CODEWITHSUNDEEP
locationlatitude-longitude
Shashank.Kr
Shashank.Kr

Reputation: 77

Location Based Applications : Longitude and Latitude values

I am working on indexing for multidimensional objects (location based services: long/lat/time for eg.) and experimenting with hilbert curve. The problem is, the java code i have works good upto 64 bits. For example:

value ( long, lat, time ) = H(bits)

if the number of bits > 64 , the algo fails.

So i just need to know what is the feasible range of long and lat values should i consider for real world applications?? Is it : -180 to 180 for longitude and 90 to -90 for latitude??

Thanks

Upvotes: 0

Views: 364

Answers (1)

aleph_null
aleph_null

Reputation: 5786

Yeah, it is typical to define longitude to be between -180 and 180 and latitude between -90 and 90 as you said. I have seen the range 0 to 360 for longitude, but no where near as often.

What's important is that you define latitude across a range of 360 degrees and latitude across a range of 180, since that lets you find any point on the earth.

Although I am completely ignorant of hilbert curves and don't know what's involved in your task, I would recommend making sure that you understand that the values of latitude and longitude typically used are geodetic. Latitude is thus the angle that a line normal to the surface of the earth makes against the equatorial plane. This line will not go through the center of the earth unless you are on the equator.

Upvotes: 1

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