VOR?NDB?DME? totally confused

[flygirl04]

Right now I am trying to learn about VORs and NDBs and DMEs and i am completley confused...if anyone has an easy way to explain them...I would really appreciate it.

Well, I hate to say there's no easy answer. NDBs, VORs and DME are examples of ground-based navigation aids.

DME stands for Distance Measuring Equipment. It measures the slant range from you to the navigation aid. Slant range is the distance (in NM) as if you tied a string from the nav aid to the plane. It does not measure the distance over the ground. So the further you are away, the closer it is to the "over the ground" measurement. If you are at 6000 feet over the nav aid, the DME will read 1 nm! DME requires that you have equipment in your plane to receive and process the information. Actually, the unit sends and receives to calculate distance, speed and time.

DME is co-located with other ground-based nav aids such as VORs, ILSs and LOCs. DME operates in the UHF band.

VOR stands for Very high frequency Omnidirectional Range. These ground-based transmitters transmit radio beams (or radials) outward in every direction. The VOR system transmits two navigation signals. One is a reference signal which is constant all around the transmitter. The other is rotated at 1800 rpm. The receiver in your plane must measure the phase difference between these two. This allows you to determine which radial you are on.

NDB stands for Nondirectional Radio Beacon. It basically transmits similarly to an AM radio station. In fact, if you know the frequency of the AM station you can find the transmitter using your ADF (receiver in your aircraft) and listen to the ballgame. Basically, the NDB station broadcasts a signal and your receiver points to it. The nice thing about an NDB is that is does not require line of sight. Although many NDBs are very low power.

There's more to it than this. I just touched on the basics. There are plenty of books available on the subject of navigation. The one I like to recommend is Rod Machado's Private Pilot Handbook.
Any follow-up questions?