This is tomorrow...

http://www.navcen.uscg.gov/pdf/AIS/LNM_Special_Notice_for_NAIS_Testing_21OCT2014.pdf

USCG NATIONWIDE AUTOMATIC IDENTIFICATION SYSTEM (NAIS) NETWORK TESTING
On October 21, 2014, the U.S. Coast Guard (USCG) will conduct AIS test messaging from all
USCG NAIS base stations located across the United States; for up to 15 minutes on the hour,
from 1100-2215 UTC. These messages can be identified by their Maritime Mobile Service
Identity (MMSI) number: 003669139 or 00366613 and by the words ‘USCG TEST’ within their
contents. This is the first of many tests the USCG will conduct in the future as it seeks to provide
another timely delivery source of navigational information and services to promote safety,
efficiency, and integration of the Marine Transportation System (MTS). 

Messages to be tested: AIS Application Specific (ASM) messages 8, 25, and 26, with DAC = 001,
367, FI’s = 0, 22, 29, 33, or 35; AIS Safety Related Text (SRM) messages 14, of various lengths,
using repetitions of the text ‘USCG TEST’. For further information on AIS messages, DACs, and
FI’s visit http://www.navcen.uscg.gov/?pageName=AISMessages. 

Mariners capable of decoding these messages can ignore them and should contact the USCG
Navigation Center at 1-703-313-5900 or TIS-PF-NISWS@uscg.mil should they encounter any
negative impacts due to the testing.

Encrypting non-military/law enforcement AIS is a bad idea

It was recently brought to my attention that some high level people are proposing that the IMO require a class of civilian (aka not military or law enforcement) vessels to use encrypted AIS to broadcast their position.  This is an absolutely terrible idea.

Having ships broadcast their location encrypted defeats the primary safety aspect of AIS for those vessels, the encrypted messages do not expose their slot usage and thereby drastically increase the number of packet collisions in a local area (decreasing safety for normal AIS traffic), and encryption key management is not work well of large population of mariners.  It would be a disaster in safety, technical and political terms.

The traditional "blue force" AIS units are just class A devices with slightly modified software (I own one).  There really shouldn't be any cost difference.  You could also change the programming for class B devices and have them transmit the encrypted position messages, but please don't do that.

debian/fink and mbsystem

schwehr.org is currently in a "transitional stage"... it will be back soon.  Too much going on with the group of use all hosting together for us to get this settled right away.

Jonny B asked a question this morning about tides and mbsystem.  I didn't know the answer, but here is how I went about investigating.  This is on a mac with 10.7 and fink.  Hopefully this will give people some ideas about how to dig through what is around.  "dpkg -L" lists the files in a package.  As Jonny B said with a reference to the movie The Matrix, "Yowza, nice kung fu!".  I didn't have a fish to give, so the best I could do was point to the tackle store and say you might be able to get what you need to fish in there.


# Which fink packages deal with sonar?
fink apropos sonar
# If you already know about mbsystem...
fink list mbsystem
fink install mbsystem
dpkg -L mbsystem | grep tide
# Nothing
cd ~/Desktop
ls /sw/src/mbsystem*
# See that the latest tar is version 5.3.1917
tar xf /sw/src/mbsystem-5.3.1917.tar.gz
cd mbsystem-5.3.1917
find . | grep -i tide
# Nothing


find . | xargs grep -l tide | wc -l
# 84
find . | xargs grep -l tide
# ./html/mbdatalist.html
# ./html/mbio.html
# ./html/mbnavadjust.html
# ./html/mbotps.html
# ./html/mbprocess.html
# ./html/mbset.html
# ./html/mbsystem.html
# ./html/mbsystem_how_to_get.html
# ./install_makefiles
# ./man/man1/mbdatalist.1
# ./man/man1/mbnavadjust.1
# ./man/man1/mbotps.1
# ./man/man1/mbprocess.1
# ./man/man1/mbset.1
# ./man/man1/mbsystem.1
# ...
# ./src/utilities/mb7kpreprocess.c
# ./src/utilities/mbcopy.c
# ./src/utilities/mbinfo.c
# ./src/utilities/mbprocess.c
# ./src/utilities/mbset.c


man mbset
# "Apply tides to bathymetry."

schwehr.org

Yes, http://schwehr.org is currently offline.  InReach's colo facility is in a bad state.  When I get a chance, I will find another place to get schwehr.org and my blog hosted.

4/24/2012 9:00am PST We continue to evaluate the existing HVAC system and initial indications for a repair are at least several weeks and possibly longer. We understand this is not an ideal situation so we would suggest to all of our customers that start moving as soon as possible to alternative locations in order to ensure servers and services remain up.

Although we want to avoid it a full analysis may include a disruption of power. No definitive time, date or duration for this power disruption is scheduled but it could be within the next few days. We will update you all with the specifics once they become known.

We are addressing security concerns as well and we have engaged the building management to help but their solution is to keep the door closed to the suite which will increase heat.

Using Google Cloud Storage - Part 1

This is my first attempt at a tutorial for Google Cloud Storage.

Using Google Cloud Storage… it's a service that let's you read/write data objects (a blob of data of what ever type you want).  Right now, you get 5GB of storage for free and you can transfer 20 GB per month. Beyond that, you'll have to check the pricing.

This is pretty much what is on https://developers.google.com/storage/docs/getting-started and https://developers.google.com/storage/docs/hellogooglestorage I've tweaked it a bit to fit my style. I'm doing this on a mac with fink and splitting between two acounts. I want to end up with a way to transfer files from one group to another. I started off by watching this 2011 Google IO video:

Google I/O 2011: Storing Your Application's Data in the Google Cloud

First setting up a virtual env in python to isolate us from messing up any existing python installs.

cd ~/Desktop
mkdir try-gs
cd try-gs
fink install virtualenv-py27
virtualenv ve
source ve/bin/activate
wget http://commondatastorage.googleapis.com/pub/gsutil.tar.gz
tar xf gsutil.tar.gz
pushd gsutil

# gsutil does not have a proper setup.py that will work with virtualenv
# so force it to play along
perl -pi -e "s|/usr|`pwd`/../ve|g" setup.py

python setup.py install
popd

You should now have a working virtualenv with gsutil installed in it. Your normal python will not be effective. You will have to rerun the <b>activate</b> from any other shell that you want to have access to gsutil. The virtualenv named "ve" will change your prompt:

$ pwd
/Users/schwehr/Desktop/try-gs
(ve)
$ 

Let's test out setup.

type python
# python is hashed (/Users/schwehr/Desktop/try-gs/ve/bin/python)
type gsutil
# gsutil is /Users/schwehr/Desktop/try-gs/ve/bin/gsutil
gsutil --help 
# lots of help scrolls by

# Try a world readable test data set
gsutil ls gs://uspto-pair/applications/0800401*
# gs://uspto-pair/applications/08004010.zip
# gs://uspto-pair/applications/08004011.zip
# gs://uspto-pair/applications/08004012.zip
# gs://uspto-pair/applications/08004013.zip
# gs://uspto-pair/applications/08004016.zip
# gs://uspto-pair/applications/08004017.zip
# gs://uspto-pair/applications/08004019.zip
gsutil ls -l gs://uspto-pair/applications/08004010.zip 
#       3410  2010-09-29T20:14:15  gs://uspto-pair/applications/08004010.zip
# TOTAL: 1 objects, 3410 bytes (3.33 KB)
gsutil cp gs://uspto-pair/applications/08004010.zip .
md5sum 08004010.zip 
# 04b4877377c16b1b49f19b0c7e161d04  08004010.zip

I have yet to write up using the oauth2 authentication.  Hopefully, I'll get that done soon.

See Also:

• http://code.google.com/p/gsutil/
• Issue 92 covers using pypi / pip / distribute / setuptools

RT 26 - Part 6: Parsing binary SBET files with python's struct

html, mp3, pdf and 26-python-binary-files-part-5.org

RT 25 - R for Statistics

Rob Braswell was our guest lecturer covering R for statistical analysis.

mp3, pdf of screenshots, 25-R-lab1-Intro.pdf, 25-r-statistics.org (on bitbucket via hg).