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Links to the latest
SeaSonde software below:
Intel and PPC
Radial Software:
SSRadialSuiteCD_10R5
http://www.seasonde.com/
Combine Software:
SSCombineCD_10R5
Request
download via email:
Advisories: - There is an indexing bug in
the radial processing tools that may cause radials in different
range cells to be placed on offset azimuthal spokes if the
radial resolution in the Header.txt does not match the radial
resolution of your measured antenna pattern file. For
instance, if you set the radial processing to use 5 degree
resolution, but your antenna pattern resolution is 1 degree,
you may see radials in range cell 3 fall on the 15, 20, 25,
etc. spokes, but in range cell 4 they may fall on 16, 21,
26, etc. spokes. Radial directions will be off at most
by 1/2 of your radial resolution. This does not affect
processing with ideal antenna patterns. A fix will
be available soon.
- A bug has been found in the Wave Model tools released in late 2005. Calculated "Wave
Direction" measurements are incorrect. The tool has been corrected in Intel/PPC
Release5 only. Cross Spectra can be re-processed with the new tools to obtain
the correct measurements.
Note: CODAR Ocean Sensors,
Ltd. no longer supports Mac OS 9 software.
SeaSonde OS X software upgrades are free
for all SeaSonde owners.
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Site
Maintenance:
Tips for Effective
Data Management
- By Hector Aguilar
CODAR Ocean Sensors
A frequently overlooked issue with SeaSonde sites is the use of hard drive space
in the SeaSonde site computer. OS X, unlike previous Apple operating systems,
no longer freezes up completely when the disk fills up but will protect itself
from grievous harm due to lack of processing space. To prevent unnecessary loss
of data, it is highly recommended to budget your drive space. The following is
recommended:
1) Use a large external drive
for archival purposes.
a) Using an external drive allows for a duplicate of the data on the SeaSonde
main drive to be made immediately, thus protecting the data from any chance of
computer failure.
b) A longer history of archived data can be maintained on site.
c) An external archive drive setup allows for a quick swap out with a fresh external
drive that immediately increases storage space without having a long download
time to deal with.
2) Archivalist can help you budget your hard drive space efficiently
and easily.
With Archivalist you can:
a) Archive data from real-time output folders to the external drive and computer
hard drive simultaneously.
b) Set limits on the number of archive folders kept on the computer hard drive
so that older folders are deleted
before the maximum capacity of the hard disk is reached.
c) Decide which types of data files to archive and how long to keep them.
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Here is a table that lists the average size of common files found on a SeaSonde.
Note: these are for a 5 MHz system. Whether they are archived in weekly or monthly
folders in the Archives depends on the individual Archivalist settings.
| Type |
Single File size |
File Unit |
Average
Drive Space Used |
| CSS files (CSS) |
2.5 MB |
30 minutes |
2.1GB per month |
| Wave (WVLM) |
1.5 MB |
monthly |
200KB-1MB per month |
| Radial files (LLUV) |
4 to 240 KB |
hourly |
11-30 MB per week (x2) |
| Diagnostic files (STAT) |
~ 300 KB |
weekly |
x2 1.3- .4 MB per month |
3) The occasional 'spring cleaning' of the hard disk is also
a good habit to develop in maintaining a well performing computer. Decide on
an external drive swap trip to the remote site every three to six months depending
on the rate at which data is being stored on the site. Two or more external drives
can be employed for sites that are more difficult or cost prohibitive to visit
or if you just prefer to have redundancy.
4) Running the Disk Utility (in the /Applications/Utilities/
folder) at regular intervals is also recommended. With Disk Utility you can verify
the disk integrity, de-fragment the hard disk and verify system permissions.
Although hard drive failures are not common, they do occur and Disk Utility can
help as an early warning or prevention tool to reduce downtime.By taking the
time to perform these steps the operator can be assured of a healthy computer
and good management on
the radial data being generated by SeaSonde.
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Property
Lists:
Understanding SeaSonde
Suite Settings
- By Hector Aguilar
As many SeaSonde users may have noticed, CODAR has recently shifted away from
using plain text files to using property lists, an xml file format, for its preference
files. Within these files, users will find the information used to control the
operation of most of the Radial and Combine Tools Suite programs. There are some
good reasons to do this:
1) Use of key/values
pairs
Property lists are arranged by property
keys and corresponding values. These values can
be boolean (yes or no) or alpha numeric values.
This makes property lists easy to use, the values
are easily modifiable and can be kept track of
with little ambiguity.
2) No order required
in the property file
Our original ASCII text preference files had to be placed in a specific order.
This is no longer the case. Properties can be in any order as long as each key
remains with its corresponding value. This has allowed for centralization of
property lists. The latest SeaSonde Suites put most of the lists in the RadialConfig
or CombineConfig folders for ease of modification. While some properties are
still using text lists, further updates will eventually make all preferences
into property lists.
3) Developer tools available
SeaSonde developers can use built-in tools available on any computer running
OS X. Links for PERL developers wanting to utilize property lists are listed
at the end of the article. You can also use the 'defaults' command to modify
individual property values in a property list without editing the file directly.
This prevents corruption of the data format. More information on this command
can be obtained by executing a 'man defaults' command in a terminal bash shell
window.
4) Finally, property lists can
be modified on the fly. This allows for SeaSonde
applications to implement any new settings on
the next data iteration without having to restart
the application.
Here is an example of the SeaSonde Acquisition plist seen when opened with a
text tool:
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Unless one is familiar with XML code, reading a property list can be difficult
to understand and time consuming to read using a text editor. In order to make
things easier, we recommend the third party program, Pref Setter. Pref Setter
reads
the plist XML code and displays them in an easy to read and edit format:
We strongly recommend that you read the format guides in the “Documents” folder
installed on SeaSonde Radial and Central site computers and request that you
discuss alternative settings with CODAR Support personnel before making changes
to these lists.
Links for those interested in managing property lists using PERL:
Part 1:
http://www.macdevcenter.com/pub/a/mac/2005/07/29/plist.html
Part 2:
http://www.macdevcenter.com/pub/a/mac/2005/08/02/plist.html
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| Tech's
Corner |
It’s
About Time
- By Bruce Nyden
CODAR Ocean Sensors
This article addresses several important issues relating to time zone selection,
computer clock adjustments and re-processing of data collected with differing
time zones. It was inspired in part by recent questions involving the construction
of larger networks using SeaSondes with differing time zones.
Advancements in HF radar technology over the last few decades have provided the
means to measure ocean surface currents on very large spatial and temporal scales
in near real-time. What initially started as a few isolated SeaSonde sites has
rapidly expanded in recent years. Networks have merged together to create a “big
picture” view of coastal currents on near-continental scales. Nowhere is
this more evident then national network being developed for the continental U.S.
(see http://cordc.ucsd.edu/projects/mapping/maps/).
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A Common Language for Time and Space
In order to construct a real-time surface current map at continental scales all
of the contributing HF radar sites must share common temporal and spatial datums.
The spatial datum used by SeaSonde software for all output data is the WGS 84
spheroid. From the spatial aspect all SeaSonde users already have a common datum
for standardized mapping of current vectors. The temporal datum used for SeaSonde
processing is user selectable. The choice of time zone (i.e. temporal datum)
has created a few obstacles when agencies and academic institutions have attempted
to
merge their networks. A common time zone must first be agreed upon.
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Merging SeaSonde networks
facilitated the need for standardized temporal
and
spatial datums
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Time
Zones and Time Offsets
You’ve probably noted that new computers shipped from CODAR are configured
with Reykjavik, Iceland as the time reference. Why Iceland and not Greenwich,
England? There are three good reasons for this 1) Iceland is in the UTC (i.e.
0 hrs offset, 2) Iceland does not observe “Summer Time” (the English
equivalent of Daylight Savings Time) and 3) the Reykjavik zone is selectable
in the Date/Time control panel map. The problem with “Summer Time” and “Daylight
Savings Time” adjustments is that time is lost in Spring as clocks are
set forward and time is duplicated in the Fall when clocks are set back. Any
time zone that changes its offset with respect to UTC is not a good choice to
begin with.
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Reykjavik, Iceland is in
the GMT zone and has no Daylight Savings
Time
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The
time zone (temporal datum) of choice
for large HF radar networks is UTC, Coordinated
Universal Time. UTC is also the default
used by GPS receivers and this makes
it very easy to incorporate ancillary
data into custom real-time displays.
UTC and GMT (Greenwich Mean Time) are
often used interchangeably. There are
subtle technical differences but for
our purposes we consider them the same.
For more information please contact:
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Tech Note:
If you are using OS X 10.3 or higher there is a way to have data produced
in the local time zone without the effects of daylight savings by manually
setting the zone using the Mac’s built-in list and the Unix Terminal
window (not all zones are shown on the map interface):
To set computer to a time zone from the list (for example GMT+8 for PST)
use the following command:
/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/systemsetup
-settimezone Etc/GMT+8
This will keep the computer in PST without changing to savings time.
To see all of the time zones installed in your Mac’s database send
the following command in the Terminal window:
/System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/systemsetup
-listtimezones
Mac OS X uses the 'Zoneinfo' a.k.a. 'tz' database” which is updated
every year.
Apple has just released a software update that includes recent changes
in the dates that Daylight Savings Time is observed in the US. the most
up-to-date time zone database, but advanced users can download and compile
a new time zone database independent of the OS updates.
For more information on this database and time zone management in general
see: http://www.twinsun.com/tz/tz-link.htm
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Who tells the Mac what time it is?
Macs get their initial time and time zone
settings from you, the user. Once connected
to the Internet they can be configured
to automatically check and reset the clock
if necessary using a network timeserver.
Timeserver clock adjustments are made with
respect to the time zone and location that
you have selected in the Date/Time pane
of your System Preferences. One cautionary
note, if the network timeserver you chose
is unreliable, incorrect or has a flakey
connection this can create more problems
then just having an inaccurate computer
clock. If the clock hiccups while trying
to snynchronize itself to a time server
it is possible that data acquisition will
be interrupted or erroneous data will be
produced.
GPS SHARES? equipped SeaSondes have their
own built-in time servers. The GPS software
will sync the Mac’s clock automatically
whether or not the computer is connected
to the Internet. Precision timing is crucial
for SeaSondes sharing the same frequency.
The SHARES? software periodically issues
a command to check the AWG Controller for
the current time. The AWGController is
regimented by the incoming GPS time signals. |
Lost Date and
Time
If a Mac computer is disconnected from
the power grid for too long or its memory
back-up battery dies it will eventually
lose its date, time and critical desktop
settings. A few earlier Mac models would
become so dead that even the “Restart
After Power Failure” preference would
fail to work when the power was finally
restored. This required a site visit (to
push the “power on” button)
to re-start processing. One solution for
sites with long and frequent power outages
is to implement an intelligent UPS backup
system (see our Summer newsletter). The
intelligent UPS utilizes scripting and
USB communications to shutdown a laptop
Mac when a power loss is detected and the
UPS has reached some pre-defined voltage.
The same scripting periodically starts
up the computer to conduct voltage checks
on the power grid and UPS battery reserve.
If the power has been restored, SeaSonde
processing will resume.
If a Mac does power up after a power outage
it still may have lost its date and time.
When this happens, the date changes to
the Mac’s default reference date
which is less than the year 2000. SeaSonde
software implements a “Lost the Date” script
every time it starts up. If a date year
earlier than 2000 is detected it will stop
data acquisition until this is rectified.
If it is a GPS SHARES? equipped SeaSonde
system it will find the correct time again
after the oscillator oven in the GPS module
has warmed up and satellites have been
re-acquired. |
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Data
Re-Processing:
Adjusting the Time Offset
in Radial file
Suppose you decide to abandon your favorite local time zone to a join
larger network consortium operating on a different time zone then yours
and you want to convert your old archival data set to match the new format
for consistency.
CODAR has just the tool for this job! It is called RadialAdjuster and
is located in the folder /Codar/Seasonde/Apps/Tools/ in SeaSonde10 Releases
3, 4 and 5. To use it, simply launch the program, Pull down the File-> Preferences
menu (shown below). Once you make the changes and save your preferences
you can convert large batches of files by dragging and dropping a folder
onto the RadialAdjuster icon. The converted files are output in the same
directory as the originals.
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Radial Adjuster Preferences
If your
archival data contain vintage OS 9 Rads
and Radz radials you can use the tool called CtfRadialer (also found in the “Tools” folder)
to convert large batches of Rads/Radz radials to the newer Rdli/Rdlm (LLUV) format.
The converted OS 9 files will contain all of the column headings of an LLUV file
but some of these columns will be empty. The calculation of quality information
was implemented in the OS X radial processing tools. To recover this information
from OS 9 data, you need to re-process the CSS files with OS X software. The
converted OS 9 radials can be used for combining even with the empty meta-data
columns.
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Pairing Radials
by Time
SeaSonde10 Combine software requires that
all Macs in the network be set to the same
time zone. Files are combined based on
the date, time and zone (offset from UTC)
in the file header metadata and not the
name stamp of the file. The offset is applied
to the internal time and date stamp before
the match up for combining. It is possible
to have radials from two sites that are
paired in time by the file name stamp but
don’t combine when the Combine processing
runs. To rule out the possibility that
the two sites were set on different time
zones, view the files with a text editor
and see if the time zones and time offsets
match (see sample file metadata in the
boxed note below): |
Tech
Note:
SeaSonde radial and total vector files
are ASCII files and can be read with
any text editor. The time reference
can be viewed in the first few lines
of the file header.
Sample “Classic” Radial
File Date/Time Stamp (Line 1):
10:00 AM Saturday, August 16, 2003
PST -1151094496
Sample “LLUV” Radial File
Date/Time Stamp (Lines 1 -7):
%CTF: 1.00
%FileType: LLUV rdls "RadialMap"
%LLUVSpec: 1.03 2006 10 05
%Manufacturer: CODAR Ocean Sensors.
SeaSonde
%Site: SEA1 ""
%TimeStamp: 2003 08 16 10 00 00
%TimeZone: "PST" -7.000 1
Sample Name Date/Time Stamp
RDLi_NAME_2006_12_27_0200.ruv
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At the present
time there are no time zone metadata built
into time series, range, CSQ, CSS or CSA
files. Time adjustments have to be made
at the radial level.
Be advised that OS 9 radials don’t
have an offset reference to UTC (note Line
1 in the Rads example above). File matching
and file conversion with OS 9 is based
on the assumption that the three letter
time zone codes are specific to one and
only one zone. Recently we’ve found
that there are duplicate zone codes that
can cause confusion. CST for example can
be Central Standard Time or China Standard
Time. The time offsets from UTC for these
two are clearly different.
In future releases of our Combining software
we plan to implement an option that will
allow all data to be acquired with reference
to UTC for large scale networks but have
an option to output total vectors in whatever
time zone is desired for local scale displays.
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In
summary:
If you’re just setting up your SeaSonde for the first time, your best bet
is to use the UTC time zone for your processing.
Use a network timeserver to automatically set/correct your computer clock only
if your SeaSonde is not equipped with GPS SHARES? and the timeserver has a reliable
connection
If you are unsure about what time or zone a radial or total represents, use a
text editor to read the header metadata. |
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CODAR
Quiz
Rules of the game:
- You must be able to provide a valid SeaSonde serial number (if asked) or be
on our newsletter mailing list in order to play the game.
- Only one entry per person is allowed
- CODAR employees are not eligible
- One winner will be drawn from all of the correct responses submitted before
March 31, 2007 at midnight.
Send your answer to  (failure
to use this email address will result in disqualification).
The Winter Issue prize will be ....
- A beautiful black zippered portfolio with the "CODAR" logo, seen
at the right.
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Here’s
the question:
On the day of Superbowl XLI (2007) at exactly midnight GMT this mysterious interference
was observed in the spectra of a 42MHz SeaSonde located at 373834N 1222812W.
The interference lasted just under an hour and has never been observed since.
Question: What caused this?
A spectra from the event is shown below:
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A spectra illustrating the SeaSonde's "normal mode" is shown below
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| If you have any questions,
please email us: |
CODAR
Quiz Winner (from our Fall 2006 Newsletter)
John Perez of Texas A & M was the winner
of our Fall Newsletter Quiz. His name was
drawn from a hat containing the names of
the seven entrants with the correct answer.
The question was:
In what country is the city of Codar located?
The answer we were looking for
was:
India. The City of Codar is located in
the State of Arunachal Pradesh, India at
15.4N latitude and 74.05E longitude
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Announcing
CODAR’s Spring 2007 SeaSonde Training
Course
Our Spring Training Course will be
held in Mountain View, California at our
Corporate Offices located at 1914 Plymouth
Street.
The four-day course will begin
Tuesday 1 May at 9:30AM and end Friday
4 May at 3:00PM
There will be a "Happy Hour" gathering
on Monday April 30 at 6 PM at The Tied
House Restaurant in Mountain View.
Software sessions will focus on our new
Intel/PowerPC SeaSonde 10 Release 5 software
suite and the field sessions will be conducted
at SeaSonde sites in the San Francisco
Bay area.
Course Tuition:
Tuition is USD $750 per person, and includes
course materials, 4 lunches, two dinners.
New SeaSonde owners should contact for priority reservations.
For more information on the Spring Training
Course, CLICK HERE
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Crissy Feild SeaSonde installation |
| If
you have any questions, please email us: |
1914 Plymouth Street
Mountain View, CA 94043 USA
Phone: +1 (408) 773-8240
Fax: +1 (408) 773-0514
www.codar.com |
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