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ServerTime: Broken
PageEdited: 19/10/2009
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| Kingscliff
(Meters)
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| Todays Sun, Moon & Tide |
Saturday
2010-09-04
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| Sun: rise5:57am-set5:33pm
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Moon: rise2:12am-set 12:50pm
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High: 4:28am
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0.8
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Low: 9:55am
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0.3
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High: 5:09pm
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1.4
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Low: 11:53pm
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0.3
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We sell and recommend ESET's Nod32 Antivirus.
BOM Precis Wednesday
Early fog patches. Sunny day. Light to moderate west to northwest winds tending
north to northeast near the coast in the afternoon and freshening.
Lismore: Sunny Max: 25°C
Cape Byron: Sunny Max: 23°C
Grafton: Sunny Max: 28°C
Sat, 4 Sep 2010 07:04
1-2ft SE swell The swell has
picked up overnight to
1-2ft, but it's pretty ugly
with moderate NE winds up
before the sun this morning.
Expected the NE'er to keep
pushing with around 25kts
due by this afternoon. If
you're desperate to get wet
(and who isn't!) try the
northern corners of the Spit
and Tweed back beaches.
Check the Coastalwatch
forecast. Wind: N/NE
15/20kts, increasing to
20/25kts during the
afternoon and reaching
25/30kts south of Cape
Moreton in the late
afternoon and evening. Sea:
1.7 metres, rising to 2.5
metres south of Cape
Moreton. Isolated showers.
19°C 66°F Wind:
11kts High Tide: 04:15 am &
04:54 pm Low Tide: 09:54 am
& 11:33 pm Air Temp: Max
24°C
© Copyright Coastalwatch.
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Phase: Waning Crescent
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Illumination: 19.2%
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Full in: 19 days
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| New in:
4 days
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4T Fingers Computing Tweed Bar - Wave & Swell Images
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Only 109 days to go until the Next Summer Solstice the longest day of the year.
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The Tweed River Bar - Wave Amplitude & Swell Size Images
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Images from "Water Research Laboratory", Uni. of NSW Site refThere was 1 week,
4 days,
22 hours,
0 minute and
0 sec of technical failures at the point Danger site Note: these images are the resuult of 'ARGUS' technology which was developed by the
'Coastal Imaging Lab (CIL) - Oregon State University'
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Tweed River Bar
Updated during Daylight Hours, when available! Debug Info. Source
"Kevins USO"
Rainbow Bay Updated during Daylight Hours, when available!
Source
Snapper Updated during Daylight Hours, when available!
Source
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The images are of the Tweed River Entrance And Rainbow located on the North Coast New South Wales (Australia).
The images are updated Hourly, on the half hour, (most of the time) during Daylight hours.
They are being collected and analysed to quantify beach conditions, following the construction of a sand
bypassing system at the nearby entrance to the Tweed River.
A Camera is mounted on the Captain Cook Memorial Lighthouse, hosted by the Point Danger Volunteer Marine Rescue Station.
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Waverider Bouy Tweed River Bar - Swell Size (Estimate) |
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Note: This is experimental.
Script has been updated on the 2/01/2009 1:51:12 PM. Source Update Hourly on the ½hr but is 2hrs behind real time. It is based on a script that reads the pixels of the Tweed River (wave height plot) below
HSIG: The average of the highest one third of the waves. The likely maximum wave height can be up to twice the significant wave height, occuring around 1 in 2000 waves. |
| Avg. Swell Sizes 2hrs Ago | 10hr Trend (avg:4.84m) | Avg. Swell Sizes 12hrs Ago |
| 4.84m with an Avg. Max of 4.84m | Stable | 4.84m with an Avg. Max of 4.84m |
Waverider Bouy Tweed River Bar - Wave Direction (Estimate) |
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Note: This is experimental and the accuracy is Weak at best.
Source Update Hourly on the ½hr but is 2hrs behind real time.
It is based on a script that reads the pixels of the Tweed River (wave direction plot) with 16-24 scans averaged to give the resultant direction
Click HERE to view the Graph
Key to Compass Points - 0° is NORTH, 90° is EAST, 180° is SOUTH and 270° is WEST |
| Wave Direction 2hrs Ago - SSW | 24hr Average - E | Wave Direction 24hrs Ago - NE |
| 206.0° | 95.4° | 36.4° |
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A Little Information About this Page
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There is a lot going on in the Background on The WEB Server When You Visit this page.
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For the TweedBar and Rainbow Images
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The Server First checks to see if the Present Hour is Within the Hours of Todays Sunrise
and Sunset or after Sunrise But before Midnight. The Process forks at this point.
1. Daylight Hours
The Server Next Checks to see if there is already images for the
Present Daylight Hour already locally cached.
If they do EXIST it will then send those Current Tweedbar and Rainbow images to your Browser.
If they are not cached the website Connection is checked and if it is available
the images are downloaded and processed and then sent to your Browser.
NB: Remember! The Present Hour is Available At 33mins Past the Hour.
2. Darkness Hours
If the present time is after Sunset But still before Midnight the server checks to see
if the Sunset Images exist.
If they do it will send those images to your Browser.
If the Sunset Images are not already cached the server downloads, processes and sends the Sunset images to your Browser.
3. Else
If The Present Hour is before Sunrise and no-one has visited the site between Sunrise and Midnight the
server delivers the Last previously processed Images of TweedBar and Rainbow. These images Might Be Yesterdays or even earlier,
Thems the Breaks! But Hey, it saves me Bandwidth on Useless Image Processing.
IE: It, (this server), always sends the cached
Images to your Browser BUT they might have to be downloaded & processed first. Which explains why a page refresh might Update the Images Displayed!
Downloading AND Processing
If there are No Currently Cached Images, It will proceed to Download the NEW image
from the University of New South Wales Coastal Imaging Department's website, (if it is available),
crop those images, backup the Previous Old Images to a new name that represents the Hour of the Page Display
(Which I will allow a Display of The Archives on another WebPage when I get time etc).
Explaination for the Speed Differences when this Page is Viewed.
If you are the First Visitor During That Hour Then You Will have to wait while the script runs, but
if you are the second, third, etc you will just get the images thus speeding up the display.
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For the TweedBar Swell Size and Direction
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Every Hour The Server downloads the
the Swell/Wave Height and Swell Direction Images. It then Crops the Downloaded Wave Height image and backs
up the last image. This is to enable faster Local Processing of the Graphical Data.
The TweedBar Swell Size
It, (this server), Reads the Images Pixels Using PHP's GD functions "imagecolorat()" &
"imagecolorsforindex()" and compares the resultant indexes of the amounts of red,blue,green used in the graph's plotlines
reading the appropriate x,y co-ordinates of a matched index, these are then scaled using the graph limits.
The Graph Limits are determined using The Same PHP's GD Functions to read plotlines pixels.
The Origin (x,y) is found using some very crude Optical Character Recognition PHP code to "see"
the Numeral used at the Origin point on the graph, IE: 0.1,2,3,4 etc
The Scale is then found by summing the PHP Code "seen" Y scale
tick marks along the Right Hand Edge of the Graph to "obtain" the number of meters the
scale covers, ie 13ticks = 3m, 17ticks = 4m etc
The results are the Delivered to Your Browser in a Table Showing the Current Images Reading, it's Previous Readings and the trend.
If the Size of the Swell is 1.5 meters or Greater the colour of the text is Pink. If it's size is below 1.5 meters the text is Grey
The TweedBar Wave Direction
This is performed using very similar code to The swell Size PHP script. The differences are in the Scale and the way the
Results are presented
The University Image Represents a Graph of Magnetic bearings on the Y Scale plotted against time on the X Scale...
- So that South is at BOTH the Top and the Bottom of the Y Scale.
- The ZERO point on the Y Scale is NORTH.
- The Top of the Graph shows Swell/Waves from The SE Quadrant and NE Quadrant.
- The Bottom shows Swell/Waves from The SW Quadrant and NW Quadrant. IE: WESTERLY WAVES
It can be Fairly Successfully assumed that a WEST Swell will be Fairly Unlikely! But Not impossible
As the WaveRider Bouy is Situated OffShore. The Chance of a Stong West wind on an otherwise Flat Sea will Produce Wind
Waves from the West, even if they are very small. Just like any other body of water.
So we don't need to find the origin of the Graph, it is constant, we just use 2 fixed Pixels to Degrees Ratio to register the Compass
Bearing the Swell/Waves are coming From. One Ratio for the EAST Top half of the graph and another for the WEST Bottom half.
Results are presented both as...
- A table showing the Current Bearing and The older 24 hours ago Bearing
- A PHP GD created Image Showing the Bearings.
Debugging Information: ( -Back- )
FileName: 2010090415.jpg
Cached Files are Already available! No Need to Download & Process
www.4tfingers.biz/tides/tweedbar.php
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