Privacy Policy

Last updated: October 2026

1. Controller

Torsten Silovsky
Stollberger Straße 64, 09119 Chemnitz, Germany
Email: info@hoong.de · Phone: +49 (0)3721 27 05 20

2. Purpose

This website provides real-time visualizations of lightning detections and sensor network data. No user registration, analytics, or advertising tracking is used.

3. Data from sensor devices (network participants)

• Lightning events (“strikes”): timestamps, distance estimates, and the reporting device's GPS position.
• Heartbeat telemetry: device status such as temperature, humidity, signal strength (RSSI), uptime, firmware version, and—if available—GPS coordinates.
• Device metadata: a technical device identifier and the device's IP address, which is anonymized before storage (last octet removed).

Device GPS positions typically correspond to the location where a participant operates their sensor (e.g., their home) and are therefore treated as personal data of the participant. Publicly visible map data only contain coordinates coarsened to a grid of roughly 1 km; precise positions are not published. Device identifiers are technical IDs without names or contact data.

4. Legal basis

Article 6(1)(f) GDPR (legitimate interests). The legitimate interest is the operation and improvement of a community lightning detection network. Participants connect their devices voluntarily and can stop transmission at any time by disconnecting their device.

5. Map tiles (Mapbox) — consent-based, third-country transfer

The interactive map loads tile images from Mapbox Inc., 740 15th Street NW, Washington DC, USA. No request is sent to Mapbox until you actively click “Show map” (two-click solution). Only after your consent are map tiles loaded; at that point your IP address and technical request data are transmitted to Mapbox in the United States.

Legal basis: your consent, Article 6(1)(a) GDPR. Transfer safeguard: EU standard contractual clauses / EU-US Data Privacy Framework (see Mapbox Privacy Policy).

If you tick “Remember my choice”, your consent is stored in your browser's local storage on your device only. You can withdraw your consent at any time via the “Reset map consent” link in the page footer or by clearing your browser's site data; map tiles will then only load again after a new consent. All other scripts and styles are hosted on our own server; no other third-party requests are made.

Cloud layer (satellite images): The optional cloud layer shows Meteosat infrared images from EUMETSAT (Darmstadt, Germany). Your browser loads these images exclusively from our own server; our server fetches them from EUMETSAT and stores them temporarily. No data about you is passed to EUMETSAT. Whether the layer is shown is stored in your browser's local storage only.

6. Browser location (optional)

After you enable the map, your browser may ask for permission to use your location. If you allow it, your position is used only locally in your browser to center the map, to show it as a blue dot and to calculate the distance to the nearest impact point. It is never transmitted to our server or stored. If you decline, a default map view is shown.

6a. Discord community link

This website links to a community server operated on Discord Inc., 444 De Haro Street, San Francisco, CA, USA. The link is a plain hyperlink: no data is transmitted to Discord while you browse this site. We deliberately do not embed the Discord widget, which would contact Discord on every page load.

Only if you actively click the link do you leave this website. From that moment, Discord is the sole controller of any processing, under its own terms and privacy policy (see Discord Privacy Policy). Joining the server, creating an account and any data you post there are entirely between you and Discord; we receive no personal data from Discord and have no access to your account data. As server operators we can see the content you post in the server's channels and your Discord username.

Participation is entirely voluntary and is not required to use this website or to run a sensor device.

7. Server logs

When accessing the site, the hosting provider (IONOS SE, Montabaur, Germany) processes technical logs (e.g., IP address, timestamp, user agent) for security and troubleshooting. Logs are automatically purged after a short retention period.

7a. Visitor counting

We count page views to see how the site is used. This happens entirely on our server: no cookies are set, no script runs in your browser, and nothing is stored on your device. No third-party analytics service is involved and no data leaves our server.

Your IP address is not stored. To tell a repeat view apart from a new visitor within the same day, we compute a shortened one-way hash from your IP address and browser identification combined with a secret that changes every day. Because that secret rotates at midnight UTC, the same visitor cannot be recognised across days, and the hash can be neither reversed nor recomputed without it. These hashes are deleted after 7 days; what remains is a plain count per day and page, containing no personal data at all.

Alongside the count we record, aggregated per day and never per visit: which kind of client called (a person, an AI crawler, or another automated agent, and which one), the browser's language preference, a rough device class (desktop, mobile, tablet), which page was requested, and — only if our hosting provider supplies it as a server variable — a two-letter country code. We never query an external geolocation service, as that would mean sending your IP address to another company.

If you arrived through a link elsewhere, we store only the host of the referring site (for example discord.com), never the path or query string, because those routinely contain search terms or identifiers. Links from within this site are ignored. Country, language, device and referrer are recorded for human visitors only.

Recognisable automated requests (search engine crawlers, AI crawlers, link preview fetchers, monitoring) are identified by their self-declared user agent and counted separately from human visits. Legal basis: Article 6(1)(f) GDPR, our legitimate interest in understanding how the site is used. As no information is stored on or read from your device, section 25 TTDSG does not apply and no consent is required. You may object at any time under section 11.

8. Cookies & local storage

No third-party analytics, advertising, or social tracking. Our own page-view counting runs entirely on the server and is described in section 7a. We use the browser's local storage solely to remember your UI preferences (time range, refresh interval, cloud layer on/off), the dismissal of the data notice, and — if you chose so — your map consent (section 5). No profiling is performed and this data never leaves your browser.

9. Sharing

Apart from hosting by IONOS and the map tile delivery by Mapbox described above, data are not shared with third parties unless required by law.

10. Retention

Coarsened, published lightning datasets may be retained for research and statistics. Device telemetry is retained as long as the device participates in the network; participants can request deletion of their device's data at any time.

11. Your rights

Under the GDPR you have the rights of access, rectification, erasure, restriction, objection, and data portability regarding personal data (e.g., your device's telemetry). Contact us at info@hoong.de. You also have the right to lodge a complaint with a supervisory authority; the authority competent for us is the Saxon Data Protection Commissioner (Sächsische Datenschutz- und Transparenzbeauftragte, datenschutz.sachsen.de).

12. Updates

This notice may be updated to reflect legal or functional changes.