This paper explores the feasibility of using celestial navigation as a backup or primary navigation system for drones. Researchers developed an algorithm that identifies stars in daytime images captured by a drone-mounted camera, using a star catalog and sun position information. By matching observed star positions with known celestial coordinates, the algorithm estimates the drone's attitude. Experimental results using real-world flight data demonstrated the system's ability to determine attitude with reasonable accuracy, suggesting potential for celestial navigation as a reliable, independent navigation solution for drones, particularly in GPS-denied environments.
This article details the creation of a custom star tracker for astronaut Don Pettit to capture stunning images of star trails and other celestial phenomena from the International Space Station (ISS). Engineer Jas Williams collaborated with Pettit to design a barn-door tracker that could withstand the ISS's unique environment and operate with Pettit's existing camera equipment. Key challenges included compensating for the ISS's rapid orbit, mitigating vibrations, and ensuring the device was safe and functional in zero gravity. The resulting tracker employed stepper motors, custom-machined parts, and open-source Arduino code, enabling Pettit to take breathtaking long-exposure photographs of the Earth and cosmos.
Hacker News users generally expressed admiration for Don Pettit's ingenuity and "hacker" spirit, highlighting his ability to create a functional star tracker with limited resources while aboard the ISS. Several commenters appreciated the detailed explanation of the design process and the challenges overcome, such as dealing with vibration and thermal variations. Some discussed the technical aspects, including the choice of sensors and the use of stepper motors. A few pointed out the irony of needing a custom-built star tracker on a space station supposedly packed with sophisticated equipment, reflecting on the limitations sometimes imposed by bureaucracy and pre-planned missions. Others reminisced about previous "MacGyver" moments in space exploration.
Summary of Comments ( 37 )
https://news.ycombinator.com/item?id=42767797
HN users discussed the practicality and novelty of the drone celestial navigation system described in the linked paper. Some questioned its robustness against cloud cover and the computational requirements for image processing on a drone. Others highlighted the potential for backup navigation in GPS-denied environments, particularly for military applications. Several commenters debated the actual novelty, pointing to existing star trackers and sextants used in maritime navigation, suggesting the drone implementation is more of an adaptation than a groundbreaking invention. The feasibility of achieving the claimed accuracy with the relatively small aperture of a drone-mounted camera was also a point of contention. Finally, there was discussion about alternative solutions like inertial navigation systems and the limitations of celestial navigation in certain environments, such as urban canyons.
The Hacker News post titled "Celestial Navigation for Drones" links to a scientific paper detailing a method for drone navigation using celestial positioning. The comments section contains a moderate amount of discussion, primarily focusing on the practicality and limitations of the proposed method.
Several commenters express skepticism about the real-world applicability of celestial navigation for drones, especially given the existing reliability and affordability of GPS. One commenter points out that GPS jamming and spoofing are already significant concerns, and while celestial navigation might offer a backup in these scenarios, the required clear sky conditions would often be unavailable precisely when such countermeasures are being employed. They also question the precision achievable with this method compared to GPS, particularly for small drones where minor positional errors could be significant.
Another commenter highlights the computational complexity of celestial navigation, suggesting it would require significant processing power on the drone, potentially impacting battery life and payload capacity. They also mention the need for an extremely accurate clock, which adds further complexity and cost.
A more supportive comment acknowledges the limitations but suggests the method could be valuable for specific niche applications where GPS is unavailable or unreliable, such as high-altitude or polar regions. They also propose a hybrid approach combining celestial navigation with other positioning systems for increased robustness.
Some commenters discuss the potential benefits of using celestial navigation for security and resilience, arguing that it provides an independent and difficult-to-spoof navigation method. However, others counter that the vulnerability to cloud cover makes it less reliable in critical situations.
One commenter raises the issue of light pollution, suggesting it could interfere with celestial navigation in urban environments. Another user mentions the potential for using a database of star positions to simplify the calculations, reducing the computational burden on the drone.
A few commenters express interest in the historical context of celestial navigation and its potential resurgence in modern technology. They see the research as an interesting exploration of alternative navigation techniques, even if the practical applications are limited.
Overall, the comments reflect a mixed reception to the idea of celestial navigation for drones. While some see potential in specific niche applications, many remain skeptical about its widespread adoption due to the limitations and challenges compared to existing GPS technology. The discussion highlights the trade-offs between resilience, accuracy, complexity, and cost associated with different navigation methods.