05/04/2013

Reprojection: How to beat the system?

Landuse plan with WGS84 projection
Projected location is South of Lagos
Kedah cadaster map sits spots on Google Map
Cadaster map projection is copied. Note EPSG: 10005
EPSG 10005 parameters are then paste to Parameters box
Newly projected landuse plan now sits in alignment with cadaster map
Reprojection: Bagaimana nak mengatasi sistem?

Saya telah menguji teknik ni beberapa kali dengan kadaster negeri bersama peta gunatanah bagi sesuatu wilayah dan hasilnya berkesan. Kenapa nak susah-susah menentukan parameter bagi map projection parameters walhal apa yang penting adalah mendapatkan peta bagi kawasan kajian lalu mengalignkannya bersama peta Google. Bagi kes kadaster Kedah (EPSG:10005), dengan  Setting/Custom CRS, parameter berkaitan disalin dan ditiru kepada peta gunatanah. Apabila ianya telah disimpan dan diganti parameters asal kemudian di 'Zoom to Layer Extent', peta berkaitan akan melayang ke Kedah dan duduk tepat dengan lokasi yang sewajarnya. Mudahnya semua ni.

Reprojection: How to beat the system?

I've tested this technique so far for a number of state cadaster with landuse maps of a particular region and it works. Why crack your head coming up with the required map projection parameters when all it takes is find a cadaster map of the study area and ensure it aligns with Google Map. In the case of Kedah's cadaster (EPSG:10005), using the Setting/Custom CRS, the parameters were copied to the landuse map. Once saved replacing the original parameters then 'Zoom to Layer Extent', the map flew all the way to Kedah to sit perfectly where it ought to be. Life could not be simplier.

2 comments:

  1. Replies
    1. Not really. Like we experienced before, sometimes the answer is staring right in front of our face but we don't see it because we looked 'too close' and couldn't see the elephant because we only saw its trunk.

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