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GPS SOS routing and delay

 

This isn't strictly JMT-related, but hopefully acceptable anyway.
?
I was reading an article about a Death Valley employee who went for a hike,
had some route confusion, ran out of water and had to SOS on his Garmin.
Excerpt below.? My question is, what is the routing of an SOS to explain
why it was 1:40 between pushing the button and the cognizant NPS et al
receiving the message???
?
I read another article about the hiking group that found the remains of
Julian Sands on Mt. Baldy.? They hit the SOS button and had a response?
in 8 mins. (which I thought was pretty amazing).
?
The DV excerpt:
?
"By 4:30 p.m., his water bottle was empty, and “heat and dehydration caught up with
him,” officials said in the news release. That’s when he fainted and fell.
“After an unknown period of time, he woke up bruised and realized it was time to
call for a rescue,” the news release read, noting he used the SOS function on his
Garmin tracking device at around 6 p.m. to get help.
NPS rangers and the Inyo County Sheriff’s Office received the call at 7:40 p.m."
 

Hello Peter,
?
GPS provides the information to determine your location; the satellite communication network is Iridium.
?
The SOS message goes from your inReach to the next Iridium satellite; these are low earth orbit (LEO) ones so that the local constellation changes quickly, within minutes; do not assume it is just over your head, it can have a quite low elevation where there may be obstacles. From there either directly to a ground station or, if you are on a quite remote location like on the sea far away from land, via other Iridium satelltes to the ground station. - From there to the GEOS center, who inform then local authorities about the incident.
?
The GEOS center may need some time to access the situation, by calling your emergency phone # to find out if you are really out somewhere and the SOS is legit and not a malfunction, and ask back via inReach to you for details of the emergency.
?
Delay in the technical communication may happen if your location has a good part of the sky blocked. My experience stems from normal messaging, not SOS. My?mini 1 has a pretty bad GPS receiver so that it happens quite often that it cannot determine its?location, while my?phone can; the mini 2 is said to have much better GPS reception. No location information means?no SOS (other messages can be sent without location information if you choose). It may also happen that the path to the Iridium satellite is blocked; think about a deep valley, dense tree coverage, ... - on a typical hike in the Sierra sending tracking information every ten minutes it may typically happen more than once a day that a tracking point cannot be sent because of such reason.
?
Under favourable conditions a message goes out within seconds; but it may also need an hour sometimes, in the evening in the tent between trees in a valley.
?
Henning
?
Gesendet:?Freitag, 23. August 2024 um 05:41 Uhr
Von:?"Peter Klein via groups.io" <pklein95014@...>
An:[email protected]
Betreff:?[JMT-groups.io] GPS SOS routing and delay
This isn't strictly JMT-related, but hopefully acceptable anyway.
?
I was reading an article about a Death Valley employee who went for a hike,
had some route confusion, ran out of water and had to SOS on his Garmin.
Excerpt below.? My question is, what is the routing of an SOS to explain
why it was 1:40 between pushing the button and the cognizant NPS et al
receiving the message???
?
I read another article about the hiking group that found the remains of
Julian Sands on Mt. Baldy.? They hit the SOS button and had a response?
in 8 mins. (which I thought was pretty amazing).
?
The DV excerpt:
?
"By 4:30 p.m., his water bottle was empty, and “heat and dehydration caught up with
him,” officials said in the news release. That’s when he fainted and fell.
“After an unknown period of time, he woke up bruised and realized it was time to
call for a rescue,” the news release read, noting he used the SOS function on his
Garmin tracking device at around 6 p.m. to get help.
NPS rangers and the Inyo County Sheriff’s Office received the call at 7:40 p.m."

--

 

Henning:

I should have known that.? I used to rent a sat phone when going on solo
trips to the hinterlands (before the days of GPS units).? It used IIRC the
Globalstar sat network and connections were spotty at best.? I can't tell
you how many times I was balanced on a tall boulder or tramping off?
to a canyon rim to try to get a sat connection.? Globalstar was forever
promising to launch new sats to improve performance.? Iridium was
a definite improvement, and I assumed that the sat connection would
be quick and reliable by now.? Thanks.

Pete

On Fri, Aug 23, 2024 at 3:56?AM Henning Rech via <whrech=[email protected]> wrote:
Hello Peter,
?
GPS provides the information to determine your location; the satellite communication network is Iridium.
?
The SOS message goes from your inReach to the next Iridium satellite; these are low earth orbit (LEO) ones so that the local constellation changes quickly, within minutes; do not assume it is just over your head, it can have a quite low elevation where there may be obstacles. From there either directly to a ground station or, if you are on a quite remote location like on the sea far away from land, via other Iridium satelltes to the ground station. - From there to the GEOS center, who inform then local authorities about the incident.
?
The GEOS center may need some time to access the situation, by calling your emergency phone # to find out if you are really out somewhere and the SOS is legit and not a malfunction, and ask back via inReach to you for details of the emergency.
?
Delay in the technical communication may happen if your location has a good part of the sky blocked. My experience stems from normal messaging, not SOS. My?mini 1 has a pretty bad GPS receiver so that it happens quite often that it cannot determine its?location, while my?phone can; the mini 2 is said to have much better GPS reception. No location information means?no SOS (other messages can be sent without location information if you choose). It may also happen that the path to the Iridium satellite is blocked; think about a deep valley, dense tree coverage, ... - on a typical hike in the Sierra sending tracking information every ten minutes it may typically happen more than once a day that a tracking point cannot be sent because of such reason.
?
Under favourable conditions a message goes out within seconds; but it may also need an hour sometimes, in the evening in the tent between trees in a valley.
?
Henning
?
Gesendet:?Freitag, 23. August 2024 um 05:41 Uhr
Von:?"Peter Klein via " <pklein95014=[email protected]>
An:?[email protected]
Betreff:?[JMT-groups.io] GPS SOS routing and delay
This isn't strictly JMT-related, but hopefully acceptable anyway.
?
I was reading an article about a Death Valley employee who went for a hike,
had some route confusion, ran out of water and had to SOS on his Garmin.
Excerpt below.? My question is, what is the routing of an SOS to explain
why it was 1:40 between pushing the button and the cognizant NPS et al
receiving the message???
?
I read another article about the hiking group that found the remains of
Julian Sands on Mt. Baldy.? They hit the SOS button and had a response?
in 8 mins. (which I thought was pretty amazing).
?
The DV excerpt:
?
"By 4:30 p.m., his water bottle was empty, and “heat and dehydration caught up with
him,” officials said in the news release. That’s when he fainted and fell.
“After an unknown period of time, he woke up bruised and realized it was time to
call for a rescue,” the news release read, noting he used the SOS function on his
Garmin tracking device at around 6 p.m. to get help.
NPS rangers and the Inyo County Sheriff’s Office received the call at 7:40 p.m."

--

 

Rescue can take even longer, sometimes days, depending on location and weather. So while Garmin and other sat devices are a boon, they are not a substitute for proper gear, self reliance, and survival equipment.?

"When you see a new trail, or a footprint you do not know, follow it to the point of knowing."? - Uncheedah


On Fri, Aug 23, 2024 at 8:52?AM Peter Klein via <pklein95014=[email protected]> wrote:
Henning:

I should have known that.? I used to rent a sat phone when going on solo
trips to the hinterlands (before the days of GPS units).? It used IIRC the
Globalstar sat network and connections were spotty at best.? I can't tell
you how many times I was balanced on a tall boulder or tramping off?
to a canyon rim to try to get a sat connection.? Globalstar was forever
promising to launch new sats to improve performance.? Iridium was
a definite improvement, and I assumed that the sat connection would
be quick and reliable by now.? Thanks.

Pete

On Fri, Aug 23, 2024 at 3:56?AM Henning Rech via <whrech=[email protected]> wrote:
Hello Peter,
?
GPS provides the information to determine your location; the satellite communication network is Iridium.
?
The SOS message goes from your inReach to the next Iridium satellite; these are low earth orbit (LEO) ones so that the local constellation changes quickly, within minutes; do not assume it is just over your head, it can have a quite low elevation where there may be obstacles. From there either directly to a ground station or, if you are on a quite remote location like on the sea far away from land, via other Iridium satelltes to the ground station. - From there to the GEOS center, who inform then local authorities about the incident.
?
The GEOS center may need some time to access the situation, by calling your emergency phone # to find out if you are really out somewhere and the SOS is legit and not a malfunction, and ask back via inReach to you for details of the emergency.
?
Delay in the technical communication may happen if your location has a good part of the sky blocked. My experience stems from normal messaging, not SOS. My?mini 1 has a pretty bad GPS receiver so that it happens quite often that it cannot determine its?location, while my?phone can; the mini 2 is said to have much better GPS reception. No location information means?no SOS (other messages can be sent without location information if you choose). It may also happen that the path to the Iridium satellite is blocked; think about a deep valley, dense tree coverage, ... - on a typical hike in the Sierra sending tracking information every ten minutes it may typically happen more than once a day that a tracking point cannot be sent because of such reason.
?
Under favourable conditions a message goes out within seconds; but it may also need an hour sometimes, in the evening in the tent between trees in a valley.
?
Henning
?
Gesendet:?Freitag, 23. August 2024 um 05:41 Uhr
Von:?"Peter Klein via " <pklein95014=[email protected]>
An:?[email protected]
Betreff:?[JMT-groups.io] GPS SOS routing and delay
This isn't strictly JMT-related, but hopefully acceptable anyway.
?
I was reading an article about a Death Valley employee who went for a hike,
had some route confusion, ran out of water and had to SOS on his Garmin.
Excerpt below.? My question is, what is the routing of an SOS to explain
why it was 1:40 between pushing the button and the cognizant NPS et al
receiving the message???
?
I read another article about the hiking group that found the remains of
Julian Sands on Mt. Baldy.? They hit the SOS button and had a response?
in 8 mins. (which I thought was pretty amazing).
?
The DV excerpt:
?
"By 4:30 p.m., his water bottle was empty, and “heat and dehydration caught up with
him,” officials said in the news release. That’s when he fainted and fell.
“After an unknown period of time, he woke up bruised and realized it was time to
call for a rescue,” the news release read, noting he used the SOS function on his
Garmin tracking device at around 6 p.m. to get help.
NPS rangers and the Inyo County Sheriff’s Office received the call at 7:40 p.m."

--

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