PELAYARAN DATAR ‼️ PERHITUNGAN HALUAN JAUH ‼️ [haluan Timur Barat] part 1

Summary

This video script covers the calculation of bearing and distance (Simpang) in nautical navigation using east-west bearings. It explains how to determine the change in longitude (Delta bujur) and convert it into Simpang using a navigational guidebook (daftar tiga). The tutorial provides an example where a ship's longitude changes, but its latitude remains constant, demonstrating how to compute the distance and bearing (East or West) accurately. The method emphasizes the importance of understanding Delta bujur and using the proper chart for conversion, ultimately helping users calculate the ship's journey accurately.

Takeaways

• 😀 The script focuses on teaching the calculation of bearings and distances using both north-south and east-west directions.
• 😀 Bearings in the east-west direction are based on changes in longitude, whereas north-south bearings are based on latitude.
• 😀 The concept of 'Simpang' is introduced, which refers to the distance traveled along the east-west direction and is not the same as direct distance.
• 😀 In the east-west direction, changes in longitude (Delta longitude) do not directly equal the distance traveled, unlike the north-south direction.
• 😀 Delta longitude (change in longitude) is calculated, and it needs to be converted to 'Simpang' (nautical miles) using the appropriate tables from navigation textbooks.
• 😀 The concept of 'Simpang' is distinct from direct distance, requiring conversion using specific navigational references (like the S3 navigation table).
• 😀 The latitude (or Lintang) does not change in the east-west direction when moving along a constant latitude, but longitude (Bujur) will change.
• 😀 The process of calculating the distance using Delta longitude involves determining the difference between two longitudes and using navigation charts for conversion.
• 😀 An example was provided where a ship's coordinates changed only in longitude (not latitude), showing the calculation process of converting Delta longitude into Simpang.
• 😀 The script encourages students to familiarize themselves with the S3 navigation table and practice calculating the Simpang before proceeding with further exercises.

Q & A

What is the main focus of this navigation lesson?

The main focus is on calculating bearings and distances (referred to as 'Simpang') along the east-west direction, based on changes in longitude, and how to use reference tables to determine the corresponding distance.

How is the bearing for east and west directions calculated?

The bearing for east is 90°, while for west it is 270°. Bearings are determined by the direction of movement along lines of longitude.

What does 'Simpang' refer to in the context of navigation?

'Simpang' refers to the distance traveled along the east-west direction, which is not directly the change in longitude but needs to be calculated using specific formulas or navigation reference tables.

Why is Delta longitude not directly equal to the distance traveled?

Delta longitude (the change in longitude) does not directly equal the distance traveled because the distance must be calculated using a reference table ('daftar tiga ilmu pelayaran') which accounts for the curvature of the Earth and other factors.

What steps should be followed to calculate the distance traveled (Simpang)?

First, calculate the Delta longitude (difference in longitude). Then, convert the Delta longitude into minutes. Finally, use the reference table to convert the minutes into Simpang (distance).

Can you provide an example of calculating the distance (Simpang)?

In the example, the ship moves from 2°13' E to 2°13' E, with a change in longitude from 97°35' to 97°58'. The distance (Simpang) calculated using the reference table is 80.443 nautical miles.

What is the significance of the 'daftar tiga ilmu pelayaran' table in this process?

The 'daftar tiga ilmu pelayaran' table is crucial for converting Delta longitude (in minutes) into Simpang (distance) by providing specific values based on the latitude and longitude changes.

What happens when the longitude increases during the calculation?

If the longitude increases, the bearing is to the east (haluan timur). Conversely, if the longitude decreases, the bearing is to the west (haluan barat).

What does the instructor recommend for better understanding?

The instructor recommends practicing using the reference table ('daftar tiga ilmu pelayaran') and performing exercises to better understand the concepts and calculations.

How does the instructor explain the direction of the bearing in relation to longitude changes?

The instructor explains that the direction of the bearing depends on the relative change in longitude. If the longitude increases (e.g., from 97° to 98°), the bearing is east. If it decreases (e.g., from 98° to 97°), the bearing is west.