Consistency Level

[Jim Frame]

I'm a little confused about the Consistency Level setting in RTK Verify. In the T-LS Users Guide, this setting is mentioned in only 2 places: on page 139 with a basic explanation of its response, and on page 142 with suggested setting values. I'm running with V6 Reset enabled, and the Consistency Level setting is grayed out:

I gather that since the Consistency Counter only pertains when engines aren't reset, and that it doesn't pertain to V6 Reset conditions. So is it's purpose simply to give the user an indication -- when resets aren't being imposed -- of the number of engines fixed during the time span of the observation?

 

[Matt Johnson]

The Consistency Level is used both with and without verify with resets when "How to Stop" is set to After n epochs. You are probably seeing it grayed out because you have "How to Stop" set to "Stop Button" or "When Titled".

 

[Jim Frame]

Is it only used with stop-after-n-epochs settings? Does it override n if the consistency setting isn't met after n epochs?

 

[Matt Johnson]

This is the How to Stop screen I am referring to:

It will not override the n epochs setting if the consistency setting hasn't been met yet, both criteria have to be met before it will stop.

 

[Shawn Billings]

I think that's what Jim meant.

Consistency will keep you on point longer with fewer engines fixed and much shorter with more engines fixed. This inversely proportional relationship is helpful when moving from wide open points to obstructed points. In the open, a five to six engine fix is generally easily obtainable. In obstructed areas perhaps only two might be obtainable. Naturally you would want to observe longer in obstructed areas, consistency counter does this automatically. For example, to reach a consistency level of 10, with 2 fixed engines requires 100 epochs, while with 6 engines it only take 8. Consistency is a unitless arbitrary value that Javad came up with that's based on a logarithmic scale. You won't find it detailed in any reference material apart from J-Field documentation.

 

[Jim Frame]

Last week I was taking shots in the open with 6 engines fixed and the Consistency counter never went above zero. Is that normal behavior? Also, is there a way to invoke the Verify function when using the Stop Button setting?

 

[Shawn Billings]

Are you sure it wasn't the confidence counter, Jim. This is the first number, the second is consistency. If you don't have V6 resets on, then the confidence will not increment if you start with six engines and never subsequently lose and regain a fix.

With the Stop Button, the best way I'd know to do that would be to program one of the user buttons for Reset RTK which resets the engines. Before you press Stop, reset engines and wait for it to regain a fix and log a few epochs. It's the same thing.

 

[Matt Johnson]

Also, is there a way to invoke the Verify function when using the Stop Button setting?

It currently can be used like this in the Testing branch of J-Field, this may have just been recently changed and would explain why it doesn't work with the release version of J-Field.

 

[Shawn Billings]

Also, is there a way to invoke the Verify function when using the Stop Button setting?

Sorry, I misread this second part of your question.

 

[Jim Frame]

Are you sure it wasn't the confidence counter, Jim. This is the first number

Yes, sorry, it was the first number that never rose above zero.

 

[Jim Frame]

Also, I'd like to request that the Consistency counter display in fixed format. It's very distracting to see the display jump around as the number digits right of the decimal point switches around between none and 2 (which I think is the max).