Find nearest object query with LINQ

While LINQ simplifies your DAL in myriad ways, this seemingly simple query made me stop and think about how to properly explain this to the query engine

Problem: Given an input of a current location (latitude and longitude) find all objects in the database within a specified radius

Disclaimer: This is using a bounding box hack rather than an accurate radius forumula, use at your own risk as there is some loss of precision.

     /// Find all courts within a specified radius (in miles) to a point (latitude & longitude)
     /// <param name="latitude">degrees(decimal)</param>
     /// <param name="longitude">degrees(decimal)</param>
     /// <param name="radius">miles</param>
     /// <returns></returns>
     public IQueryable<Court> FindNearbyCourts(decimal latitude, decimal longitude, decimal radius);

The first order of business is to convert miles to degrees of latitude and longitude, respectively.

     decimal radiusLatitude = radius / 69.04;
     decimal radiusLongitude = radius / 59.96;

Once we have these conversions in place, we are ready to build our LINQ query:

     IQueryable<Court> nearbyCourts = from court in _db.Courts 
          where (Math.Abs(court.latitude - latitude) < radiusLatitude) 
          where (Math.Abs(court.longitude - longitude) < radiusLongitude) 
               select court;

Return the IQueryable object nearbyCourts you just generated and you're all set.