Expedition Navigation Software / YB tracking downloads

**Posted by nav** 2/27/2021 5:05 am

Hello,
1) Is there a way to get Expedition to check which position report steps are already downloaded and to then download only new position report steps / steps that are not downloaded already?

This could bring data traffic down by avoiding downloading the same positions multiple times.

2) Would it be possible to show the file size of the position report download before hitting the download button?

3) "JSON since" does not seem to work for me at the moment. It just downloads a very small file.
I'd expect, that for a past race (for example "c6002020"), when I enter the starting date and time of this race, Expedition would then download the whole race: everything since the start. But this is not the case.

**Posted by Ernie M** 2/27/2021 5:43 am

Nav,
1/3. The file that is out at say https://yb.tl/c6002020-expedition.txt is only the latest snapshot of the fleet.
In a 'Tracker' like Exp it gets saved with an extension of the date/time. So when you have tracked a race from start to finish you can go back in time, in the tracker. But if you start downloading after the race has finished the data is fixed. Otherwise the file would be as you say huge. YB already has lots of files out there on their server as you can see at https://yb.tl/links/C6002020 for every event. Multiplying that by each sample time would be pretty big.
2. a Nick question

Ernie

**Posted by Nick** 2/27/2021 12:13 pm

As Ernie says.

If size is an issue, most people just download the single positions. The format is much more compact too.

The JSON Since option has never worked for me. I have mentioned it to YB and leave it in Exp in case it gets fixed one day.

**Posted by Ian W** 11/14/2021 6:47 pm

A few questions about YBT display in Expedition which I am sure have simple answers about which tab/box etc to select

1. During a race or after a race how do I "replay" the history time steps to see how the fleet moved down their tracks.
2. When doing this replay can I just view the track to the time step like YBT/club website trackers do .... hiding the track yet to be sailed in future time steps
3. How to I get the boat names to appear on the YBT tracks
4. Can we display boat icons at the last YBT position again like YBT/club websites

This is in the category ... I think I used to be able to do this but can't remember how. !

**Posted by Nick** 11/14/2021 7:42 pm

The positions are interpolated to the display time (the weather etc display time).

There isn't a way to step through the position time steps, but you can step through time steps in your grib data or select the display time and move through using the weather controls.

The boat name should be automatically shown.

There is a sync time option on the Sail ribbon. This sets the display time to the last position for the reference boat.

**Posted by Ian W** 11/14/2021 10:24 pm

Thanks Nick ... helping he work through how to improved boat tracking

Re Q1 ... I did what you suggested and can step through with weather controls but limited to 60minute step and nothing shorter?. I can also enter display time manually for say 10 or 20 minute steps but quite slow.
Q3 and Q4 now working.
Q2 ... you did not answer ... is there a way?

New Questions
5. Tool tip held over other boats gives time, coords, GPS COG and SOG and Expedition Calculated Trk COG and SOG ..... can it be made to display range to reference boat like it is provided if we open race tracking dialogue box using AIS?
6. Is there an easy way to display change from YBT in bearing and range in time plot style to monitor changes?
7. Related .... is there a way to do this via AIS tracking for boats in AIS range

**Posted by Ian W** 11/14/2021 10:27 pm

Oops ... Q 5 should just have read

5. Tool tip held over other boats gives time, coords, GPS COG and SOG and Expedition Calculated Trk COG and SOG ..... can it be made to display range to reference boat like it is provided if we open race tracking dialogue box ?

AIS got inserted in wrong spot .. just Q7

**Posted by Nick** 11/14/2021 11:27 pm

Q2 - there isn't.

You can tell Exp how many minutes to step at a time or use the grib time steps.

The race tracking is completely separate from AIS. You can map AIS to Expedition boats if you want to track them.

**Posted by Ian W** 11/14/2021 11:45 pm

Nick

I should maybe not introduced an AIS tracking question at end of my YBT but to clarify

Q2

Q5 .... my question is about YBT data display (range) that Expedition calculates and displays in race tracking dialogue box but not showing in tool tip pop up .... nothing to do with AIS tracking

Q6 .... no answer ..... YBT info question ...... Is there an easy way to display change from YBT in bearing and range from us as reference boat and others in time plot style to monitor changes? ? The data is available for each time step in your race tracking dialogue box

Q7 .... the only AIS tracking question .... Is there an easy way to display change from AIS in bearing and range from our boat to others in time plot style to monitor changes?

**Posted by Campbell_Field** 11/15/2021 2:33 am

Ian W wrote:
Q7 .... the only AIS tracking question .... Is there an easy way to display change from AIS in bearing and range from our boat to others in time plot style to monitor changes?

Yes, in Stripchart.