We know the way: learning the secrets of celestial navigation from ancient travellers

Educators are constantly looking for new ways to inspire students to actively engage with science. Learning how to navigate by using the stars, sun and moon can be one of the first steps for pupils, students and the general public to cultivate an interest in astronomy. With this in mind, an online platform based on the Google Earth and Stellarium software has been developed. It presents basic celestial navigation techniques that were first devised and deployed by the ancient Phoenicians and Greeks, the Vikings and the Polynesian travellers. Both software applications are free to use and are available in web versions, making them easily accessible to anyone with an internet connection. The user undertakes a set of predefined tasks that take him/her on a fascinating journey both around the world and back in time.

Adaptively robust filtering algorithm for maritime celestial navigation

Celestial navigation is an important means of maritime navigation; it can automatically achieve inertially referenced positioning and orientation after a long period of development. However, the impact of different accuracy of observations and the influence of nonstationary states, such as ship speed change and steering, are not taken into account in existing algorithms. To solve this problem, this paper proposes an adaptively robust maritime celestial navigation algorithm, in which each observation value is given an equivalent weight according to the robust estimation theory, and the dynamic balance between astronomical observation and prediction values of vessel motion is adjusted by applying the adaptive factor. With this system, compared with the frequently used least square method and extended Kalman filter algorithm, not only are the real-time and high-precision navigation parameters, such as position, course, and speed for the vessel, calculated simultaneously, but also the influence of abnormal observation and vessel motion status change could be well suppressed.

Akurasi Nilai Tinggi Matahari Antara Perhitungan Daftar Ilmu Pelayaran (DIP) Dan Sight Reduction Table (SRT)

Positioning with celestial bodies (celestial navigation) is the art of determining on the surface of the earth based on measurements of celestial bodies which have guided sailors for hundreds of years. Astronomical positioning methods or celestial body navigation are becoming increasingly obsolete and rarely used. The fact is that today, along with technological advances, seafarers prefer to use electronic navigation tools such as the Global Positioning System (GPS). The the International Convention on Standard of Training, Certification and Watchkeeping for Seafarers (STCW) amended 2011, requires all officers on board responsible for navigation to be able to determine the height of celestial bodies, the Line of Position (LOP) and the position of the ship. In general, there are 2 methods of determining the navigation position of celestial bodies, namely by calculating the Sight Reduction Table. This research discusses the accuracy of determining the height of the solar count by comparing the accuracy of the 2 methods. The method used is descriptive comparative based on field research with a qualitative approach. The technique of collecting data was done by means of observation, documentation and literature study. The purpose of this research is to test the accuracy of each calculation method, namely the calculation of the Sailing List (DIP) and the Sight Reduction Table (SRT). The results obtained in this study are the high calculation accuracy calculation method of calculating shipping science lists is more accurate with testing which is further discussed in this study.

Testing the Functionality and Applicability of Smart Devices for a Handheld Celestial Navigation System

In this paper, the functionality and applicability of smart devices for the purpose of handheld celestial navigation systems is investigated. The main instrument used to determine observer position (altitude measurements) in celestial navigation is the sextant. The use of a sextant and almanac or computer is a classical approach to determining the observer's celestial position. This approach has two significant limitations, firstly the time window for the measurements is short, and secondly, the view of the ocean horizon must be clear. With the use of smart devices, we can overcome these two obstacles and create a so-called handheld celestial navigation system. Currently, smart devices have very accurate sensors to measure various physical quantities such as acceleration, angular velocity, orientation, etc. We are particularly interested in validating the orientation sensor for measuring the altitude and azimuth of the celestial body. The altitude of the celestial body is the primary parameter in determining the celestial position using a sextant. The idea is to replace the sextant with a smart device to measure the altitude and possibly the azimuth of the celestial body. To test this idea, two types of experiments are designed. In the first, a system on a tripod to obtain the most accurate measurements possible is set. Such tests will provide detailed information about the accuracy of the smart device's sensors and its applicability in measuring altitude and azimuth. The test system will essentially resemble a theodolite device. In the second experiment, a hands-free measurement experiment that resembles a sextant to test the idea for practical use and functionality in the process of celestial positioning is set. The observed data show that the results of the measurements under controlled conditions are promising and within reasonable bounds for the accuracy of celestial positioning. Estimates of the position error by the graphical method are in the range of 10 Nm to 30 Nm. In order to obtain a fully functional stand-alone celestial positioning system, the proposed assembly needs to be improved through several unchallenging upgrades. A fully functional system can be considered as a cheap off-the-shelf handheld Celestial Navigational System (CNS).