Project ideas from Hacker News discussions.

Show HN: Algorithmically finding the longest line of sight on Earth

📝 Discussion Summary (Click to expand)

1. Accuracy & algorithmic detail
The community is deeply engaged in how the line‑of‑sight (LOS) algorithm works, what data it uses, and how close the results are to reality.
- “The error I've experienced hunting bugs tends to be within about .5‑2%.” – mrb
- “The algorithm is already fairly expensive to run against the whole world so we weren't particularly interested in that level of coverage for the full earth.” – tombh
- “I think it would also really help if the maps themselves were at an angle in 3D with an exaggerated relief, with the line drawn in 3D, so you can get a sense of how it travels between two peaks.” – crazygringo

2. Real‑world validation & record attempts
Users discuss actual photographs, radio contacts, and world‑record claims that test the LOS model.
- “The longest and second longest haven't been photographed yet, but #3 has.” – tombh
- “I just made a 1.2 GHz FM contact 244 km away from the summit of a 14er to the summit of another 14er.” – stilldavid
- “The record was actually recently beaten … 11 % further is quite a increase and not far from the maximum possible.” – sllabres

3. Community interest & future extensions
Participants want richer visualisations, easier access, and new use‑cases for the data.
- “I would love to see photos” – hybrid_study
- “I think it would also really help if the maps themselves were at an angle in 3D …” – crazygringo
- “I would love to see photos” – justjash (and many others)

These three themes—technical rigor, real‑world testing, and user‑driven feature requests—drive the discussion.


🚀 Project Ideas

Sightline 3D Explorer

Summary

  • Interactive web app that renders 3‑D line‑of‑sight between any two points, automatically generating Google Earth/Cesium links and overlaying the computed path on a realistic terrain model.
  • Adds a photo‑gallery feature that pulls images from Flickr, Instagram, and user uploads for the exact sightline, giving users a visual confirmation of the view.

Details

Key Value
Target Audience Outdoor enthusiasts, photographers, ham radio operators, GIS hobbyists
Core Feature 3‑D line‑of‑sight rendering + auto‑generated Earth view links + photo matching
Tech Stack React + Three.js, CesiumJS, Node.js backend, PostgreSQL/PostGIS, Flickr/Instagram APIs
Difficulty Medium
Monetization Revenue‑ready: freemium (free core, $5/month for premium photo library and advanced refraction models)

Notes

  • Users complained: “I want to see a photo! Or at least what it looks like in Google Earth” (crazygringo).
  • The tool would satisfy the “longest line of sight” curiosity and provide the “side view” that many commenters asked for.
  • The 3‑D view solves the frustration of “the line drawn on a 2‑D map” and gives a realistic sense of distance.

QGIS Viewshed Pro

Summary

  • A QGIS plugin that exposes the full line‑of‑sight algorithm, allowing users to compute viewsheds, longest sightlines, and multi‑directional visibility from any point, with support for high‑resolution LiDAR and building‑height data.
  • Includes a “view‑by‑direction” panel that lists the top N visible points and their distances.

Details

Key Value
Target Audience GIS professionals, surveyors, environmental planners, hobbyists
Core Feature Full viewshed & longest‑line computation, multi‑directional output, high‑res data support
Tech Stack Python (PyQGIS), GDAL/OGR, NumPy, PostGIS, optional C++ extension for speed
Difficulty High
Monetization Revenue‑ready: $99 one‑time license or $9/month subscription for cloud‑based processing

Notes

  • Commenters noted: “I want to see a photo… or at least what it looks like in Google Earth” and “I want to see the 3‑D rendering” (crazygringo, stevage).
  • The plugin addresses the need for “higher resolution data” and “integration with GIS” (hdersch, whiteCaps).
  • It also solves the “multiple views per point” frustration (em-bee, tombh).

Sightline Photo Match

Summary

  • A community‑driven web service that aggregates user‑submitted photos of long sightlines, matches them to computed line‑of‑sight data, and displays a gallery of verified views for each pair of points.
  • Provides a “photo‑verified” badge for the longest sightlines and allows users to upload new images for validation.

Details

Key Value
Target Audience Photographers, mountaineers, ham radio enthusiasts, geography hobbyists
Core Feature Photo matching, verification workflow, gallery per sightline, API for external use
Tech Stack Django, Celery, OpenCV for image matching, PostgreSQL/PostGIS, AWS S3 for storage
Difficulty Medium
Monetization Hobby (open source) with optional paid API access for commercial use

Notes

  • Many commenters expressed a desire for photos: “I want to see a photo!” (crazygringo, 12ian34).
  • The service would provide the “practical utility” of confirming that a sightline is real, addressing the “photo‑matching” pain point.
  • It encourages community engagement and could become a go‑to resource for record‑keeping and storytelling.

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