Navigational Warning Msgs from NGA.mil

[requiem]

I would be very happy to see something similar for the local notices to mariners. My practice with those is to do similar to what I believe svonadym has in mind, e.g. adding a note to the chart whenever applicable. Attached are two examples, one a point, the other a point and range. (Where it to include a number of coordinates I'd use them to mark out a polygon.)


There is a daily LNM update described and linked to from here: https://www.navcen.uscg.gov/?pageNam...ailyDiscrepXML

It only includes data from sections II and III unfortunately; I also update my charts to reflect the entries in sections I and VII.

[Antipole]

Originally Posted by svonadym

Perhaps the amount of work exceeds the usability, but plotting these points with a mention of the warning number, type (e.g., "hazardous operations") and cancel date would be ideal.

Is it easier to access and open the compressed message, then translate the formatted text, or to parse the plain text after being pasted to a TXT file or UI? Is this endeavor too much hassle for the benefit?

Suggest you post here a text file containing several examples (6?) so we can see the pattern of them. No promises but we could have a look.

[SeanPatrick]

FWIW, I was able to get the points into OpenCPN in a matter of a minute or two without much fuss. I used the link provided by Nohal in post #3, but I could just as easily have used the text below.

Originally Posted by svonadym

32-36N 118-20W, 32-12N 119-18W,
32-22N 119-28W, 32-32N 119-18W,
33-02N 118-38W.

The process I use goes something like this:

1. Copy and paste the coordinates into Excel.
2. Convert from DMS to decimal degrees (one can use formulas to make this step "automatic").
3. Ensure the columns have "headers" (labels at the top of the column indicating what they are, i.e.: Name, Lat., Lon.)
4. Save as CSV.
5. Use GPSBabel to convert to GPX waypoints.
6. Import into OpenCPN.
7. Connect the dots. (Haven't figured out how to make GPSBabel do this in a way that makes sense yet.)

See attached screenshots (click to enlarge). Maybe not the most elegant solution, but it works and - as I said - is relatively painless. Beats entering them all manually, anyway.

Cheers!

[requiem]

My instinct with this is to use the Draw plugin to annotate the zones. It appears to accept CSV (at least with some tweaking), which means you can omit the GPSBabel step.

ref: https://opencpn-manuals.github.io/ma...0.1/index.html

Example using your coordinates:

'c','type(B)','name','boundary_type','visible(t/f)','line rgb-colour','rgb-fill-colour'
'B','Obscure Warning','Exclusion','t','rgb(0,255,0)','rgb(255,0,0)'
'c','type(BP)','name',lat,lon,'boundary_type','visible','rings-visible(t/f)','rings-number','rings-step','rings-units(N/K)','rings-colour'
'BP','first',32.6,-118.3333333
'BP','second',32.2,-119.3
'BP','third',32.36666667,-119.4666667
'BP','fourth',32.53333333,-119.3
'BP','fifth',33.03333333,-118.6333333
'/B'

[svonadym]

Originally Posted by Antipole

Suggest you post here a text file containing several examples (6?) so we can see the pattern of them. No promises but we could have a look.

I much appreciate any additional thoughts on the matter.

Here's a PDF with 11 examples received over the past month or two. Text file uploads are limited to 1KB and my original was 5KB, therefore the PDF. Hopefully it's not too much of an inconvenience.

[Antipole]

Having examined the sample messages you posted, I conclude that the free form makes it too hard to automate completely.

So I have created a script for the JavaScript plugin that presents a form into which you can paste the relevant information.

As as an example

050613Z FEB 22
NAVAREA XII 68/22(18).
EASTERN NORTH PACIFIC.
CALIFORNIA.
1. HAZARDOUS OPERATIONS 101430Z TO 110130Z AND
111430Z TO 112100Z FEB IN AREA BOUND BY
32-36N 118-20W, 32-12N 119-18W,
32-22N 119-28W, 32-32N 119-18W,
33-02N 118-38W.
2. CANCEL THIS MSG 112200Z FEB 22.

You would enter this in the form thus:



On selecting enter the script checks that the position coordinates and expiry data (if any) are in the correct format. It then creates an object in OpenCPN.

If only one position is provided, it creates a waypoint and incorporates the description and expiry date in the description field.

If more than one position is provided, it creates a closed route with the positions as routepoints. The plugin is unable to access a route's description field, so it stashes the description in the From attribute and the expiry in the To field.

In both cases, the name is prefixed with the tag NGA:

Expiries

When the script starts up, it first checks for previously created tagged objects and examines their expiry date.

If they have expired, it presents the option to delete them.

Using the utility
I have put this script in the shared scripts library. To use it, download the script and store it somewhere. Then load it into the scripts pane of the JavaScript plugin and run it.

The script assumes the positions and expiry date are as formatted in NGA notices. If you want to use it with other formats, it would need tweaking.

Enjoy

[svonadym]

Thank you for all your effort, Antipole. The script seems to work very nicely for me. There are a couple tweaks I was hoping to make, but I don't know enough to do it:


1. Any attempt to paste multiple lines of text into the Description field fails. It only pastes the first line.


2. For waypoints, I'd like to display the Name by default. (I presume this is managed through OCPNaddSingleWaypoint().

Can I make a simple change to the script for these?
Thanks again

[Antipole]

Originally Posted by svonadym

1. Any attempt to paste multiple lines of text into the Description field fails. It only pastes the first line.

2. For waypoints, I'd like to display the Name by default. (I presume this is managed through OCPNaddSingleWaypoint().

1. Fixed - I had mis-capitalised multiLine in the field specification.

2. A sensible choice. You need to add isNameVisible:true to the waypoint attributes, as described in the user guide.

I have made both changes to the NGA.js script. It is updated in the library. Re-download it from here.

[svonadym]

Terrific! Thank you.

[BobMc]

I cannot seem to get the NGA info in any format other than dd-mm-ssN dd-mm-ssW here on the east coast. Is there any easy way to convert to the dd-mmN dd-mmW format? or would it be possible to modify the j-script to accommodate the dd-mm-ssN dd-mm-ssW format?

Here's an example of what I get using two different options at the NGA site:
28-35-55N 080-35-07W, 28-36-00N 080-32-00W,
28-35-00N 080-24-00W, 28-22-00N 080-00-00W,
28-19-00N 080-02-00W, 28-30-33N 080-33-04W, 28-32-11N 080-33-45W

Thanks for any suggestions!

[Antipole]

Originally Posted by BobMc

I cannot seem to get the NGA info in any format other than dd-mm-ssN dd-mm-ssW here on the east coast. Is there any easy way to convert to the dd-mmN dd-mmW format? or would it be possible to modify the j-script to accommodate the dd-mm-ssN dd-mm-ssW format?

Dead easy actually. This is all handled in the formDegs sub-function, which splits the string at the '-'. JavaScript really is a delight for this sort of thing.

I have updated the script in the library to handle both with or without seconds. You need re-download it, of course.

[BobMc]

It work perfectly, now, with the change you made. Thank you for your help!