Jeff Geerling's blog post highlights Beidou Position System (BPS), China's independently developed global navigation satellite system, as a lesser-known alternative to GPS. He details its development, global coverage, and increasing accuracy, emphasizing its potential as a backup or even primary navigation system, particularly for those needing to operate independently of US-controlled infrastructure. Geerling shares his experience testing BPS receivers, noting its comparable performance to GPS in his basic experiments and the growing availability of BPS-compatible devices. He concludes by advocating for greater awareness of BPS as a viable option in the GNSS landscape.
The article "Overengineered Anchor Links" explores excessively complex methods for implementing smooth scrolling anchor links, ultimately advocating for a simple, standards-compliant approach. It dissects common overengineered solutions, highlighting their drawbacks like unnecessary JavaScript dependencies, performance issues, and accessibility concerns. The author demonstrates how a concise snippet of JavaScript leveraging native browser behavior can achieve smooth scrolling with minimal code and maximum compatibility, emphasizing the importance of prioritizing simplicity and web standards over convoluted solutions. This approach relies on Element.scrollIntoView() with the behavior: 'smooth' option, providing a performant and accessible experience without the bloat of external libraries or complex calculations.
Hacker News users generally agreed that the author of the article overengineered the anchor link solution. Many commenters suggested simpler, more standard approaches using just HTML and CSS, pointing out that JavaScript adds unnecessary complexity for such a basic feature. Some appreciated the author's exploration of the problem, but ultimately felt the final solution was impractical for real-world use. A few users debated the merits of using the <details> element for navigation, and whether it offered sufficient accessibility. Several comments also highlighted the performance implications of excessive JavaScript and the importance of considering Core Web Vitals. One commenter even linked to a much simpler CodePen example achieving a similar effect. Overall, the consensus was that while the author's technical skills were evident, a simpler, more conventional approach would have been preferable.
GPS jamming and spoofing are increasing threats to aircraft navigation, with potentially dangerous consequences. A new type of atomic clock, much smaller and cheaper than existing ones, could provide a highly accurate backup navigation system, independent of vulnerable satellite signals. These chip-scale atomic clocks (CSACs), while not yet widespread, could be integrated into aircraft systems to maintain precise positioning and timing even when GPS signals are lost or compromised, significantly improving safety and resilience.
HN commenters discuss the plausibility and implications of GPS spoofing for aircraft. Several express skepticism that widespread, malicious spoofing is occurring, suggesting alternative explanations for reported incidents like multipath interference or pilot error. Some point out that reliance on GPS varies among aircraft and that existing systems can mitigate spoofing risks. The potential vulnerabilities of GPS are acknowledged, and the proposed atomic clock solution is discussed, with some questioning its cost-effectiveness and complexity compared to other mitigation strategies. Others suggest that focusing on improving the resilience of GPS itself might be a better approach. The possibility of state-sponsored spoofing is also raised, particularly in conflict zones.
Polish researchers suspect that GPS jamming in the Baltic Sea, affecting maritime and air navigation, is being deliberately caused by ships, possibly linked to the ongoing war in Ukraine. The Centre for Eastern Studies (OSW) report highlights numerous incidents of interference, particularly near Russian naval exercises and around strategic areas like the Bornholm Basin, suggesting a potential Russian military strategy to disrupt navigation and create uncertainty. While technical malfunctions are possible, the patterns of interference strongly point toward intentional jamming, impacting both civilian and military operations in the region.
Several Hacker News commenters discuss the plausibility and implications of GPS jamming in the Baltic Sea. Some express skepticism, suggesting the observed disruptions could be caused by unintentional interference or even solar flares. Others point out the increasing availability and use of GPS jammers, highlighting their potential use in smuggling or other illicit activities. The prevalence of spoofing is also raised, with one commenter mentioning the known use of GPS spoofing by Russia around airports and other strategic locations. Another commenter questions the motivation behind such jamming, speculating that it could be related to the ongoing war in Ukraine, possibly to mask ship movements or disrupt navigation. A few comments also touch on the broader implications for maritime safety and the potential for escalating tensions in the region.
NASA has successfully demonstrated the ability to receive GPS signals at the Moon, a first for navigating beyond Earth’s orbit. The Navigation Doppler Lidar for Space (NDLS) experiment aboard the Lunar Reconnaissance Orbiter (LRO) locked onto GPS signals and determined LRO’s position, paving the way for more reliable and autonomous navigation for future lunar missions. This achievement reduces reliance on Earth-based tracking and allows spacecraft to more accurately pinpoint their location, enabling more efficient and flexible operations in lunar orbit and beyond.
Several commenters on Hacker News expressed skepticism about the value of this achievement, questioning the practical applications and cost-effectiveness of using GPS around the Moon. Some suggested alternative navigation methods, such as star trackers or inertial systems, might be more suitable. Others pointed out the limitations of GPS accuracy at such distances, especially given the moon's unique gravitational environment. A few commenters highlighted the potential benefits, including simplified navigation for lunar missions and improved understanding of GPS signal behavior in extreme environments. Some debated the reasons behind NASA's pursuit of this technology, speculating about potential future applications like lunar infrastructure development or deep space navigation. There was also discussion about the technical challenges involved in acquiring and processing weak GPS signals at such a distance.
Shunpo is a minimalist Bash tool designed to streamline directory navigation. It learns frequently visited directories and allows users to quickly jump to them using short, custom aliases. By storing these aliases and their corresponding paths in a simple text file, Shunpo avoids complex databases and remains lightweight and portable. It offers basic commands for adding, removing, listing, and navigating to saved locations, simplifying the process of moving between commonly accessed folders within the terminal.
Hacker News users discussed Shunpo's utility and potential drawbacks. Some found its core functionality—quickly jumping to frequently used directories—appealing, especially combined with tools like fzf. Others questioned its value proposition over existing solutions like autojump, z, or fasd, particularly given its reliance on find. Concerns were raised about performance in large directory trees and the security implications of executing arbitrary commands generated from find results. Some suggested improvements, including leveraging shell builtins for better performance and integrating more advanced selection mechanisms. The project's minimalism was both praised and criticized, with some appreciating its simplicity and others desiring more features like directory tracking or the ability to ignore certain paths.
SimpleSearch is a website that aggregates a large directory of specialized search engines, presented as a straightforward, uncluttered list. It aims to provide a quick access point for users to find information across various domains, from academic resources and code repositories to specific file types and social media platforms. Rather than relying on a single, general-purpose search engine, SimpleSearch offers a curated collection of tools tailored to different search needs.
HN users generally praised SimpleSearch for its clean design and utility, particularly for its quick access to various specialized search engines. Several commenters suggested additions, including academic search engines like BASE and PubMed, code-specific search like Sourcegraph, and visual search tools like Google Images. Some discussed the benefits of curated lists versus relying on browser search engines, with a few noting the project's similarity to existing search aggregators. The creator responded to several suggestions and expressed interest in incorporating user feedback. A minor point of contention arose regarding the inclusion of Google, but overall the reception was positive, with many appreciating the simplicity and convenience offered by the site.
The blog post argues that file systems, particularly hierarchical ones, are a form of hypermedia that predates the web. It highlights how directories act like web pages, containing links (files and subdirectories) that can lead to other content or executable programs. This linking structure, combined with metadata like file types and modification dates, allows for navigation and information retrieval similar to browsing the web. The post further suggests that the web's hypermedia capabilities essentially replicate and expand upon the fundamental principles already present in file systems, emphasizing a deeper connection between these two technologies than commonly recognized.
Hacker News users largely praised the article for its clear explanation of file systems as a foundational hypermedia system. Several commenters highlighted the elegance and simplicity of this concept, often overlooked in the modern web's complexity. Some discussed the potential of leveraging file system principles for improved web experiences, like decentralized systems or simpler content management. A few pointed out limitations, such as the lack of inherent versioning in basic file systems and the challenges of metadata handling. The discussion also touched on related concepts like Plan 9 and the semantic web, contrasting their approaches to linking and information organization with the basic file system model. Several users reminisced about early computing experiences and the directness of navigating files and folders, suggesting a potential return to such simplicity.
Researchers have demonstrated a method for using smartphones' GPS receivers to map disturbances in the Earth's ionosphere. By analyzing data from a dense network of GPS-equipped phones during a solar storm, they successfully imaged ionospheric variations and travelling ionospheric disturbances (TIDs), particularly over San Francisco. This crowdsourced approach, leveraging the ubiquitous nature of smartphones, offers a cost-effective and globally distributed sensor network for monitoring space weather events and improving the accuracy of ionospheric models, which are crucial for technologies like navigation and communication.
HN users discuss the potential impact and feasibility of using smartphones to map the ionosphere. Some express skepticism about the accuracy and coverage achievable with consumer-grade hardware, particularly regarding the ability to measure electron density effectively. Others are more optimistic, highlighting the potential for a vast, distributed sensor network, particularly for studying transient ionospheric phenomena and improving GPS accuracy. Concerns about battery drain and data usage are raised, along with questions about the calibration and validation of the smartphone measurements. The discussion also touches on the technical challenges of separating ionospheric effects from other signal variations and the need for robust signal processing techniques. Several commenters express interest in participating in such a project, while others point to existing research in this area, including the use of software-defined radios.
Summary of Comments ( 111 )
https://news.ycombinator.com/item?id=43669308
HN commenters discuss the viability and practicality of BPS, noting it's largely theoretical and faces significant hurdles. Several point out the immense infrastructure investment required for terrestrial positioning systems like BPS, especially compared to the established satellite-based GPS. Some question the accuracy claims and highlight potential interference issues in dense urban environments. Others express skepticism about BPS's resistance to jamming and spoofing, crucial for critical infrastructure. A few comments mention Loran-C as a more mature terrestrial alternative, although it has its limitations. Overall, there's a consensus that while intriguing, BPS lacks the development and backing to become a serious competitor to GPS in the foreseeable future.
The Hacker News comments section for the post "BPS is a GPS alternative that nobody's heard of" (linking to Jeff Geerling's blog post about Beidou Position System) contains a robust discussion with various perspectives on the viability and implications of BPS.
Several commenters point out that BPS isn't exactly "nobody's heard of," particularly outside the US. Some users from Asian countries mention its widespread adoption in their regions for various applications, including ride-hailing services and personal navigation. They highlight that phones and devices often support both GPS and BPS concurrently, leading to improved accuracy and availability, especially in urban areas with potential GPS signal obstruction.
A recurring theme in the comments is the geopolitical aspect of BPS. Commenters discuss its role as a strategic alternative to the US-controlled GPS, offering nations more independence and potentially reducing reliance on American infrastructure. Some express concerns about the potential for data privacy issues and government surveillance with a system controlled by China. This leads to a discussion about the trade-offs between national security concerns and technological benefits.
Technical details of BPS are also discussed, with commenters mentioning its dual-frequency civilian signal and comparing its accuracy and coverage to GPS. Some users share their personal experiences using devices with BPS support, noting its performance in different environments. There's also a discussion about the integration of BPS into various devices and software platforms, with some commenters pointing out challenges in its adoption outside of China due to existing GPS infrastructure and industry standards.
The concept of combining multiple satellite navigation systems (GNSS) like GPS, BPS, Galileo, and GLONASS is brought up, with commenters emphasizing the benefits of increased accuracy and resilience by leveraging multiple constellations. This leads to a discussion of the future of global navigation and the potential for a more multi-polar system with less reliance on any single provider.
Finally, several comments focus on the blog post itself, with some users critiquing the author's characterization of BPS as "unknown" and suggesting that the title is misleading. Others appreciate the introduction to BPS and the subsequent discussion it generated. The comment section, overall, provides valuable insights into the current state and future potential of BPS, going beyond the initial premise of the blog post.