In Malaysia, there are 3 types of datum.
First, prove 3 boundary marks in position with comparison old & new value either by straight observation or traverse method. The angle and distance must within the limitation.
Theoretically, the angle should within 10” as stated in survey regulation 2002. However, in some cases where the previous survey was second class value then angle limitation is allowed to 30”.
For your information, second class has been ceased and all the survey must be in first class value at the moment. The tolerance distance is 50mm and below. This figure is not stated in survey regulation 2002 but it is from our survey experience. 50mm is just a benchmark and in survey regulation 2002 or 1976, it clearly stated that any displacement in town survey is allowed to 50mm and no re-fixation can be carried for that particular marks.
Secondly, two boundary marks in position and one astronomy observation as azimuth. Usually these 2 boundary marks distance must be more than 30 m. While the astronomy observation is do comparison on bearing for that particular line. In Peninsular Malaysia, we are lucky because nearly everyday we are able to see sun unless the weather is rain. Thus, we seldom or never do star observation. If you ask me then I need to seek from my lecture notes.
Thirdly is by GPS method and no many licensed land surveyor in Peninsular Malaysia implemented the system. One of them is me…..J
This is my general view regarding Malaysia datum.
Basically, I used to start with sun observation when I found the location. Many people especially the land owner will ask me why I chase for sun. Then I will tell them, sun is my natural GPS which I do not need to buy. They will laugh and joke with me.
First, prove 3 boundary marks in position with comparison old & new value either by straight observation or traverse method. The angle and distance must within the limitation.
Theoretically, the angle should within 10” as stated in survey regulation 2002. However, in some cases where the previous survey was second class value then angle limitation is allowed to 30”.
For your information, second class has been ceased and all the survey must be in first class value at the moment. The tolerance distance is 50mm and below. This figure is not stated in survey regulation 2002 but it is from our survey experience. 50mm is just a benchmark and in survey regulation 2002 or 1976, it clearly stated that any displacement in town survey is allowed to 50mm and no re-fixation can be carried for that particular marks.
Secondly, two boundary marks in position and one astronomy observation as azimuth. Usually these 2 boundary marks distance must be more than 30 m. While the astronomy observation is do comparison on bearing for that particular line. In Peninsular Malaysia, we are lucky because nearly everyday we are able to see sun unless the weather is rain. Thus, we seldom or never do star observation. If you ask me then I need to seek from my lecture notes.
Thirdly is by GPS method and no many licensed land surveyor in Peninsular Malaysia implemented the system. One of them is me…..J
This is my general view regarding Malaysia datum.
Basically, I used to start with sun observation when I found the location. Many people especially the land owner will ask me why I chase for sun. Then I will tell them, sun is my natural GPS which I do not need to buy. They will laugh and joke with me.
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