Create and use a List

gistfile1.cs

//creat a list of sprite objects
 List<Sprite> sprites=new List<Sprite>();

...


//populate a list of sprite objects
for (int i = 0; i < 50; i++)
            {
                Sprite s = new Sprite();
                s.SetRandomPosition(r,BattleFieldRect);
                s.SetRandomVelocity(r);
                sprites.Add(s);
            }

...

//draw all the lements in a list
spriteBatch.Begin(SpriteSortMode.Immediate, null, null, null, null, null, radarTrans);
foreach (Sprite s in sprites)
    s.Draw(gameTime, spriteBatch, true);
 spriteBatch.End();