New Grib Presentation

[cagney]

I don't think that boat_alexandra needs any help with the code, as he found the bug. This is how it looks like with the bug fixed:



Zooming in further...



My source for OSCAR is query@svsarana.com!

Thomas

[rgleason]

Cagney... Thomas Thanks for clearing up my confusion.... that's right it did run in the grib_pi, I believe I posted an example of that, in fact Ptizef is posting the very same file I believe with the snakey read currents.... Thanks.

.hm ??? Standard O 3.2 displays OSCAR..., at least for me.
I'm not so lucky with the development versions....

Am very glad Sean and Jean figured out how to make the new_enhanced_gribs work with OSCAR currents.

Now I just have to figure out how to get the monthly kml grib data translated to grib so we can have 12 months of "Routing Gribs" -any suggestions for how to do that?

These montly files at Map » Pitufa.at , say "prev_winds_north_atlantic_01.kml" are Xml format with the main repetitive part being "Placemarks"

http://www.cruisersforum.com/forums/...rts-96792.html

See Post #9 and below

[seandepagnier]

actually I tried the kml stuff and it requires hundreds of images in addition to the files which are separate downloads. COGOW is basically pre-generated and in an image format which is not good to redistribute, and also not very good for something like weather routing (because it's images not data). I don't think you can easily convert it to gribs either.

I thought it would make more sense to use the SCOW data (in netcdf) format which is what I started on the climatology plugin.. but unfortunately this wind data only has 9 datapoints per lat/lon location per year, and while using frequency domain helps a lot, it seriously limits the actual data and does not capture systems that are only in place a few days or a week properly. Sure it would still get the trade winds, but would not capture when they are upset.

Both of these are based on quickscat measurements. So what I really need is the raw quickscat data, then I could generate gribs and a lot of other useful things.

In addition, it would be nice to take some grib files, and use this to extrapolate what likely wind would be for the next two weeks for starting passages based on previous trends as well. For this I need a lot of data, not averages.

Swell and wind/wave can be derived from wind if there is no better source and if it covers a large enough area.

So.. where do I get quickscat data? I can only find images for acending and decending passes. I guess this works and sample by pixels? How do I get wind direction?

[rgleason]

Thanks for looking at the montly files at Map » Pitufa.at, Sean and Post #9,

Wouldn't an index ....
If CDATA is [some file] Then = [Some angle] +
<name>8.47 kn scalar average</name>

Yield the Grib data at the Position information given in the Kml?

I will look for quicksat data. I like your thoughts/approach about climatology!

[yoruk]

Thank you Jean Pierre
This is great. an example here this morning
absolutely perfect, and more ... no rain
just a little wind
Michel

[rgleason]

This New_Grib grib_pi.doc above has some of the same issues with reading certain grib current files as the one in grib_enhancements thread, see that thread please. I just checked it. Jean Paul, I had sent you an invitation to my Opencpn dropbox folder which had many different types of grib files and grib current files. If you need it sent again, let me know.

I believe the problem has to do with reading a slightly different format for the various "frames" with date and time.

[yoruk]

Hello
We can always do more complicated. But like this, zyGrib and Sailsdoc is sufficient for many people ...
Michel

[cagney]

Originally Posted by boat_alexandra

actually I tried the kml stuff and it requires hundreds of images in addition to the files which are separate downloads. COGOW is basically pre-generated and in an image format which is not good to redistribute, and also not very good for something like weather routing (because it's images not data). I don't think you can easily convert it to gribs either.

I thought it would make more sense to use the SCOW data (in netcdf) format which is what I started on the climatology plugin.. but unfortunately this wind data only has 9 datapoints per lat/lon location per year, and while using frequency domain helps a lot, it seriously limits the actual data and does not capture systems that are only in place a few days or a week properly. Sure it would still get the trade winds, but would not capture when they are upset.

Both of these are based on quickscat measurements. So what I really need is the raw quickscat data, then I could generate gribs and a lot of other useful things.

In addition, it would be nice to take some grib files, and use this to extrapolate what likely wind would be for the next two weeks for starting passages based on previous trends as well. For this I need a lot of data, not averages.

Swell and wind/wave can be derived from wind if there is no better source and if it covers a large enough area.

So.. where do I get quickscat data? I can only find images for acending and decending passes. I guess this works and sample by pixels? How do I get wind direction?

There is much more to COGOW than the images.
Check these two links for a different, text presentation.
http://cioss.coas.oregonstate.edu/co....75N_1.75E.dat
http://cioss.coas.oregonstate.edu/co....25N_5.75E.txt

You get to these pages through a dialog that pops up on left clicking the graphics.


Thomas

[Gilletarom]

To all developers grib plugin.

Would it be possible to have a pot file with all new items all the beta versions of GRIB plugin? This would allow translators to work.

Best regards

Gilletarom.

[rgleason]

Dear Jean Pierre

I was snooping around in here
https://github.com/Ptizef/OpenCPN/tr...lugins/grib_pi

trying to figure out why I could not git your new grib plugin.
I noticed that you had made some changes 6 days ago.

Can you advise regarding the correct git path?
Also, I need to use sean's branch sean/grib_enhancements to build it now...correct?

Thanks.

[rgleason]

Sean on Climatology

I thought it would make more sense to use the SCOW data (in netcdf) format which is what I started on the climatology plugin.. but unfortunately this wind data only has 9 datapoints per lat/lon location per year, and while using frequency domain helps a lot, it seriously limits the actual data and does not capture systems that are only in place a few days or a week properly. Sure it would still get the trade winds, but would not capture when they are upset.

Both of these are based on quickscat measurements. So what I really need is the raw quickscat data, then I could generate gribs and a lot of other useful things.

In addition, it would be nice to take some grib files, and use this to extrapolate what likely wind would be for the next two weeks for starting passages based on previous trends as well. For this I need a lot of data, not averages.

Swell and wind/wave can be derived from wind if there is no better source and if it covers a large enough area.

So.. where do I get quickscat data? I can only find images for acending and decending passes. I guess this works and sample by pixels? How do I get wind direction?

Just found on this website:

QuikSCAT/SeaWinds Data products
"QuikSCAT nominal mission ended on November 23, 2009. "

More on Jeff Peters blog:

Dr. Jeff Masters' WunderBlog : QuikSCAT, 1999 - 2009: R.I.P. | Weather Underground
"Launched in 1999, the QuikSCAT satellite became one of the most useful and controversial meteorological satellites ever to orbit the Earth. Forecasters world-wide came to rely on QuikSCAT wind data to issue timely warnings and make accurate forecasts of tropical and extratropical storms, wave heights, sea ice, aviation weather, iceberg movement, coral bleaching events, and El Niño. Originally expected to last just 2-3 years,"

Alternatives to QuikSCAT
Two valuable alternatives to QuikSCAT are available, but neither can come close to making up for the loss of QuikSCAT. The Windsat instrument aboard the Coriolis satellite (launched in 2003) measures wind speed and wind direction using a different technique. Evaluation of these data at NHC and NOAA's Ocean Prediction Center (OPC) shown the winds to be unreliable in and around the storm environment. There's also the European ASCAT satellite, launched in 2007. Like QuikSCAT, ASCAT can measure global wind speed and direction twice per day. However, the data is available at 25 km resolution (two times coarser than the 12.5 km QuikSCAT), and ASCAT covers only 60% of the area covered by QuikSCAT


A QuikSCAT replacement
A replacement dual-frequency QuikSCAT satellite that has superior capabilities to old one is being explored by NOAA and NASA, in partnership with the Japanese Space Agency (JAXA). The new QuikSCAT instrument would fly on the Japanese GCOM-Water Cycle satellite, scheduled to launch in January 2016. However, funding must begin in 2010 in order to meet this launch deadline, and no funding for a new QuikSCAT has been put into the Administration's FY 2011 budget. The proposed QuikSCAT replacement would be able to measure winds as high as 100 mph (Category 2 hurricane strength), and have improved ability to measure winds in heavy rain.

[rgleason]

January 29, 2013
PASADENA, Calif. - In a clever reuse of hardware originally built to test parts of NASA's QuikScat satellite, the agency will launch the ISS-RapidScat instrument to the International Space Station in 2014 to measure ocean surface wind speed and direction.

The ISS-RapidScat instrument will help improve weather forecasts, including hurricane monitoring, and understanding of how ocean-atmosphere interactions influence Earth's climate.

ISS Rapid Scat to take the place of QuickScat
WINDS: ISS-RapidScat

Applications WINDS: About Scatterometry: Applications
http://coaps.fsu.edu/scatterometry/m...OWSTPoster.pdf

OSCAT (India) Description of OSCAT Data Products
QucikScat using NOAA& JPL Seawinds on Space Station
Description of QuikSCAT Data Products
QuikSCAT/SeaWinds Data products

[rgleason]

RSS / WindSat Data / Browse

[rgleason]

Quickscat
Scatterometry Data - World Winds from QuickSCAT

Here is one data access to Quickscat I think
ERDDAP - Wind Stress, QuikSCAT, Global, Science Quality (3 Day Composite) - Data Access Form

Also shows the data structure.

[Ptizef]

Originally Posted by rgleason

Dear Jean Pierre

I was snooping around in here
https://github.com/Ptizef/OpenCPN/tr...lugins/grib_pi

trying to figure out why I could not git your new grib plugin.
I noticed that you had made some changes 6 days ago.

Can you advise regarding the correct git path?
Also, I need to use sean's branch sean/grib_enhancements to build it now...correct?

Thanks.

Hi Rick

I don't see why you couldn't git NEW_GRIB . This address works perfectly
I repeat it but it will change nothing
https://github.com/Ptizef/OpenCPN/tree/NEW_GRIB
What appends when you open it ?
let me know ...
Jean Pierre