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nband

Reference

Fourteen bands, and what each one is bad at.

An object that shows up in one band is a story. An object that shows up in four different physical channels at the same instant is a measurement. This page is what each of those channels can and cannot do, because the limits matter far more than the capabilities: almost every false alarm in a system like this comes from someone forgetting one.

10-14 m10-8 m10-3 m103 m
GammaUltravioletVisibleNear infraredShort-wave infraredLong-wave infraredMillimetre waveRadio frequencyMagnetic and ELF/VLF
Not electromagneticAcoustic and infrasoundSeismicGravimetricEnvironmentalNavigation and pose

All 14 bands

Ordered by increasing wavelength, which is also the order they appear in the schema and in the database enum. An event needs at least two detection bands to agree before it can be called unresolved.

Detection bands · 12

Channels that can produce a detection

Gamma

0.01 pm – 10 pm

Ionizing photons above 100 keV.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainstrong
fogstrong
smokestrong

Practical reach

30 m

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$189

lowest registered part that opens this band

Detectsnothing in the reference set
Blind toAircraftSatelliteBird or insectMeteorSmall droneBalloonExhaust plumeRF emitterGround vehicle

Parts that open this band

CsI(Tl) + SiPM open gamma spectrometer$189 · T3

What it picks up

Radioisotope decay, cosmic-ray secondaries, and any source emitting hard photons. The only band in the stack that responds to nuclear rather than thermal or electronic processes.

Where it fails

Counting statistics dominate. A small scintillator sees roughly 20-60 counts per second of background, so a real excursion needs either a large deviation or a long integration. Air attenuates low-energy gammas strongly, which caps useful range at tens of metres for weak sources.

Ultraviolet

100 nm – 400 nm

100 to 400 nanometres, above the violet edge of vision.

Works when

daylightblind
darknessstrong

Sees through

cloudblind
rainblind
fogblind
smokemarginal

Practical reach

5.0 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$25

lowest registered part that opens this band

DetectsMeteorLightningExhaust plume
Blind toSatelliteBird or insectSmall droneBalloonRF emitter

Parts that open this band

AS7331 UVA/UVB/UVC sensor$25 · T2, T3

What it picks up

Corona discharge, electrical arcing, plasma, combustion, and lightning leaders. Solar UV sets the daytime floor, so the band is far more informative after dark.

Where it fails

Ordinary glass blocks most of it, so the sensor needs a quartz or fused-silica window. Atmospheric ozone absorbs hard UV entirely. Daytime dynamic range is brutal: the Sun is roughly six orders of magnitude above any plausible target.

Visible

380 nm – 750 nm

380 to 750 nanometres, the band your eye already covers.

Works when

daylightusable
darknessstrong

Sees through

cloudblind
rainblind
fogblind
smokeblind

Practical reach

30 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$78

lowest registered part that opens this band

DetectsAircraftSatelliteBird or insectMeteorLightningSmall droneBalloonExhaust plumeGround vehicle
Blind toRF emitter

Parts that open this band

HQ Camera (IMX477) + 6mm CS lens$78 · T1, T2, T3

What it picks up

Anything that reflects sunlight or emits its own light: aircraft, satellites, meteors, balloons, birds, and the occasional thing that fits none of those. Provides the astrometry that turns a detection into a bearing.

Where it fails

Useless through cloud and nearly useless in daylight against a bright sky for dim targets. A single camera gives bearing but never range, which is why nband treats single-node visible detections as unresolvable in distance by construction.

Near infrared

750 nm – 1.4 µm

750 to 1400 nanometres, just past the red edge.

Works when

daylightmarginal
darknessstrong

Sees through

cloudblind
rainmarginal
fogmarginal
smokemarginal

Practical reach

20 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$96

lowest registered part that opens this band

DetectsAircraftSatelliteMeteorLightningSmall droneBalloonExhaust plumeGround vehicle
Blind toRF emitter

Parts that open this band

HQ Camera NoIR + 850nm bandpass$96 · T1, T2, T3850 nm pulsed IR beacon, 5 W peak$34 · T3

What it picks up

Hot exhaust, incandescent surfaces, IR illuminators and rangefinders, and haze-penetrating reflected light. Silicon sensors are natively sensitive here, so removing the IR-cut filter from a normal camera buys the band for free.

Where it fails

Sensitivity falls off a cliff past 1100 nm where silicon stops absorbing. Sunlight is rich in NIR, so daytime contrast is poor. Without a bandpass filter the channel is contaminated by ordinary visible light.

Short-wave infrared

1.4 µm – 3 µm

1.4 to 3 micrometres. Reflective, not thermal.

Works when

daylightusable
darknessstrong

Sees through

cloudblind
rainmarginal
fogusable
smokeusable

Practical reach

25 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$2.4k

lowest registered part that opens this band

DetectsAircraftMeteorSmall droneBalloonExhaust plumeGround vehicle
Blind toRF emitter

Parts that open this band

InGaAs 640x512 SWIR module$2400 · T3

What it picks up

Sees through haze, thin smoke, and some fog far better than visible light. Discriminates materials by reflectance in a way no other band in this stack can. Night-sky airglow illuminates targets passively at 1.5 to 1.7 micrometres.

Where it fails

Requires an InGaAs sensor. This is the single most expensive band per pixel in the platform and the reason tier 3 exists. Water vapour absorption bands carve holes in the spectrum.

Long-wave infrared

8 µm – 14 µm

8 to 14 micrometres. Pure thermal emission.

Works when

daylightstrong
darknessstrong

Sees through

cloudblind
rainmarginal
fogmarginal
smokestrong

Practical reach

8.0 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$75

lowest registered part that opens this band

DetectsAircraftBird or insectSmall droneExhaust plumeGround vehicle
Blind toRF emitter

Parts that open this band

Lepton 3.5 + PureThermal 3$329 · T2, T3MLX90640 32x24 thermal array$75 · T1

What it picks up

Everything warmer than absolute zero, by its own emitted heat rather than reflected light. Works in total darkness and through smoke. A radiometric sensor reports actual temperature per pixel, which turns a track into an energy-budget measurement.

Where it fails

Resolution is low and expensive to increase; 160x120 is the affordable tier. Germanium optics only, which are costly and fragile. Uncooled microbolometers drift, so a shutter-based flat-field correction interrupts the stream every few minutes.

Millimetre wave

3.7 mm – 1.25 cm

24 to 81 gigahertz active radar.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainmarginal
fogstrong
smokestrong

Practical reach

250 m

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$15

lowest registered part that opens this band

DetectsAircraftSmall droneGround vehicle
Blind toSatelliteMeteorLightningExhaust plumeRF emitter

Parts that open this band

LD2450 24 GHz tracking radar$15 · T2IWR6843ISK 60 GHz mmWave$299 · T3

What it picks up

The only band in the stack that measures range and radial velocity directly, by illuminating the target and timing the return. Gives the discriminator a physical distance, which is what converts an angular track into a real trajectory.

Where it fails

Short range for small radar cross-sections: a few hundred metres for a drone-sized target with a hobby module. Rain attenuates heavily. Ground clutter and multipath produce persistent false returns that have to be learned and subtracted per site.

Radio frequency

5 cm – 600 m

500 kilohertz to 6 gigahertz, received passively.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainstrong
fogstrong
smokestrong

Practical reach

300 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$40

lowest registered part that opens this band

DetectsAircraftSatelliteLightningSmall droneBalloonRF emitter
Blind toBird or insectExhaust plume

Parts that open this band

RTL-SDR Blog V3$40 · T1, T2, T3

What it picks up

Emissions rather than reflections. Aircraft transponders, satellite downlinks, control links, broadband impulsive noise from discharge events, and anything transmitting where nothing should be. Also feeds passive radar: an aircraft crossing a broadcast transmitter's illumination produces a Doppler-shifted echo.

Where it fails

The spectrum is crowded and every site has a unique interference fingerprint that must be characterised before anything can be called anomalous. A single antenna gives no bearing without a rotator or a coherent multi-receiver array.

Magnetic and ELF/VLF

10000 m – 10000000 m

DC to 30 kilohertz field measurement, not photon detection.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainstrong
fogstrong
smokestrong

Practical reach

30 m

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$40

lowest registered part that opens this band

DetectsLightningGround vehicle
Blind toSatelliteBird or insectMeteorBalloonExhaust plume

Parts that open this band

RM3100 3-axis geomagnetic sensor$40 · T2, T3

What it picks up

Static and slowly varying magnetic fields, sferics from distant lightning, power-line harmonics, and any moving ferromagnetic or current-carrying mass close enough to perturb the local field. This is the band that has historically carried the most repeatable anomalous reports.

Where it fails

Falls off as the cube of distance for a dipole source, which makes it a close-range channel: metres to low tens of metres for anything realistic. The Earth's 25 to 65 microtesla background is five orders of magnitude larger than any plausible signal, so everything depends on differential measurement and gradiometry.

Acoustic and infrasound

0.05 Hz – 20 kHz

0.05 hertz to 20 kilohertz pressure waves.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainmarginal
fogstrong
smokestrong

Practical reach

12 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$13

lowest registered part that opens this band

DetectsAircraftLightningSmall droneGround vehicle
Blind toSatelliteBalloonExhaust plumeRF emitter

Parts that open this band

ICS-43434 I2S MEMS microphone$13 · T2, T3

What it picks up

Propeller and rotor signatures, jet noise, sonic booms, and the infrasound tail that survives to long range when audible sound has already been absorbed. Independently corroborates or refutes a claim that an optical track was silent.

Where it fails

Sound arrives seconds after light, so acoustic correlation needs a range estimate to line up. Wind noise dominates infrasound and requires a mechanical wind filter to suppress. Urban sites are close to unusable below 100 hertz.

Seismic

0.01 Hz – 100 Hz

Ground motion from 0.008 to 100 hertz.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainusable
fogstrong
smokestrong

Practical reach

3.0 km

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$89

lowest registered part that opens this band

DetectsGround vehicle
Blind toSatelliteBird or insectSmall droneBalloonExhaust plumeRF emitter

Parts that open this band

SM-24 geophone element$89 · T3ADS1256 24-bit delta-sigma ADC board$28 · T3

What it picks up

Ground-coupled acoustic energy from low overflights, and, at high-tier sites, the vibration reference a gravimeter needs to separate real gravitational signal from the ground moving underneath it.

Where it fails

Almost entirely a noise-characterisation channel at low tiers. Cultural noise from roads and machinery swamps everything below a few hertz at any site near people.

Gravimetric

,

Absolute local gravitational acceleration.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainstrong
fogstrong
smokestrong

Practical reach

100 m

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$150k

lowest registered part that opens this band

Detectsnothing in the reference set
Blind toSatelliteBird or insectMeteorLightningSmall droneBalloonExhaust plumeRF emitterGround vehicle

What it picks up

The only channel that responds to mass-energy directly rather than to photons or fields. A discrepancy between the mass implied by radar cross-section and the mass implied by gravitational perturbation is a measurement no other instrument in the stack can produce.

Where it fails

Research tier only, and not reachable today. Atom-interferometer gravimeters cost six figures and need vibration isolation and a co-located seismometer for noise subtraction. A 1000 kilogram object at 50 metres produces roughly 2.7 nanogal, three to four orders of magnitude below any portable instrument: a transportable atom interferometer sits around 50 microgal and the best absolute gravimeters around 2 microgal, and no amount of integration time closes that gap for a transient. The band is defined because the schema should be able to represent a measurement it cannot yet make, and because absence should be recorded rather than assumed. No nband node carries one, and none is expected to.

Context bands · 2

Channels that can never produce a detection

These exist so that every detection carries the conditions it was made under. Treating an environmental excursion as a detection is a well-documented failure mode of amateur sensor networks, so the discriminator will not score on these alone, by construction rather than by policy.

Environmental

,

Pressure, temperature, humidity, wind, sky quality, cloud cover.

Works when

daylightstrong
darknessstrong

Sees through

cloudstrong
rainstrong
fogstrong
smokestrong

Practical reach

0 m

order of magnitude for an aircraft-sized target in good conditions

Cheapest way in

$23

lowest registered part that opens this band

Detectsnothing in the reference set
Blind toAircraftSatelliteBird or insectMeteorLightningSmall droneBalloonExhaust plumeRF emitterGround vehicle

Parts that open this band

BME688$23 · T1, T2, T3INA226 bidirectional current and power monitor$12 · T2, T3

What it picks up

Nothing on its own. It exists so that every detection carries the atmospheric state it was made under, which is what allows a refraction artefact, a temperature inversion, or a wet radome to be ruled in or out afterwards rather than argued about.

Where it fails

Not a detection channel. Treating an environmental excursion as a detection is a known failure mode of amateur sensor networks and the discriminator refuses to score on it alone.