. An investigation without a baseline is guesswork, because you have nothing to compare against. Documentation without careful method is just a screenshot. Most people start with a baseline even when they have a specific concern, because the baseline is what makes the concern testable.

Plan the route

A route is the single most important part of a repeatable survey. If you walk a different path each time, every difference in the readings could just be a difference in where you were.

Pick a loop you can repeat exactly

Choose a loop that starts and ends at the same place, ideally your front door. Stick to public pavements. A loop of 1–3 km is a good size: long enough to cover several blocks, short enough to repeat often without it becoming a chore. Consentiva groups the baseline into blocks of about 150 metres, so a 2 km loop covers roughly a dozen blocks.

Walk it in the same direction

Walk the loop the same way round every time, and keep to the same side of each street. The difference between the near and far side of a road can be enough to change readings from a transmitter on one side, especially at higher frequencies where buildings block more of the signal.

Include the places you care about, and some you don't

If your concern is a particular building or corner, make sure the route passes it and also passes ordinary streets of a similar type. Those ordinary streets act as a control: if something odd appears everywhere, it's probably the city, the weather or your kit; if it appears only near one place, that's more interesting.

Note fixed landmarks

Cell sites on rooftops, broadcast masts, a hospital, a police station, a fire station, a marina, a building with a large antenna farm: note them on a paper map or in a mark during your first walk. They explain many strong readings later. Our guide to finding cell towers near you shows how to locate the cell sites along your route.

Plan the times and the days

Radio use changes through the day. Cellular traffic rises during busy hours, two-way radio use follows work shifts, and some services only transmit at certain times. Consentiva keeps a separate baseline for night, morning, afternoon and evening, so a walk at 7 a.m. is compared with other morning walks, not with a busy evening.

• Pick the periods you care about. If a concern is about evenings, your baseline needs several evening walks. Morning walks won't help with that comparison.
• Repeat on different days. Two or three walks per period, on different days, is the minimum for a baseline you can lean on. One walk can't tell a regular signal from a one-off.
• Include a weekend if it matters. Construction crews, delivery fleets and events change the radio picture between weekdays and weekends.
• Keep a rough start time. Starting within about half an hour of the same time each day makes walks easier to compare.

Keep a consistent pace and phone position

The receiver needs a moment to complete each sweep. A wide range takes longer than a narrow one, because the HackRF has to retune more times to cover it. At a steady walking pace you get several sweeps per block on a typical range. Walking much faster thins out the data; stopping for long periods piles up sweeps in one spot.

• Walk at an ordinary, steady pace. If you want more detail somewhere, slow down there on every walk, not just once.
• Hold the antenna the same way. Vertical is a sensible default, because many land-based services use vertical antennas. A single antenna picks up less from signals with the opposite polarisation, so tilting it changes readings.
• Keep the kit in the same place. Carry the HackRF in the same hand, pocket or bag on each walk. Your body absorbs and blocks radio energy, so carrying the antenna on the far side of your body from a transmitter reads lower than carrying it on the near side.
• Keep the screen on. Phones pause web pages when the screen turns off. Consentiva asks the phone to keep the screen awake during a walk; leave it in the foreground.

Equipment checklist

Pack the same kit for every walk. The full setup is covered in our HackRF One and Android setup guide; this is the short list to run through at the door.

Never connect anything that can transmit to the HackRF's antenna port, and never feed it a strong signal directly. Its maximum safe input is low: the maker specifies −5 dBm. Stronger inputs can damage the receiver.

Choose your settings, then don't touch them

Settings decide what the receiver sees and how big each reading looks. Changing them between walks changes every number, which makes the comparison with your baseline meaningless. Pick once, write them down, and keep them.

Frequency range

Your plan affects the choice. The Free plan covers 30 MHz–2.7 GHz with analysis locked and 7-day retention, Standard covers up to 2.7 GHz, and Full covers up to 6 GHz. See the plans for details. If your question involves 5 GHz Wi-Fi or the higher cellular bands, you'll need a range that reaches them. Our guide to 5G frequency bands lists which bands sit where.

A narrower range sweeps faster, which gives more sweeps per block. Choose the narrowest range that still answers your question.

Gain

The HackRF has three gain stages. The LNA (0–40 dB) amplifies the signal at the front of the receiver. The VGA (0–62 dB) amplifies it later in the chain. The RF amp adds a further +14 dB right at the input. More gain lifts weak signals out of the noise but also makes the receiver easier to overload with strong ones.

• Start with the defaults and keep the RF amp off in a city.
• If you see many strange spikes near strong transmitters, lower the LNA gain, and use that lower setting for every walk on that route from then on.
• Write the three gain values in your notes. They are part of the record.

Calibration offset

If you have calibrated your kit against a known signal source, you can enter a calibration offset and Consentiva will show levels in dBm. If you haven't, leave it at zero and work in dBFS. Don't guess an offset; a wrong one is worse than none, because it looks authoritative.

Why fixed settings matter so much

Imagine you raise the LNA gain by 8 dB halfway through the week. Every signal on later walks now reads about 8 dB stronger than on earlier ones. Compared with a baseline built at the old setting, the whole spectrum looks "stronger than usual". Nothing in the air changed; you did. Fixed settings stop that from happening. If you must change something, start a fresh baseline with the new settings rather than mixing the two.

Build a baseline over several walks

The baseline is Consentiva's memory of what is normal for each block and each time period. It is what lets the app say "this is unusual here" rather than just "this is strong".

How the baseline works

Each sweep is assigned to a block of about 150 metres, based on its GPS position, and to one of four time periods: night, morning, afternoon or evening. Over several walks, Consentiva learns the typical level in each 1 MHz channel for each block and period. Later sweeps are compared with that typical level.

When there is no baseline yet for a block and period, the app is in learning mode and shows Learning instead of flagging anything. That isn't a fault. It just means there's nothing to compare against yet.

Step by step

1. Fix your route, range and gain as described above, and write them down.
2. Choose the time periods you need. Start with the one that matters most.
3. Walk the route with Use this walk to learn what's normal switched on, so the walk contributes to the baseline.
4. Repeat on at least two more days in the same period. More walks make the baseline steadier.
5. Repeat for other periods if your question needs them.
6. Check the report. The summary shows the share of sweeps that had a baseline to compare against. When that figure is high for your route, the baseline is in place. Reading a Consentiva report explains each section.

When to switch "learn what's normal" off

A baseline should describe ordinary conditions. If you are walking specifically to look at something you think is unusual, switch the learning option off for that walk. Otherwise the unusual signal becomes part of "normal", and future walks will stop flagging it. The same applies to walks during an obviously unusual event, such as a street festival, a large emergency response or a film crew with radios, unless you want that event in the baseline.

A baseline is never finished

The radio environment changes. Networks add capacity, businesses install new Wi-Fi, a cell site is upgraded. A baseline built in spring may be out of date by autumn. Keep adding ordinary walks from time to time so the baseline follows those slow changes.

Conduct an investigation walk

Once a baseline exists, an investigation walk asks a narrower question: is there something here that isn't normal, and where is it strongest?

1. Use exactly the same settings as the baseline. Check the range and gain before you start.
2. Switch learning off for this walk, so whatever you find doesn't get absorbed into the baseline.
3. Walk the normal route first, at the normal pace. That gives a fair comparison with the baseline for the whole loop.
4. Then make focused passes. Approach the area of interest from at least two directions, pass it, and continue well beyond it. A signal that peaks at one spot from every direction is coming from near that spot.
5. Mark as you go. Use voice marks to note what's around you at the moments that matter (more on this below).
6. Look at the live display, but don't chase it. Note anything striking with a mark, then keep to the plan. The report afterwards shows where each unusual signal peaked, which is more reliable than impressions mid-walk.
7. Review the report the same day while the walk is fresh in your mind.

What "unusual" means

Consentiva flags a signal as Unusual when it is stronger than the baseline for that block and time period. The report gives each one a status: new when there is normally nothing at that frequency there, or elevated when a usual signal is much stronger than normal. Each finding shows its peak frequency, its width, how far above normal it was in dB, how many sweeps saw it and the likely service for that frequency.

Remember that every 10 dB is a factor of ten in power. A signal 20 dB above normal is about a hundred times stronger than usual for that spot. Large numbers like that are common near any transmitter, so "above normal" alone tells you that something was different, not that it matters.

Use marks well

Marks are your side of the record. The receiver knows what it measured; only you know what you saw. A good set of marks turns a puzzling spike into an explained one.

Types of mark

• Hold-to-talk voice marks. Hold the talk button and describe what you see. The note is pinned to the exact time and GPS position.
• One-tap labels. When you film something, tap what it is (car, van, truck, police, fire, federal, boat, aircraft and more) and the label is saved with the clip.
• Quick mark buttons. One tap for Vehicle, Antenna, Feeling it or Other, for when you can't talk.
• Marks from a linked phone. A second person can carry a linked phone and log marks while you carry the receiver. An iPhone can do this too, logging marks and GPS.

What to say in a voice mark

A useful mark answers what, where relative to you, and anything distinctive. Keep it short. Compare these:

Also mark things that explain gaps or oddities in the data: crossing under a highway, waiting at a long crossing, stepping into a shop, taking a detour, swapping the phone to the other hand. These are the details that you will have forgotten by the time you read the report.

A note on "Feeling it" marks

The Feeling it button records your own note that you felt something at that time and place. It's a personal log entry, like a diary note. It isn't a measurement and it isn't evidence that a signal caused anything. Lining it up with the spectrum shows only what was present at the same moment. If you're keeping these notes for a doctor or anyone else, present them as your observations.

Mind other people's privacy. Florida law requires the consent of everyone involved before a private conversation is recorded. Use hold-to-talk for your own notes, and release the button if someone starts talking to you.

When to record video

On paid plans, you can record short video evidence clips with the time, GPS position and RF readings burned into the picture. Video is powerful, but it's also the part of a survey most likely to capture other people. Use it deliberately.

Record video when

• There's a physical thing to show: an antenna on a roof, a new equipment cabinet on a pole, a vehicle with an unusual antenna parked in the same place again.
• The live display shows something you want to tie to a place, such as a level that rises as you approach a building and falls as you leave.
• You expect to show the finding to someone else, like a landlord, a utility, a regulator or a lawyer, and a picture of the location will save explanation.

Don't record video when

• It would mainly show people's faces, homes' interiors or number plates without a good reason.
• You'd need to step onto private property or point the camera through windows.
• A voice mark would do the job just as well.

Keep clips short and steady. Pan slowly from your position to the object, hold on it for a few seconds, and say nothing you wouldn't want in the record.

Verify a finding before you draw conclusions

Most unusual readings have ordinary explanations, and some aren't real signals at all. Work through these checks, in order, before treating a finding as meaningful.

1. Read the likely service

The report names the kind of service that normally uses each frequency. A flag at a cellular frequency near a cell site, a burst at 2.4 GHz outside a café, or a strong signal in a two-way radio band as a security patrol passes are what you'd expect. Check your marks for a vehicle, a work crew or an event at that moment.

2. Repeat the walk

Walk the same route at the same time on another day, with the same settings. A steady, fixed source shows up again in the same place. A one-off, such as a passing vehicle or a temporary event, doesn't. Two or three repeats that agree are far more convincing than one striking walk.

3. Move closer and farther

Signal strength falls with distance. In open space, doubling your distance from a source lowers the level by about 6 dB. In streets with buildings it falls faster and less predictably. If a signal rises by many dB over a few metres as you approach a spot and falls again as you leave, the source is near that spot. If it barely changes over a whole block, the source is probably far away and strong, such as a broadcast mast or a distant cell site.

4. Rule out receiver overload

Any receiver can be overloaded by a very strong signal. An overloaded HackRF can show signals that aren't really there, called spurs and intermodulation products. They look convincing but are created inside the receiver. To test for this:

1. Stand where the suspect signal was strongest.
2. Note its level and the level of a strong, known signal nearby, such as an FM station or a cell site.
3. Lower the LNA gain by 10 dB.
4. Look again. A real signal should drop by about the same 10 dB as everything else. A signal created by overload usually drops by much more, or vanishes entirely.

If a finding disappears when you reduce the gain, it was probably an artefact. Note that in a mark, and lower the gain for future walks on that route (which means starting a new baseline at the new setting).

5. Check the kit

A loose antenna, a damaged cable or a different antenna from last time can all change readings. So can your phone's own transmissions if the HackRF sits right next to it. If a whole walk looks different from the baseline, rather than one block or one frequency, check the kit before anything else.

6. Compare with a control

Walk a comparable street nearby with the same settings. If the same "unusual" signal appears there too, it's probably a feature of the wider area, not of the place you're investigating.

An unusual signal is not, on its own, evidence of anything harmful or illegal. It means only that something was different from normal for that block and time. Treat it as a starting point for the checks above.

Outdoor and indoor surveys

The method is the same indoors and out, but the conditions differ, and so do the pitfalls.

Because a home usually sits inside a single baseline block, an indoor survey relies on your own comparisons between rooms more than on the automatic baseline. Marks become essential: they are how you'll know which part of the walk was in which room.

A room-by-room home survey

This method gives a fair comparison between rooms in a flat or house. It takes about an hour for an ordinary home.

Before you start

1. Make a list of rooms and decide an order. Write it down.
2. List your own transmitters: Wi-Fi router, mesh points, smart speakers, cordless phone base, baby monitor, smart meter, games consoles, phones, tablets, smartwatches. These will appear in the survey, and you want to recognise them.
3. Choose your settings, usually the Common or Cellular & Wi-Fi range, and keep them fixed for the whole session.
4. Decide how you'll stand. Same height, antenna vertical, same distance from the walls each time.

The survey

1. Start outside the front door for two minutes as a reference, with a voice mark: "Outside front door, reference."
2. Enter the first room and say its name in a voice mark: "Kitchen, start."
3. Walk slowly around the room about half a metre from the walls, then stand in the centre for a minute.
4. Mark anything notable: "Standing next to the router", "By the window facing the street".
5. Say "Kitchen, end" as you leave.
6. Repeat for each room, in the same order.
7. Finish with another two minutes outside, so you can see whether anything changed during the session.

The comparison pass

Many people find that most of what they see indoors comes from their own devices. To check, repeat the survey with your own Wi-Fi router and other devices switched off, or at least note which were on. Any signal that disappears with your own devices off is yours. Anything that stays is coming from outside or from a neighbour.

Repeat the full survey at a different time of day, and on another day. As with an outdoor baseline, one session can't tell a regular signal from a one-off.

Reading the result

• Levels that are high everywhere but highest by a window facing a cell site are usually the cell site, getting in through the glass.
• Levels that peak next to one device and fall quickly as you step away are that device.
• Levels that are high in one room only, with your own devices off, deserve the verification checks above: repeat, move closer and farther, reduce gain.

If your concern is a hidden device, such as a tracker or a listening device, our guide on finding hidden GPS trackers and bugs explains what a spectrum survey can and can't find, and why many trackers only transmit occasionally.

Document a survey for others

A finding you can't show to anyone else has limited use. If you might need to share results with a landlord, a building manager, a utility, a lawyer or a regulator, build the record as you go.

What a good record contains

• The question you were trying to answer, written before you started.
• The kit: receiver, antenna, phone, and any cable or adapter.
• The settings: frequency range, LNA, VGA, RF amp on or off, calibration offset, and whether levels are in dBFS or dBm.
• The method: route, times, how many walks, whether learning was on or off for each.
• The findings: what was flagged, where, when, how far above normal, on how many walks.
• The checks: repeats, closer-and-farther passes, gain reduction tests, and what they showed.
• Your marks, including voice notes, with times and positions.
• The evidence package, unaltered.
• What you aren't claiming. A plain statement that the readings are relative levels, not certified field strength.

The evidence package

Each walk produces a report and a tamper-evident evidence package. It contains the raw measurements, your marks and voice notes, and a SHA-256 hash chain: each record's fingerprint includes the previous one, so changing any record afterwards breaks the chain. Anyone can check the chain independently using the instructions included. Download the package and keep it unaltered. Don't edit, crop or re-save its files; if you want to annotate, do it in a separate document that refers to the package. You can see what a finished report looks like in the sample report.

Write a short summary

Anyone you share with will read the first paragraph and maybe the table. Put the essentials there: "Between 3 and 10 March I walked the same 2 km route nine times. On five walks, a signal at about 460 MHz was flagged as new on the block outside 40 Example Street, peaking at the same spot each time and absent on the control street. It remained after I lowered the gain by 10 dB." That's clear, checkable and honest about its limits.

If the issue is interference with a licensed service, such as your radio, TV or another device, see our guide to documenting radio interference for an FCC complaint.

Privacy, recording and the law

A radio survey is a quiet activity, but it happens in places where other people live and work. Keep it lawful and considerate. This section is general information, not legal advice; laws vary by state and change over time.

Stay in public places

Survey from public pavements, streets and other places open to the public, or from property where you have permission. Don't enter private property, gardens, car parks or buildings without the owner's permission, and don't climb fences or walls to get a better reading. A reading taken from the pavement is just as useful for a record, and far easier to defend.

Recording conversations

Florida's law on intercepting communications, in chapter 934 of the Florida Statutes, generally requires the consent of all parties before a private conversation is recorded. Voice marks are for your own notes. If someone starts talking to you, release the talk button. If you record video in a place where people are having conversations, be aware that their voices may be captured, and keep clips short and focused on objects, not people.

Measuring, not listening

Consentiva measures how much radio energy is in each channel. It doesn't decode or record the content of transmissions. That's a deliberate design choice. Federal law restricts intercepting and sharing the content of many kinds of radio communication, so keep it that way: report levels and frequencies, not what you think a signal said.

Be considerate

• Don't point a camera at people's homes or children.
• Don't confront anyone about a reading. If you think a transmitter is causing a problem, document it and take it to the right authority.
• Never try to block or jam a signal yourself. Jamming is illegal under federal law; the FCC enforces it.

Weather and heat

In South Florida, heat is the main threat to a survey. Phones throttle their processors or dim their screens when they get hot, which can slow sweeps or pause the app. The HackRF also gets warm in use.

• Walk early or late in summer. If your baseline needs afternoon walks, keep them short.
• Keep the phone out of direct sun. A pocket in the shade of your body, or a light-coloured pouch, is better than holding it up to the sky.
• Don't seal the HackRF in a closed bag with no airflow on a hot day.
• Look after yourself. Carry water. A survey isn't worth heat exhaustion.
• Avoid rain. Neither the HackRF nor most adapters are waterproof. A sudden shower is a reason to stop and cover the kit.
• Never survey during a thunderstorm holding an extended antenna. Stop and go inside.

Battery management

The HackRF draws its power from the phone over USB, and the phone is also running GPS, the screen and the app. Battery drains noticeably faster than in normal use.

• Start with a full charge on every walk.
• Carry a power bank for walks of more than a couple of hours, and top the phone up between walks.
• Turn down screen brightness to a level you can still read; the screen must stay on, but it doesn't need to be at full brightness.
• Close other apps, especially navigation and video apps, which compete for GPS and processing.
• Watch for low-battery modes. Some phones restrict background activity or USB power when battery saver kicks in. Note in a mark if this happens, because it may affect the rest of the walk.

If you lose signal

Consentiva keeps an offline queue. If your phone loses its data connection during a walk, sweeps and marks are stored on the phone and uploaded later when the connection returns. Don't close the browser tab or clear site data before the queue has finished uploading. Check the walk in your reports once you're back online.

Sample plan: a one-week neighbourhood baseline

This plan builds a solid baseline for one route across all four time periods in a week. Adjust it to your schedule; what matters is that each period gets several walks on different days.

• Route: a 2 km loop from your front door, walked clockwise on the same side of each street, taking about 30 minutes at a steady pace.
• Settings: Common range (70 MHz–2.7 GHz), default gain, RF amp off, calibration offset zero. Written down on day one and not changed.
• Learning: on for every walk, unless something obviously unusual is happening.

At the end of the week you'll have three walks per period, which is enough for the app to compare later walks meaningfully. The marks from Monday become your map of fixed transmitters. Any block that flagged repeatedly during the baseline week is worth a closer look: it may be a place where the radio picture genuinely varies a lot, such as next to a busy junction or a construction site.

If four periods a day are too many, cut down to the periods that matter for your question, but keep at least three walks per period.

Sample plan: a one-off check of a specific concern

Sometimes you have one question about one place, such as a new equipment cabinet on a pole outside your building, and no wish to survey the whole neighbourhood. This plan answers it in about four days.

1. Day 1: define the question and the route. "Is there a signal near the new cabinet that isn't on the other blocks of this street?" Plan a short route that covers the cabinet's block, two blocks either side, and a comparable street nearby as a control. Fix your settings. Use the Cellular & Wi-Fi preset if the cabinet looks like telecoms equipment, or Common if you aren't sure.
2. Days 1–3: build a quick baseline. Walk the route once a day at the same time, with learning on. Mark the cabinet each time you pass it.
3. Day 4: investigation walk. Same time, same settings, learning off. Walk the normal route, then make three focused passes: towards the cabinet from the north, from the south, and from across the street. Mark the closest point each time.
4. Day 4: verification. If something peaks at the cabinet, stand at the peak, note the level, and lower the LNA gain by 10 dB to rule out overload. Record a short video clip of the cabinet with the readings burned in, if your plan includes video.
5. Review. In the report, check whether the finding is new or elevated, how many sweeps saw it, the likely service, and whether the control street shows it too.

The honest outcome is often something like "there's a cellular signal strongest at the cabinet, consistent with small-cell equipment". That's a result: it tells you what's there, and you can then look up who operates it or what the rules for it are.

Common mistakes and how to avoid them

Glossary

• Baseline: Consentiva's learned picture of the typical level in each 1 MHz channel, for each block of about 150 metres and each time period.
• Block: an area of about 150 metres used to group sweeps by location.
• Channel power: the average energy across a 1 MHz channel during a sweep.
• Control: a comparable place, walked the same way, where you don't expect anything unusual.
• dBFS: decibels relative to the receiver's full scale. Consistent with fixed kit and settings, but not an absolute power.
• dBm: decibels relative to one milliwatt, an absolute power. Consentiva shows dBm only when you enter a calibration offset.
• Elevated: a usual signal for that block and time that is much stronger than normal.
• Evidence package: the download containing a walk's raw measurements, marks and the hash chain.
• Gain: amplification in the receiver. The HackRF has the LNA (0–40 dB), VGA (0–62 dB) and RF amp (+14 dB).
• Hash chain: a sequence of SHA-256 fingerprints where each includes the previous one, so any change to an earlier record is detectable.
• Learning mode: the state shown when no baseline exists for a block and time period yet.
• Mark: your note, by voice or button, pinned to a time and GPS position.
• New: a signal at a frequency where there's normally nothing for that block and time.
• Overload: when a strong signal drives the receiver beyond what it can handle, producing false signals.
• Peak hold: the strongest level seen in a channel during a sweep, which catches short bursts.
• Polarisation: the orientation of a radio wave's electric field, typically vertical or horizontal. An antenna picks up less from the opposite polarisation.
• Sweep: one pass across the chosen frequency range.
• Unusual: a signal stronger than the baseline for that block and time period.

What a survey can't tell you

A careful survey tells you which signals were present, how strong they were relative to normal, where they were strongest and when they appeared. That's often enough to answer the question you started with. Add video of what was there when the signal peaked and you also have who or what was present. A survey doesn't measure exposure. An unusual signal is a difference from normal, so check it before drawing conclusions. If you need certified field-strength measurements, for example for regulatory compliance, use a calibrated instrument and a qualified RF engineer. For a sense of what an ordinary city street looks like on the spectrum, see radio signals on a Miami street.

Common questions

How many walks do I need before Consentiva can flag unusual signals?

Walk the same route at least two or three times on different days in each time period you care about. Until a block and period have a baseline, the app shows Learning instead of flagging anything.

Why should I keep the gain settings the same on every walk?

Gain shifts every reading up or down. If you change it, the whole spectrum looks different from the baseline even though nothing in the air changed, so start a new baseline if you must change it.

Should I leave "Use this walk to learn what's normal" switched on?

Leave it on for ordinary baseline walks. Switch it off when you are investigating something you think is unusual, so the unusual signal doesn't become part of normal.

How can I tell whether a strange signal is real or caused by overload?

Stand where it was strongest and lower the LNA gain by 10 dB. A real signal drops by about the same amount as everything else; an overload artefact usually drops by much more or disappears.

Can I survey inside my home?

Yes, but GPS is often poor indoors and a whole home usually sits in one baseline block. Use voice marks to name each room and compare rooms with each other, with your own devices on and then off.

Is it legal to walk around measuring radio signals?

Measuring signal levels from public places is generally lawful, and Consentiva doesn't decode the content of transmissions. Don't trespass, and don't record other people's conversations: Florida generally requires all parties' consent. This is general information, not legal advice.

Does a survey measure my RF exposure?

No. The readings are relative signal levels from an uncalibrated receiver unless you enter a calibration offset, and they aren't comparable with exposure limits. Certified measurements need a calibrated instrument and a qualified RF engineer.

What should I keep if I need to show my results to someone else?

Keep the unaltered evidence package for each walk, plus a short written summary of your question, kit, settings, method, findings and the checks you made. The SHA-256 hash chain lets anyone confirm the records weren't changed.