CalCOFI Drifter Realtime Webpage Info - Revision history

Kirk at 06:50, 10 July 2009

2009-07-10T06:50:12Z

Kirk at 06:48, 10 July 2009

2009-07-10T06:48:50Z

Kirk at 06:47, 10 July 2009

2009-07-10T06:47:11Z

Kirk at 06:46, 10 July 2009

2009-07-10T06:46:56Z

Kirk ireson at 21:03, 26 June 2009

2009-06-26T21:03:53Z

Kirk ireson at 20:44, 26 June 2009

2009-06-26T20:44:29Z

Kirk ireson at 19:08, 26 June 2009

2009-06-26T19:08:48Z

Kirk ireson: New page:

CalCOFI SVP Drifter Realtime Webpage Wiki

NOTES AND THINGS TO KNOW ABOUT THE SVP REALTIME PAGE
Jun, 2009 Kirk Webpage: [http://www.icess.ucsb.edu/drifter/realtime-SVP/ SVP R...

2009-06-25T20:08:17Z

New page: <h1>CalCOFI SVP Drifter Realtime Webpage Wiki</h1> NOTES AND THINGS TO KNOW ABOUT THE SVP REALTIME PAGE<br> Jun, 2009 Kirk Webpage: [http://www.icess.ucsb.edu/drifter/realtime-SVP/ SVP R...

New page

<h1>CalCOFI SVP Drifter Realtime Webpage Wiki</h1>

NOTES AND THINGS TO KNOW ABOUT THE SVP REALTIME PAGE<br>
Jun, 2009 Kirk

Webpage:
[http://www.icess.ucsb.edu/drifter/realtime-SVP/ SVP Realtime Page]

There are three main parts needed to display the data (details below):<br>
1. Fetching the data (using Python script running on dub-locl)<br>
2. Parsing the data (using PHP script running on website)<br>
3. Displaying the data (using Javascript running on your browser)<br>

<h2>1. FETCHING THE DATA</h2>

On dub-locl.icess.ucsb.edu in /localhome/kirk/scripts/ there is a script 'expect_script_to_fetch_argos_data.py'. It uses 'pexpect', a Python version of the 'expect' scripts, which allows you to script what would normally be an interactive terminal session. This is necessary in this case because we have to obtain the data via a telnet session.
<ul>
<li>There is essentially nothing to configure it, and it's well documented should you need to change anything. It is set to fetch the last 24hours worth of positions.

<li>It may need to be updated with drifter numbers as more are sent drifting.

<li>It is set to run every 6 hours via a "cron job" in the kirk account. To edit this job, as kirk, at the Terminal, type 'crontab -e' and use 'vi' style editing commands, or 'crontab -l' to just show it. (To become kirk, login as drift, then in a Terminal, type 'sudo su -' (then type the drift password) to become root, then 'su kirk' to become kirk.)

<li>It saves the output of this session to /home/locl/file_sharing/SVP_CALCOFI_LATEST_DATA.txt on the ICESS network (which is accessed on dub-locl via /mnt/locl/, which should be mounted automatically if the system reboots, see /etc/fstab)
</ul>

<h2>2. PARSING THE DATA</h2>

When someone visits the webpage (http://www.icess.ucsb.edu/drifter/realtime-SVP/), in the ajax.js file there is instruction to fetch the data. This 'fetch' is accomplished by calling 'parse_argos_data.php' in that directory. This php script reads the file saved above (in /home/locl/), ignores all the non-data lines, and processes/cleans up the crazy ARGOS format output from the telnet session.

It outputs 1 record per position report in this format:
drift_no,YY-MM-DD,HH:MM:SS,milliseconds_since_Jan01_1970,orig_report_num,lat,lon,position_type(1=GPS,0=ARGOS),SST(C),batt(V)
e.g.
<pre>
75428,2007-04-03,10:33:37,1175610817000,137,+26.6979,-081.9557,1,NaN,12.4 (a gps position)
</pre>
<ul>
<li>There is very little configuring it, and it's well documented should you need to change anything.

<li>Its output can be seen easily:
http://www.icess.ucsb.edu/drifter/realtime-SVP/parse_argos_data.php
</ul>

<h2>3. DISPLAYING THE DATA (at [http://www.icess.ucsb.edu/drifter/realtime-SVP/ realtime page]) </h2>

The Google mapping code was adapted from the Iridium/Microstar realtime page at http://www.icess.ucsb.edu/drifter/realtime/

The two main javascript files are ajax.js and map.js.

The javascript files are compressed using http://www.icess.ucsb.edu/drifter/realtime/JavascriptCompressor.html, so changes made to the xxx__UNCOMPRESSED__.js files won't show up on the page unless they are compressed and saved without the "__UNCOMPRESSED__" portion in the name, OR at the beginning of index.php those two types of files are commented/uncommented out as appropriate.

<h2> POTENTIAL PROBLEMS / TROUBLESHOOTING</h2>

Prob: The data file (/home/locl/file_sharing/SVP_CALCOFI_LATEST_DATA.txt) is not getting saved/updated
<ul>
<li>Is the dub-locl computer up?
<li>Is /mnt/locl mounted on dub-locl? It should come up automatically
<li>Has 6 hours passed since the last time it ran? It only runs every 6 hours
<li>Try fetching the data yourself via telnet (do these commands at a terminal prompt):
</ul>
<pre>
telnet datadist.argosinc.com
hansen (at the 'Username:' prompt)
aomlus (at the 'Password:' prompt)
prv,7325,ds,,93561-93587 (at the '/' prompt, to get the previous 9 day's worth of data for drifter #93561-93587 )
lo (at the '/' prompt, to log out)
</pre>

NOTE: if you want to get data from a specific time period, use julian dates and GMT hours after the comma after 'ds'.
For example:
<pre>
prv,7325,ds,174/12-175/10,93561-93587 (for June 23rd at 12Z through June 24th at 10Z)
</pre>

Prob: The data file (/home/locl/file_sharing/SVP_CALCOFI_LATEST_DATA.txt) shows no data
<ul>
<li>There probably aren't any drifters talking in the last 24hours (look for the line "No data available or authorization failure" in the file or try manually getting the data)
</ul>

@@ Line 71: / Line 71: @@
 ddMMMyy.LOG-GZ, for example: 15JUL09.LOG-GZ   (i.e. for july 15th, 2009)<br>
 <br>
 ----

@@ Line 31: / Line 31: @@
 This PHP script on dub-local.icess.ucsb.edu (called by the fetching script above) is /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/parse_calcofi_argos_svp_data.php and is pretty well documented. It breaks down the fairly cryptic GPS encoding and then saves it to a friendly format. It archives this file to /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/DATA_ARCHIVE/yyyymmdd_CALCOFI_SVP_LATEST_DATA.txt and copies this file to /home/kirk/public_html/drifter/realtime-SVP/CALCOFI_SVP_LATEST_DATA.txt so the website has access to it.<br>
 <br>
+<ul>
 It outputs 1 record per position report in this format:<br>
 <pre>
@@ Line 41: / Line 43: @@
 ,2007-04-03,10:33:37,1175610817000,137,+26.6979,-081.9557,1,NaN,12.4,2007-04-03_11:33:30,2   (a gps position)
 </pre>
 <br>
 <h2>3. DISPLAYING THE DATA   (at [http://www.icess.ucsb.edu/drifter/realtime-SVP/ realtime page] or [http://svp.drifterdata.com http://svp.drifterdata.com]) </h2>

@@ Line 26: / Line 26: @@
 <li>It fetches their file, archives it (to /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/DATA_ARCHIVE/), uncompresses it, and starts the parsing script (see next section).
 </ul>
+<br>
 <h2>2. PARSING THE DATA</h2>

@@ Line 180: / Line 180: @@
 <br>
 <b>NOTES:</b><br>
--Total bit count of all 7 lines must equal the checksum value or
+-Total bit count (a very non trivial calculation) of all 7 lines must equal the checksum value or
 message block is considered garbled and thus ignored.<br>
 <br>

← Older revision		Revision as of 19:08, 26 June 2009
Line 81:		Line 81:
	<li>There probably aren't any drifters talking in the last 24hours (look for the line "No data available or authorization failure" in the file or try manually getting the data)		<li>There probably aren't any drifters talking in the last 24hours (look for the line "No data available or authorization failure" in the file or try manually getting the data)
	</ul>		</ul>
		+
		+	----
		+	<h2>INFO ABOUT TIME CALCULATION</h2>
		+	Basically each data block is for three hourly reports, and data blocks can be repeated (I
		+	have no idea how that's determined), and there is a slight adjustment
		+	to the time based on "fix delay" (or "Length of Acquisition", which is
		+	usually on the order of <60 seconds).<br>
		+	<br>
		+	For example (showing the second to last block in the existing file as
		+	I write this):<br>
		+	<pre>
		+	07325 93575 15 27 N 3 2009-06-25 20:18:59 34.416 240.156 0.000 401652653
		+	2009-06-25 20:21:22 3 12 62 678 94
		+	00 01 344156 01
		+	1198452 01 04 689
		+	01 344155 01 1198448
		+	01 04 661 01
		+	344156 01 1198448 01
		+	04 587 00
		+	</pre>
		+	<br>
		+	This first line contains ARGOS only info:
		+	<pre>
		+	prog_num 07325
		+	drift_num 93575
		+	lines_in_sat_pass 15
		+	num_sensors 27
		+	sat_name N
		+	resolution 3
		+	time 2009-06-25 20:18:59
		+	xmit_lat 34.416
		+	xmit_lon 240.156
		+	xmit_alt 0.000
		+	xmit_freq 401652653
		+	</pre>
		+	<br>
		+	The next 7 lines contain 3, hourly GPS reports.<br>
		+	<br>
		+	---- Line 1: (2009-06-25 20:21:22 3 12 62 678 94)<br>
		+	<pre>
		+	BASE Date/Time 2009-06-25 20:21:22
		+	# identical messages rcvd 3
		+	Drogue count over last half hour 12
		+	Battery voltage = n * 0.2 62 -> 12.4V
		+	SST(C) = x * 0.043 - 5 678 -> 24.154
		+	Checksum 94
		+	</pre>
		+	<br>
		+	---- Line 2: (00 01 344156 01)<br>
		+	<pre>
		+	Msg ID 00 -> this is 1st message sent
		+	Valid Pos #1 (1=good, 0=bad) 01 -> good
		+	Lat #1 (ten-thousandths of degree) 344156 -> 34.4156
		+	Lat #1 Ref (0 = South, 1 = North) 01 -> North
		+	</pre>
		+	<br>
		+	---- Line 3: (1198452 01 04 689)<br>
		+	<pre>
		+	Lon #1 (ten-thousandths of degree) 1198452 -> 119.8452
		+	Lon #1 Ref (0 = East, 1 = West) 01 -> West
		+	Pos #1 Length of Acq (seconds = n * 4) 04 -> 16(seconds)
		+	SST #1 (C) = x * 0.043 - 5 689 -> 24.627
		+	</pre>
		+	<br>
		+	---- Line 4: (01 344155 01 1198448)<br>
		+	<pre>
		+	Valid Pos #2 (1=good, 0=bad) 01 -> good
		+	Lat #2 (ten-thousandths of degree) 344155 -> 34.4155
		+	Lat #2 Ref (0 = South, 1 = North) 01 -> North
		+	Lon #2 (ten-thousandths of degree) 1198448 -> 119.8448
		+	</pre>
		+	<br>
		+	---- Line 5: (01 04 661 01)<br>
		+	<pre>
		+	Lon #2 Ref (0 = East, 1 = West) 01 -> West
		+	Pos #2 Length of Acq (seconds = n * 4) 04 -> 16(seconds)
		+	SST #2 (C) = x * 0.043 - 5 661 -> 23.423
		+	Valid Pos #3 (1=good, 0=bad) 01 -> good
		+	</pre>
		+	<br>
		+	---- Line 6: (344156 01 1198448 01)<br>
		+	<pre>
		+	Lat #3 (ten-thousandths of degree) 344156 -> 34.4156
		+	Lat #3 Ref (0 = South, 1 = North) 01 -> North
		+	Lon #3 (ten-thousandths of degree) 1198448 -> 119.8448
		+	Lon #3 Ref (0 = East, 1 = West) 01 -> West
		+	</pre>
		+	<br>
		+	---- Line 7: (04 587 00)<br>
		+	<pre>
		+	Pos #3 Length of Acq (seconds = n * 4) 04 -> 16(seconds)
		+	SST #3 (C) = x * 0.043 - 5 587 -> 20.241
		+	Null bits (only for padding, ignore)
		+	</pre>
		+	<br>
		+	<br>
		+	<b>NOTES:</b><br>
		+	-Total bit count of all 7 lines must equal the checksum value or
		+	message block is considered garbled and thus ignored.<br>
		+	<br>
		+	-Times of GPS reports are calculated thusly:<br>
		+	<br>
		+	1) Take BASE time, subtract (Msg ID*3) [that is, if message has been
		+	repeated, it is at least 3 hours old -- I have a switch in my code
		+	(it's turned on for now) which will ignore messages with a message
		+	ID>0 because the original may be also present, and it's possible the
		+	duplicate isn't an exact duplicate and then you get slightly different
		+	reports at similar times]<br>
		+	2) Then, subtract 2 hours for Pos #3, and 1 hour for Pos #2 and 0 for Pos #1<br>
		+	3) Then subtract the associated small "Length of Acq"<br>
		+	<br>
		+	Thus, the 2nd GPS time (i.e. #2) would be calculated thusly:<br>
		+	<pre>
		+	BASE time: 2009-06-25 20:21:22
		+	minus 0 hours (because Msg ID is 0)
		+	minus 1 hour (because it's Pos #2)
		+	minus (pos #2 length of acq) 16 seconds
		+
		+	equals: 2009-06-25 19:21:06
		+	</pre>
		+	<br>
		+	An additional wacky thing is that due to repetition of the messages,
		+	or god knows what, the calculations of the reports you see aren't
		+	necessarily in chronological order. So, after doing all the
		+	calculations, I then sort them chronologically before outputting
		+	(within the parse_argos_data.php script), so that when showing the
		+	track lines, the points are in order.<br>

@@ Line 10: / Line 10: @@
 There are three main parts needed to display the data (details below):<br>
 . Fetching the data (using Python script running on dub-locl)<br>
-. Parsing the data (using PHP script running on website)<br>
+. Parsing the data (using PHP script running on dub-locl)<br>
 . Displaying the data (using Javascript running on your browser)<br>
@@ Line 16: / Line 16: @@
 <h2>1. FETCHING THE DATA</h2>
-On dub-locl.icess.ucsb.edu in /localhome/kirk/scripts/ there is a script 'expect_script_to_fetch_argos_data.py'.  It uses 'pexpect', a Python version of the 'expect' scripts, which allows you to script what would normally be an interactive terminal session.  This is necessary in this case because we have to obtain the data via a telnet session.
+On dub-locl.icess.ucsb.edu in /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/ there is a Python script 'fetch_calcofi_svp_data.py'.
 <ul>
-<li>There is essentially nothing to configure it, and it's well documented should you need to change anything.  It is set to fetch the last 24hours worth of positions.
+<li>There is essentially nothing to configure it, and it's well documented should you need to change anything.  It is set to fetch via ftp from ftp.aoml.noaa.gov for the last 9 days worth of positions.
-<li>It may need to be updated with drifter numbers as more are sent drifting.
+<li>It may need to be updated with drifter numbers and temperature coefficients as more are sent drifting.
-<li>It is set to run every 6 hours via a "cron job" in the kirk account.  To edit this job, as kirk, at the Terminal, type 'crontab -e' and use 'vi' style editing commands, or 'crontab -l' to just show it.  (To become kirk, login as drift, then in a Terminal, type 'sudo su -' (then type the drift password) to become root, then 'su kirk' to become kirk.)
+<li>It is set to run about every 6 hours (05:30, 11:30, 17:30 & 20:30 Pacific, and they should post the data at 8am Eastern Time) via a "cron job" on the kirk account.  To edit this job, as kirk, at the Terminal, type 'crontab -e' and use 'vi' style editing commands, or 'crontab -l' to just show it.  (To become kirk, login as drift, then in a Terminal, type 'sudo su -' (then type the drift password) to become root, then 'su kirk' to become kirk.)
-<li>It saves the output of this session to /home/locl/file_sharing/SVP_CALCOFI_LATEST_DATA.txt on the ICESS network (which is accessed on dub-locl via /mnt/locl/, which should be mounted automatically if the system reboots, see /etc/fstab)
+<li>It fetches their file, archives it (to /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/DATA_ARCHIVE/), uncompresses it, and starts the parsing script (see next section).
 </ul>
 <h2>2. PARSING THE DATA</h2>
-When someone visits the webpage (http://www.icess.ucsb.edu/drifter/realtime-SVP/), in the ajax.js file there is instruction to fetch the data. This 'fetch' is accomplished by calling 'parse_argos_data.php' in that directory.  This php script reads the file saved above (in /home/locl/), ignores all the non-data lines, and processes/cleans up the crazy ARGOS format output from the telnet session.
+This PHP script on dub-local.icess.ucsb.edu (called by the fetching script above) is /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/parse_calcofi_argos_svp_data.php and is pretty well documented. It breaks down the fairly cryptic GPS encoding and then saves it to a friendly format. It archives this file to /localhome/kirk/Scripts/CalCOFI_ARGOS_SVP_scripts_and_data/DATA_ARCHIVE/yyyymmdd_CALCOFI_SVP_LATEST_DATA.txt and copies this file to /home/kirk/public_html/drifter/realtime-SVP/CALCOFI_SVP_LATEST_DATA.txt so the website has access to it.<br>
 It outputs 1 record per position report in this format:<br>
@@ Line 37: / Line 38: @@
 e.g.
 <pre>
-,2007-04-03,10:33:37,1175610817000,137,+26.6979,-081.9557,1,NaN,12.4,2007-04-03_11:33:30,2    (a gps position)
+,2007-04-03,10:34:45,1175610885000,136,+26.6980,-081.9550,0,NaN,NaN,NaN,NaN    (an argos position)
 </pre>
 <ul>
 <li>There is very little configuring it, and it's well documented should you need to change anything.
 </ul>
-<h2>3. DISPLAYING THE DATA   (at [http://www.icess.ucsb.edu/drifter/realtime-SVP/ realtime page]) </h2>
+The Google mapping code was adapted from the Iridium/Microstar realtime page at [http://www.icess.ucsb.edu/drifter/realtime/ http://www.icess.ucsb.edu/drifter/realtime/]
 <h2> POTENTIAL PROBLEMS / TROUBLESHOOTING</h2>
-Prob: The data file (/home/locl/file_sharing/SVP_CALCOFI_LATEST_DATA.txt) is not getting saved/updated
+Prob: The data file (/home/kirk/public_html/drifter/realtime-SVP/CALCOFI_SVP_LATEST_DATA.txt) is not getting saved/updated
 <ul>
 <li>Is the dub-locl computer up?
-<li>Is /mnt/locl mounted on dub-locl? It should come up automatically
+<li>Is /home/kirk/ mounted on dub-locl? (It should come up automatically)
-<li>Has 6 hours passed since the last time it ran? It only runs every 6 hours
+<li>Has 6 hours passed since the last time it ran? It only runs about every 6 hours (see above), but they only update the file once per day at 8am Eastern.
-<li>Try fetching the data yourself via telnet (do these commands at a terminal prompt):
+<li>Try fetching the data yourself via ftp:
 </ul>
 <pre>
-telnet datadist.argosinc.com
+ftp://ftp.aoml.noaa.gov/phod/pub/daily_buoydata/7325/
-hansen     (at the 'Username:' prompt)
+login: anonymous
-aomlus     (at the 'Password:' prompt)
+pass: e_mail
 </pre>
+Look for a file of today's data with the following name format:
 NOTE: if you want to get data from a specific time period, use julian dates and GMT hours after the comma after 'ds'.
 For example: