Construction of a square grid from a given centre (lat,lon) and direction of the sides

Let us consider a point (longitude, latitude) on Earth (location).

How to construct a square grid around this point (taking this point as the centre of the square or intercept of the two diagonals) with size of the square as 0.1 degree times 0.1 degree and direction of the one side of square is theta degree?

For example, let the sample point to be (88.38045, 21.04247) and theta = 70 degree. Here is a rough plot for clarification. Note: This direction is computed from the 84 E meridian.

• In fact Lat Long is a spherical coordinate system. So By the Theta you relate to a deflection angle to one plane what about other plane.... – SIslam Jan 30 '15 at 13:56
• @msi_g Thanks for attention. you are right, its a deep observations, i have not think about that. Here what I want is that: after plotting the (lat,lon) point in 2d, draw square around it in that direction. – Janak Jan 30 '15 at 14:03
• Ok.if it is on 2d(e.g.UTM45 for Bay of Bengal-offshore of West Bengal) then what will be the X axis and what will be Y, because there are several X(meridians) and Y(parallels) then wherefron you will measure theta? – SIslam Jan 30 '15 at 14:15
• @msi_g I am working with data, only in the latitude range (21-25) and longitude (84-88). Data are satellite observations in this region. I can get direction of the square from the passing direction of the satellite. This theta is measured from the meridian of 84 degree east (the minimum lat). – Janak Jan 30 '15 at 14:32 