Position Fixing using short range high accuracy radio signals

Short-range high accuracy radio signals

can be used for hydrographic survey position fixing in a number of ways.

1. One common method is to use a differential global positioning system (DGPS). DGPS works by using a network of ground-based reference stations to correct the errors in GPS signals. This can improve the accuracy of GPS positioning to a few centimeters.

2. Another method of using short-range high accuracy radio signals for hydrographic survey position fixing is to use a real-time kinematic (RTK) GPS system. RTK GPS systems use a network of ground-based reference stations to provide centimeter-level positioning accuracy in real time. This is particularly useful for surveys of dynamic environments, such as tidal rivers and estuaries.

3. Local Positioning Systems (LPS) for hydrographic surveying. LPS systems use a network of radio transceivers to measure the distances between survey points. This information can then be used to calculate the positions of the survey points.LPS systems are often used in hydrographic surveys of coastal areas and harbors. They are particularly useful in areas where GPS signals are not available or are unreliable.

Here are some specific examples of how short-range high accuracy radio signals are used for hydrographic survey position fixing:

• DGPS is used to position survey vessels and other survey equipment, such as multibeam sonars and side scan sonars. This allows hydrographic surveyors to create accurate and detailed maps of the seabed.
• RTK GPS is used to position survey vessels and other survey equipment in real time. This is particularly useful for surveys of dynamic environments, such as tidal rivers and estuaries. For example, RTK GPS can be used to position a survey vessel while it is conducting a bathymetric survey of a tidal river.
• LPS is used to position survey vessels and other survey equipment in areas where GPS signals are not available or are unreliable. For example, LPS is often used to position survey vessels and other survey equipment in coastal areas and harbors, where GPS signals can be blocked by tall buildings and other structures.

Short-range high accuracy radio signals offer a number of advantages for hydrographic survey position fixing. They are accurate, reliable, and relatively inexpensive. They can also be used in a variety of environments.

However, it is important to note that short-range high accuracy radio signals have a limited range. This means that they are not suitable for surveys of large areas. Additionally, short-range high accuracy radio signals can be affected by interference from other radio signals and by atmospheric conditions.

Overall, short-range high accuracy radio signals are a valuable tool for hydrographic survey position fixing. They offer a number of advantages over other positioning methods, such as GPS. However, it is important to be aware of their limitations and to take steps to mitigate them.

Here are some additional details about the advantages and disadvantages of using short-range high accuracy radio signals for hydrographic survey position fixing:

Advantages:

• Accurate: Short-range high accuracy radio signals can provide centimeter-level positioning accuracy.
• Reliable: Short-range high accuracy radio signals are generally reliable and less susceptible to interference than GPS signals.
• Relatively inexpensive: Short-range high accuracy radio signal positioning systems are relatively inexpensive to purchase and maintain.
• Can be used in a variety of environments: Short-range high accuracy radio signal positioning systems can be used in a variety of environments, including coastal areas, harbors, and inland waterways.

Disadvantages:

• Limited range: Short-range high accuracy radio signals have a limited range, typically a few kilometers.
• Can be affected by interference: Short-range high accuracy radio signals can be affected by interference from other radio signals and by atmospheric conditions.

Hydrographic surveyors must carefully consider the advantages and disadvantages of short-range high accuracy radio signals before selecting a positioning system for their survey.