Chapter 3 · Describes DENKO Aurora firmware v487 and later · Updated 2026-11-01
Settings and automatic tuning
Where each setting's value comes from, which values the station tunes by itself, and what every setting does. You do not need to change anything for the station to work: it starts with values chosen for it and adjusts the important ones itself.
1. Where a value comes from
A setting can be given a value in five places. They are applied in this order:
Source
When it is applied
After a restart
1. Firmware default
Built into the firmware; used from power-on.
Restored. Changes only with a firmware update.
2. Station profile
Stations carry a profile in the firmware that holds some values. On current hardware it always holds the health-check noise limits; some stations also hold others, for example the detection method, the filter band or the timing correction. The station re-applies these every second, so a change you make to most of them is undone within a second. For the filter settings it usually waits 15 minutes after your change. A few held settings (ampk, cfarmin, selmin, deadveto) keep your value until the next restart, except that automatic tuning may still adjust ampk (section 2).
Restored.
3. Remote configuration from Denko
Downloaded 30 seconds after start and then every 2 minutes. It can hold values for all stations and for one station. A value is applied when it first appears or when Denko changes it.
Applied again about 30 seconds after every start. If Denko removes a value, the station keeps it until its next restart.
4. Automatic tuning
A few values are adjusted by the station itself while it runs (section 2).
Starts again from the default, about 30 seconds after start.
5. Your changes
The controls in the web interface and /set? addresses. Most apply immediately; filter changes are queued.
Lost, except the network choice (netenable), which firmware v482 and later stores. A restart happens at least once a day, after every firmware update and after a power cut.
A later source does not always win: a value held by the station profile comes back within a second, and the remote configuration is applied again at every start. For a lasting setting change, ask Denko to set it in the remote configuration. The locally stored network choice is the exception described above.
2. What the station tunes by itself
Nothing needs to be started: automatic tuning is on by default. It begins about 30 seconds after start, once the station has measured its trigger rate.
Value
How it is tuned
How to stop it
khi slope threshold
Used by the default (slope) detection method. Every 30 seconds the station looks at how often the detector triggered: more than 20 per second raises the threshold by 2, more than 8 per second by 1, and fewer than 1 per second lowers it by 1, but only if a lower value would not flood the station with noise. Range 4–48, starting at 12. If the antenna appears dead, it returns to 12 and waits.
khiauto=0, or set khi yourself (tuning then stays off until the next restart).
ampkq amplitude threshold
Used by the amplitude and envelope methods. Every 60 seconds the station looks at how many signals it reported: more than 3 per second raises the threshold by 4 at once, and more than 1.5 per second in five checks in a row raises it by 1. It never lowers the threshold because the sky is quiet, since a quiet sky and a too-strict threshold look the same. Range 68–160: after any manual change it waits 15 minutes, and then also brings a value outside this range back inside it (so a hand-set ampk above 10 returns to 10).
ampkauto=0.
cfarmin contrast minimum
When cfarmin is positive, has not been set by an operator and the station profile allows adjustment, the station can lower it once per start. It waits at least an hour and 10,000 triggers, requires a working input, and lowers the value only if the observed contrast never reached it. A manual or remote setting pins it.
Set cfarmin yourself.
Health check
Judged every 5 seconds; decides whether reports are held back (chapter 2).
hgate=0 (not recommended).
caprank, pbf
Adapt themselves while switched on. Both are off by default.
Set them to 0.
100 Hz mode
Switching lfmode on sets three filters together (hpfhz, drechz, hpfrac); switching it off sets both high-pass filters back to 4 kHz and restores hpfrac.
lfmode=0.
3. Every setting
Kept after restart: “Remote” means the value survives a restart only when Denko sets it in the remote configuration; a value you set yourself is always lost at restart. “Stored” means the station also keeps a value you set yourself (firmware v482 and later). Changed automatically: what else can change the value (section 1 and 2). Advice: “In the web interface” — you may use the control as described in chapter 1; “Leave” — leave it to the station and Denko; “Service only” — factory and diagnostic use, do not use.
Further settings exist for factory testing and service. They are deliberately not listed here: do not use any setting that is not in this chapter.
Lightning indicators (firmware v482 and later)
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
ledmode
Which located events light the white magnitude bar: 0 = our timestamp was used by the locator (default); 1 = network lightning within 250 km, even if this station did not contribute. The Lightning indicators selector on the Live Scope tab. Used events show the magnitude of the station’s reported signal. Nearby events show the lowest step because the network does not provide signal magnitude. No confirmation means no event flash; late or duplicate messages are ignored. Any value other than 1 means 0.
0
0/1
Remote
Remote value is applied when it changes; local choice lasts until then or restart
In the web interface
Startup antenna measurement
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
sweepboot
Starts enabled at each boot: measures for 30 seconds from acquisition start instead of detecting lightning. 0 cancels an unfinished startup measurement; 1 does not start another. Remote configuration arrives too late to reliably prevent the next startup measurement. Capturing the physical test signal depends on power-on timing and is not yet verified.
1
0/1
Remote
Reset to 1 at restart; remote value applied later
Service only
sweep
Measures the antenna’s frequency response in place for this many seconds; while it runs, lightning detection pauses. An out-of-range value is refused, not limited.
0
0–60
No
—
Service only
Detection threshold
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
amp
Detection method: 0 = slope (rate of change), 1 = amplitude, 2 = envelope. Decides which threshold below is in use.
0
0–2
Remote
Station profile
Leave
khi
Threshold of the slope method, in multiples of the background variation. Higher = less sensitive.
12
1–64
Remote
Automatic tuning (section 2)
Leave
khiauto
Automatic tuning of khi: 1 = on, 0 = off.
1
0/1
Remote
Station profile
Leave
ampk
Threshold of the amplitude and envelope methods, in whole multiples of the noise floor. Sets ampkq to 16 × ampk.
8
2–64
Remote
Station profile; automatic tuning via ampkq
Leave
ampkq
The same threshold in steps of 1/16.
128
32–1024
Remote
Automatic tuning (section 2); station profile via ampk
Leave
ampkauto
Automatic tightening of ampkq: 1 = on, 0 = off.
1
0/1
Remote
—
Leave
devmin
Smallest background variation the slope method assumes, so the threshold cannot collapse on a very quiet input.
2
1–1024
Remote
—
Leave
nfslow
Amplitude methods: use the 12-minute minimum noise floor instead of the running one.
0
0/1
No
—
Leave
thrabs
Fixed threshold in raw converter units, replacing the relative one. 0 = off.
0
0–16777216
Remote
—
Leave
thrfloor
Lower limit for the threshold, in raw converter units. 0 = off.
0
0–16777216
Remote
—
Leave
statdec
Updates the slow statistics less often to save processing time. 0 = off.
0
0–4
No
—
Service only
slopeavg
Averaged slope estimate (diagnostic).
0
0/1
No
—
Service only
Re-arming after a detection
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
refovr
Lets the detector trigger again during its re-arm time if a new signal is more than refovr/16 times the previous peak. 0 = off.
24
0 or 16–255
Remote
—
Leave
envshift
Release time of the envelope follower (10 = 2 ms).
10
4–10
Remote
—
Leave
deadus
Fixed pause after each capture, in µs.
2000
0–50000
Remote
—
Leave
deadveto
Shorter pause (0.25 ms instead of 2 ms) after a candidate that was rejected.
0
0/1
No
Station profile
Leave
refmax
Longest allowed re-arm time, in samples (51200 = 100 ms).
51200
16–51200
Remote
—
Leave
Additional detection stages
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
cfararm
Additional trigger based on contrast with the signal just before it. 0 = off.
0
0–4096
Remote
—
Leave
cfar2
A second, guarded version of the contrast trigger. 0 = off.
0
0–4096
Remote
—
Leave
sbcfar
Contrast trigger on weighted frequency sub-bands. 0 = off.
0
0–65535
Remote
—
Leave
cfarmin
Minimum contrast a detection must have to be reported. 0 = measure only.
0
0–65535
Remote
Station profile; lowered once (section 2)
Leave
Selecting what is reported
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
selmin
Minimum contrast score for the selector. 0 = off.
0
0–20000
Remote
Station profile
Leave
selgap
Pause after a selected report, in µs.
200000
0–2000000
Remote
—
Leave
durmin
Minimum number of samples above the threshold within 125 µs. 0 = off.
0
0–64
Remote
—
Leave
caprank
When the limit of 50 reports per second is reached, send the strongest candidates rather than the first ones.
0
0/1
Remote
Adapts itself when on
Leave
imp
Minimum impulsiveness of a signal, per mille. 1000 = off.
1000
1–1000
Remote
—
Leave
magmin
Minimum signal strength (0–7, the white-bar scale) for a signal to be detected and reported. 0 = all. The detect ≥ selector on the History tab.
0
0–7
Remote
—
In the web interface
magdb0
Where the strength scale starts, in dB (slope method). With magmin above 0 it also moves the detection limit.
18
0–60
No
—
Leave
hpfrac
Minimum share of a signal's energy above 4 kHz, in %, for it to count as lightning.
3
0–100
Remote
100 Hz mode sets it to 0
Leave
pbf
Blocks signals whose energy keeps falling in the same narrow band (interference). 0 = off.
0
0–9
Remote
Adapts itself when on
Leave
net
Threshold of the learned confirmation stage. 0 = off. Switching it on also widens the filters.
0
integer
No
Station profile
Service only
dense
Switches experimental detector scoring on or off. With densethr = 0 it only scores; a non-zero densethr also enables its detection threshold.
0
0/1
No
Station profile via densethr
Service only
densethr
Threshold of the experimental detector; non-zero also switches it on.
0
±2^30
No
Station profile (within 1 s)
Service only
txblank
Blocks triggering for this many µs after each Wi-Fi transmission.
0
0–20000
Remote
—
Leave
Frequency band and filters
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
fc
Upper edge of the measurement band (low-pass), in kHz. 0 or 250 and above = full width. The filter buttons and field on the Live Scope tab.
24
0 (WIDE), 1–243; ≥250 = WIDE
Remote
Station profile (usually after 15 min)
In the web interface
hp
Lower edge of a band-pass in the measurement filter, in kHz. Leave at 0: at the default upper edge of 24 kHz the station refuses it, and a large value can move the upper edge (fc) far outside the lightning band.
0
0–128
Remote
Station profile
Leave
hpf
High-pass filter of the detector, in kHz. Removes mains and other low-frequency noise. 0 = off. It cannot go above 80 % of fc (19.2 kHz at the default).
4
0–115, max 80 % of fc
Remote
Station profile; 100 Hz mode
Leave
hpfhz
The same filter, in Hz. 0 = off.
4000
0 or 10–115200, max 80 % of fc
Remote
Station profile; 100 Hz mode
Leave
drechz
High-pass of the recording used for the noise figures and for waveform retrieval, in Hz.
4000
5–25600
Remote
100 Hz mode
Leave
lfmode
100 Hz mode: sets the detector and recording high-pass to 100 Hz and turns the 4 kHz check off. 0 sets lightning mode: both high-pass filters are set back to 4 kHz, even if the station was not in 100 Hz mode. The mode switch on the Live Scope tab. On stations whose profile sets the detector high-pass, the profile can restore that part within a second; a direct hpf or hpfhz change from the web interface instead holds the profile off for 15 minutes.
0
0/1
Remote
Station profile (partly, within 1 s)
In the web interface
inotch1
Notch filter 1 for fixed-frequency interference: centre frequency in Hz. 0 = off.
0
0 or 1000–115200
No
—
Leave
inotch2
Notch filter 2: centre frequency in Hz. 0 = off.
0
0 or 1000–115200
No
—
Leave
inotchq
Sharpness (Q × 10) of both notch filters.
580
10–5000
No
—
Leave
notch
Notch in the measurement filter: centre frequency in Hz. 0 = off.
0
0 or 1000–30000
Remote
—
Leave
notchbw
Width of that notch, in Hz.
2000
250–6000
Remote
—
Leave
Mains interference
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
comb
Mains comb filter: delay in samples. 0 = off.
0
0 or 7314–12799
Remote
—
Leave
mains
Satellite-timed tracker of the 50 Hz mains wave.
0
0/1
No
Station profile
Leave
msub
Subtracts the tracked mains wave from the signal (needs mains = 1).
0
0/1
No
—
Leave
Timing and reporting
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
toa
Timing correction in ns, subtracted from every reported time. Set per station by Denko.
53000
±2000000
Remote
Station profile
Leave
netenable
Selects the optional lightning network. On firmware v482 and later: Denko is always on and cannot be switched off. 2 = Denko only; 3 = both (the default). Legacy values 0 and 1 mean 2 and 3. Switching the lightning network off stops its registration and detection reports; switching it on starts registration again, using this station’s configured identity. A new dashboard save takes priority over an earlier local choice; an unchanged automatic check preserves the local choice. The station has room to store a limited number of changes. When it is full, a change still takes effect at once but lasts only until the next restart, and the Status page shows “storage full”; after a restart the station usually starts with Denko only until the dashboard’s choice is applied again, so make further changes from the dashboard. The station stores the choice, so it is kept after a restart, and reads it from the remote configuration only from this station’s own entry. Values outside 0–3 are refused. On firmware before v482 the value is a plain choice of networks and is not stored: 0 = no network (the station sends no detections), 1 = the optional network only, 2 = Denko only, 3 = both.
3
0–3
Stored
Owner selection
In the web interface
detail
Reports to Denko's own server: 1 = detailed 16-bit, 0 = compatible 8-bit.
1
0/1
No
—
Leave
collector2_ip
The station operator’s own receiver, which receives a complete, byte-for-byte copy of every packet this station sends to Denko, including its processor ID. Denko keeps receiving everything as before. Set by Denko only with the owner’s consent, per station, together with collector2_port; it cannot be set from the web interface. 0 = off. An invalid address is refused, not changed. From firmware v447.
0
IPv4 address or 0
Remote
—
Leave
collector2_port
The port of the collector2_ip server. 0 = off. A value above 65535 is refused, not limited. From firmware v447.
0
0–65535
Remote
—
Leave
polinv
Swaps the antenna’s polarity in software, as if its two leads were exchanged. An installation property, set by Denko for your station.
0
0/1
Remote
—
Leave
encrypt
Sends the detection reports in encrypted form. Set by Denko for your station; the wrong value stops the reports from being understood.
0
0/1
Remote
—
Leave
lmgain
The gain of your station’s front-end as declared with each report, in tenths (84 = 8.4). Calibrated per front-end; the receiver reconstructs signal amplitudes from it.
84
1–99999
No
—
Leave
reboot
reboot=1 restarts the station cleanly, as if it were switched off and on. Changes you made yourself are lost (section 1).
—
1
No
—
Leave
Satellite receiver
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
gnssab
Minutes between switches of the satellite receiver between alternative constellation configurations. 0 restores the base configuration.
0
0–1440
Remote
—
Service only
gnsscfg
Pins the satellite receiver to one constellation configuration (0–8); other values are ignored. gnsscfg=-1 together with confirm=coldstart resets the receiver to its factory state, and it then needs several minutes to find satellites again.
0
0–8
Remote
—
Service only
gnssbase
The factory base configuration of the satellite module, packed into a number. Captured and set by Denko per station. Firmware v427 and later.
0
packed value
Remote
—
Service only
Health check
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
hgate
Holds back reports while the health check fails (chapter 2). 0 = information only.
1
0/1
Remote
Station profile
Leave
nbndmin
Lowest background noise level a healthy station should show, in raw units. A value above a non-zero nbndmax is refused. Below it the health line shows nbndlo; from firmware v482 that is for information only and does not hold back reports.
100 (current hardware: 200)
0–20000
Remote
Station profile (within 1 s)
Leave
nbndmax
Highest background noise level for a healthy station. 0 = no limit. A non-zero value below nbndmin is refused. Above it the health line shows nbndhi; from firmware v482 that is for information only and does not hold back reports. Set by Denko only; not available locally.
8000 (current hardware: 40000)
≥ 0
Remote
Station profile (within 1 s)
Leave
nbndreset
Starts a new site survey (use nbndreset=1). The Start a new survey button on the Status tab.
—
1
No
—
In the web interface
gnssant
Type of satellite antenna, used only to judge its antenna fault report: 0 default (the standard passive antenna), 1 active, 2 passive. Denko sets it for your hardware; the station pages have no control for it. An antenna feed that draws no current ("open") is normal for a passive antenna and is a fault only with 1. The GNSS tab shows the default as "passive (default)". Reporting is not affected.
0
0/1/2
Remote
—
Leave
Firmware updates
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
ota_max
Highest firmware version Denko permits this station to install automatically. 0 = no version limit. Set only in remote configuration, not from the station web page. A hold appears as v… held (ota_max …) at /ota. Removing the limit lets the next check proceed.
0
0 or positive integer
Remote
Denko remote configuration
Service only
Station login
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
auth_req
Require a login token for changes made on the station web page (chapter 1, section 5.5): 1 = on, 0 = off. Taken only from this station's own entry of the remote configuration, never from a fleet-wide line and never from the web page. After every restart, changes from the web page and token login are refused until the login settings have arrived, and the page says "Waiting for station configuration" (chapter 1, section 5.5). On firmware v482 and later, a successful, complete remote configuration download whose station entry has neither login setting (or with no station entry) means auth_req=0 and auth_nb=0. Failed or incomplete downloads, invalid values and entries with only one setting do not enable changes or token login after a restart. Firmware v469 to v481 needs auth_req and auth_nb together after every restart: a missing value, or only one of the two, does not keep the earlier setting, so to keep login off on that firmware both must be set to 0 explicitly. On earlier firmware the station keeps the last value it received across restarts, so a missing value leaves it as it was; only an explicit 0 turns it off. Set by the station owner from the Denko dashboard.
0
0/1
Remote
Station owner (dashboard)
Service only
auth_nb
Refuse every login token issued before this time (Unix seconds), and end the logins made with them. 0 = none refused. Taken only from this station's own entry. On firmware v482 and later, a completed download with neither setting means 0 for both; a single setting or invalid value is still refused. Firmware v469 to v481 requires it together with auth_req after every restart (see auth_req); on earlier firmware it is kept across restarts like auth_req.
0
0–4294967295
Remote
Station owner (dashboard)
Service only
Display and service adjustments
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
oled
Display refresh: 1 = enabled; 0 = stop refreshing, leaving the last picture on screen. Diagnostic use only.
1
0/1
No
—
Service only
sclk
Readout clock request in kHz. The actual rate is rounded to one the station can produce. Refused outside the range or during an update; changing it interrupts measurement. Leave it to Denko.
17142.857 kHz
8000–22000
No
—
Service only
sdly
Readout timing adjustment. A wrong value can corrupt the measured signal. Refused outside the range or during an update; service only.
2
0–4
No
—
Service only
slag
Readout lag compensation. It changes the scale of the measured signal. Refused outside the range or during an update; service only.
0
0–3
No
slagauto when enabled
Service only
prebuf
Measurement-input buffer. 1 = on, 0 = off. Changing it interrupts measurement; refused during an update. Service only.
0
0/1
No
—
Service only
clkdiv
Measurement clock diagnostic: 1 = normal, 8 = diagnostic. Diagnostic mode holds back reports and returns to normal after about 10 minutes. Refused during an update; service only.
1
1/8
No
Returns to 1 after 10 min
Service only
Signal readout
Setting
What it does
Default
Range
Kept after restart
Changed automatically
Advice
slagauto
Once per start, about a minute after power-on, the station checks whether it reads the converter one bit late and, if it clearly does, corrects it and checks the correction. Signal levels then read twice as high. Off by default; Denko enables it per station.
0
0/1
Remote
Once at start, when on
Service only
4. Changing a setting, and undoing it
Open http://<IP address>/set?<name>=<value>. Several settings can be changed at once: /set?fc=24&magmin=0. Most changes apply immediately; filter changes are queued. Check the resulting value, not just the acknowledgement. The web interface sends these changes with POST /set. If login is required, use its controls after logging in; a bare address in the browser does not include your token.
Out-of-range values are limited to the range, some limits depend on other settings (the high-pass, for example, cannot exceed 80 % of fc), and a few values are ignored. The exceptions include netenable, sweep, sweepboot, notch and notchbw: an out-of-range value is refused and the previous value stays in force. For ledmode, any value other than 1 means 0. For most settings the reply is just {"ok":1}, whatever happened; check the result on the Status tab or in /status.json. The health bounds also refuse a value that would put the minimum above a non-zero maximum. Changes to fc or hp reply with the accepted request and the profile-hold time; cutoff_khz in /status.json shows the filter after the queued change has been applied and checked.
To undo every change you made, restart the station (switch it off and on). It returns to its defaults, its profile and Denko's remote configuration. The network choice (netenable) is the exception on firmware v482 and later: it is stored, so set it back yourself.
If a change is undone by itself within a second, the setting is held by the station profile. If it is undone after about 15 minutes, it is a filter setting held by the profile. If it creeps back up over minutes, automatic tuning is adjusting it. A change that stays until restart can still be a profile setting: ampk, cfarmin, selmin and deadveto keep your value until then (ampk subject to automatic tuning).
The station works best on its own settings. Change a setting only if you know what it does, and restart the station if a change made things worse.
