Antenna Debug Example

Now that you've read the guide on the Antenna debugger, here are a few situations in which it can come in handy.

Example 1

My probe is in orbit of Venus. The antenna planner said I should have a connection, but I don't.

What's wrong here? (click for answer)

Answer: Antenna elevation is only 2.3 degrees! This results in a fairly high atmosphere noise of 49K. This, in turn, raises N0, which means our Eb/N0 is less than one and we are unable to establish a connection. Wait for the probe and/or earth to move so the ground station doesn't have to look so close to the horizon, and a connection is established at around 22 degrees of elevation.

Example 2

I sent a probe to the moon, and now it doesn't have a connection.

What's wrong here? (click for answer)

Answer: Everything looks fine here. Atmosphere and body noise are very low, and there are no pointing losses. Ultimately, this antenna just doesn't have enough power to transmit from the moon to the Earth. Received power is extremely low at DSNTrackingStation.

Example 3

My probe is in orbit or Mars. The antenna planner said I should have a connection, but now I don't have one and the antenna debug window is blank

What's wrong here? (click for answer)

Answer: If the Antenna debug window is blank, it means it can't find any antennas with a line-of-sight to your antenna. A celestial body is between you and the Earth, blocking your connection. It could be Mars, Deimos, Phobos, the Moon, or even the Sun. Just wait a few hours, and whatever is in your way should move.

Example 4

I made a relay satellite, but my other craft won't connect to it

What's wrong here? (click for answer)

Answer: The receiving antenna has an AoA of 175.8 degrees, but only has a 3-dB beamwidth of 6.97 degrees. It's pointing almost directly away from the relay satellite, and as can be seen in the losses menu, is taking 200 dB of pointing losses because it's not pointed at the relay. Since the Eb/N0 is -191.5 dB, and the pointing losses are 200 dB, you should be able to achieve an Eb/N0 of 8.5 dB once the pointing issue is resolved and establish a connection.