Date: Wed, 10 Jun 1998 17:59:36 -0400 From: "Ellis, Dave - USAG-DPS" <ELLISD@forscom.army.mil> To: multimedia@FreeBSD.ORG Subject: Emergency Alert Signals Message-ID: <B184C118DFF3D011BB2700805FCCAF4901AD877F@exch2.forscom.army.mil>
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My name is Dave and a Fire Chief for the Fort McPherson Fire
Department, Directorate of Public Safety. I was doing some searching
about the emergency alert systems, their protocols, and different means
of transmitting. During my search I came across one of your messages
posted in the comp.dcom.telecom.tech.rec. newsgroup, on an article about
"Emergency Alerting System mystery". Someone from the list suggested
that I ask the list users for some help.
I have been doing a research and study on the EAS broadcasting
methods for a project I am working on. After I came across your
message, I was having hope that you could help answer a few questions.
I understand that the emergency alert signals that may come from
the national weather station are established protocols set by the FCC.
When the television stations receive this message, it is run through an
EAS decoder which transmits an English translation of the cryptic EAS
protocol to the character generator (CG) in ACSII. The EAS message is
then embedded and synchronized into the video of the playing program. I
guess this is what we see on our TV screens, a message crawling along
either the top or bottom of the screen.
My questions would be:
1. After a message (data) has been embedded and synchronized into the
video of the program, is there a way to separate, or grab, or translate
this data from the video after being transmitted to our television set
from the broadcast station?
Or let's say, I video taped a program and an emergency alert came across
the screen, can I grab this message from the video tape?
2. Do you have any suggestions, sources, etc. that can help accomplish
this?
3. Do cable systems have the same alerts, protocols, and format as that
of the air links?
I would highly appreciate any and all answers to my quest above. Since
I am not a subscriber to this list, please forward all correspondence to
the below e-mail address.
I thank-you for your time and consideration on this matter.
Dave Ellis
Directorate of Public Safety
1386 Troop Roll SW
Ft. McPherson, GA 30330-1069
ellisd@forscom.army.mil
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