How do it know?

[Iceman07]

So I gets me a Garmin GPS396.

Logically, I can pretty much figure out how (on the panel page) the DG, the Altitude, the VS, but, how does (electronically) it figure out the Turn-and-Bank? In other words, how does the GPS know my angle of bank?

 

[CherryBomb]

It doesnt truly know. It compares your speed and your rate of turn and makes a rough estimate...

 

[avbug]

it figure out the Turn-and-Bank? In other words, how does the GPS know my angle of bank?

You understand that turn-and-slip indicators and turn-and-bank indicators and turn coordinators do NOT tell you anything about your angle of bank...only about your rate of turn. Right? (There's a reason that many instrument manufacturers put a statement right on the instrument face warning that the instrument (TBI/TC) that the instrument is not providing attitude information...it's strictly telling you about your rate of turn.

How does a GPS unit know how fast you're turning? The same way it knows how fast you're going, your eta, and your horiscope. Mathematics.

Except the horiscope.

 

[seethru]

We have the Garmin 296, which is basically the same as the 396 only in black and white (dang it, if we only waited like six months, we could have gotten the 396).

Anyway, I was pretty impressed with it's little virtual cockpit. As the owner flew the plane through some maneuvers I kept an eagle eye on the display from the 296 and compared it with what was indicating on my co-pilot instruments. Darned if they weren't dead on.

Now, I don't know how they do it, math or magic I imagine, but what a useful tool to have if the whole electrical system goes $hithou$e on you.

 

[Iceman07]

It doesnt truly know. It compares your speed and your rate of turn and makes a rough estimate...

Ah, OK, thanks. Now that you say it, it is one of those, "Oh, of course!" type things.

 

[Iceman07]

We have the Garmin 296, which is basically the same as the 396 only in black and white (dang it, if we only waited like six months, we could have gotten the 396).

Anyway, I was pretty impressed with it's little virtual cockpit. As the owner flew the plane through some maneuvers I kept an eagle eye on the display from the 296 and compared it with what was indicating on my co-pilot instruments. Darned if they weren't dead on.

Now, I don't know how they do it, math or magic I imagine, but what a useful tool to have if the whole electrical system goes $hithou$e on you.

Yup, I love my 396, but I am in the same boat, if I had waited 4 months, I could have had the 496.

In VFR, I tend to use the GPS as my primary, and the panel as back-up. Of course, most of my instruments are pretty crappy anyway (Strictly a VFR airplane), so....

 

[garf12]

didnt even know the 496 was out, whats differnt between it and the 396.

 

[Iceman07]

didnt even know the 496 was out, whats differnt between it and the 396.

Two things, as I understand it:

1) It has the USA Roads Database built in

2) It has the AOPA Airport guide built in.

So I get to wondering, it sounds like it's just a software upgrade, so why doesn't Garmin offer a software upgrade for the 396? Oh, wait, it's so they can sell more 496's.

 

[seethru]

Two things, as I understand it:

1) It has the USA Roads Database built in

2) It has the AOPA Airport guide built in.

So I get to wondering, it sounds like it's just a software upgrade, so why doesn't Garmin offer a software upgrade for the 396? Oh, wait, it's so they can sell more 496's.

Well, the 496 also adds XM Weather. If you have a Garmin's Mode S transponder, you can receive traffic as well.

I think it also has a more comprehensive terrain database.

 

[dseagrav]

The palm-based GPS I have does that too. It's really funny to carry it in a car and watch it work as I drive... This winter I plan to take it out with me while I do donuts in the parking lot. I bet that will get some interesting results.