Topo maps with lat and long grids.

[SARJunkie]

The Florida side of the mission, when they reported the targets via the State 800MHz system were in USNG. all FL operations were in USNG.

[chief2]

That was if the 800mhz worked, which most of the time it didn't because they called me on the Daphne Rpt and gave me all their reports in lat and lon. So not all Florida operations were using USNG, All aircraft from GA, AL, La, MS, NC, FL, and GLR gave me their reports in Lat and Lon.

[Eclipse]

Don't you love how facts get in the way of assumptions?

[SARJunkie]

wow...

[Spaceman3750]

... everyone went to USNG!!!!!!!!!!!!!!!

Today I'm here to talk to you about USNG. Quite frankly, it's simply magical and revolutionary^TM.

Sorry, I had to do it.

[chief2]

There have been many reports in Electronic/radio mag. about the failure of the 800 mhz systems, when it is used in the area of long neddle pine trees, the neddle's appear to set up a harmonic in the 800 mhz range, killing the use of the system. A private amb. service in Lower Al (RM) attempted to use it, it was a total failure and had to resort to the use of a VHF system.

[Eclipse]

... everyone went to USNG!!!!!!!!!!!!!!!

Today I'm here to talk to you about USNG. Quite frankly, it's simply magical and revolutionary^TM.

Sorry, I had to do it.

You win - epic - seriously!

[SARJunkie]

There have been many reports in Electronic/radio mag. about the failure of the 800 mhz systems, when it is used in the area of long neddle pine trees, the neddle's appear to set up a harmonic in the 800 mhz range, killing the use of the system. A private amb. service in Lower Al (RM) attempted to use it, it was a total failure and had to resort to the use of a VHF system.

yes, because there are soo many pine trees 5 miles off shore!

[chief2]

I take it your command center was also 5 miles off shore

[SARJunkie]

what does pine needles have to do with Comms and USNG Lat Long?   Im not trying to be a smart ass...  just currious

[chief2]

If you read the prev post about using the Foresty 800 mhz system, you would understand why it does not work around long neddle pines trees.  That is why almost all of FD and PD depts are leaving the 800 mhz systems in the south where there is a lot of long neddle pines and moving to the 700mhz systems. and that is why it did not function properly during dwh and the Florida aircraft diverted back to using an established vhf rpt system, All aircraft in the dwh mission, FL, AL, GA, Tn, La, Ms, NC, and GLR all used the standard lat lon system per the request of the US Coast Guard. and I have that on the work sheets they sent out. Also all vessels working the spills and booms used the lat lon system as I had constant communication with them also

[SarDragon]

To add more - pine needles contain a significant amount of moisture, which conducts electricity. I measured the resistance of several 3" long pine needles, taken at random directly from the tree, and the end-to-end resistance was about 4 megohms.

The wavelength for 800 MHz is 14.8", so one of these needles approaches being 1/4 wavelength, and a potential antenna.

The Navy had significant problems with the radars on their maritime patrol/ASW a/c early on because of "salt return". The salt spray over the ocean would cause a significant return on radars tuned to frequencies having wavelengths in the neighborhood of multiples of the dimensions of airborne salt crystals. Retune the radars - problem goes away.

YMMV.

[chief2]

Pine neddles down here on the coast run an easy 14" in length

[Spaceman3750]

To add more - pine needles contain a significant amount of moisture, which conducts electricity. I measured the resistance of several 3" long pine needles, taken at random directly from the tree, and the end-to-end resistance was about 4 megohms.

The wavelength for 800 MHz is 14.8", so one of these needles approaches being 1/4 wavelength, and a potential antenna.

The Navy had significant problems with the radars on their maritime patrol/ASW a/c early on because of "salt return". The salt spray over the ocean would cause a significant return on radars tuned to frequencies having wavelengths in the neighborhood of multiples of the dimensions of airborne salt crystals. Retune the radars - problem goes away.

YMMV.

I understand that 1/4 wavelength is ideal for an antenna, but does it HAVE to be 1/4 wavelength to become an antenna?

[SarDragon]

Not at all. Multiples of 1/4 wave work just as well. I was just pointing out the reasoning behind that particular problem. I thought I clarified the multiple wavelength part when I discussed salt return.

[SARJunkie]

First off, the system is NOT a forestry system.  Being a professional RF guy, why would forestry even  use 800? that's kind of stupid!

The problem with the 800 system in deepwater, is the crews couldn't follow directions.  there were several other agencies using portables in aircraft that had no problem with the system. 

The system uses both 800 and 700, so your theory of 800 pine needle interference would not apply here.

I routinely flew 30+ miles offshore with an 800 portable in a Cessna or helo, and had no problems.

When you spend 30 min with the crew, give them a 'cheat sheet' on the radio and them have them demo it to you, you would think that they would understand.  approx 40% of the crews just couldn't handle it!

Its not an issue of propagation, or RF, or the system not working.  its 100% operator error.

I can also tell you for a FACT that the coordinate system used on the 800 system was USNG, for the "State Mission"

[ammotrucker]

If you read the prev post about using the Foresty 800 mhz system, you would understand why it does not work around long neddle pines trees.  That is why almost all of FD and PD depts are leaving the 800 mhz systems in the south where there is a lot of long neddle pines and moving to the 700mhz systems. and that is why it did not function properly during dwh and the Florida aircraft diverted back to using an established vhf rpt system, All aircraft in the dwh mission, FL, AL, GA, Tn, La, Ms, NC, and GLR all used the standard lat lon system per the request of the US Coast Guard. and I have that on the work sheets they sent out. Also all vessels working the spills and booms used the lat lon system as I had constant communication with them also

First off cheif2 you may have talked to FLWG aircraft for either the Mobile mission or the State mission.  I will agree that if FLWG aircraft were on the Mobile mission checking in with you they were instructed to communicate in Lat/Long.  So I would agree that from your perspective they were using the lat/long system. 

While the State mission was required to use USNG.  This was to be transmitted on the 800Mz system.  The aircrews that were on this mission were also told to communicate with you as a precaution, for the act of deconfliction of aircraft.  Again, you and Mobile and USCG were talking with lat/long so the aircrews were instructed to talk in lat/longto you. 

While SARJunkie point out "When you spend 30 min with the crew, give them a 'cheat sheet' on the radio and them have them demo it to you, you would think that they would understand.  approx 40% of the crews just couldn't handle it!

Its not an issue of propagation, or RF, or the system not working.  its 100% operator error."

I will also agree with his asessment. 

As with SARJunkie's asessment that all State agencies have been mandated to use the USNG, I am not sure that is the case.  What I can say with certainty is that any Agency that works with DEM as a primary or secondary agency MUST use USNG.

[Eclipse]

Pine neddles down here on the coast run an easy 14" in length

You obviously have played knifey-pine needle before...

[starshippe]

. . i have been in es for a few decades, and until this thread, had not heard of usng. i do not think the gps in our aircraft allows us to select usng as a coordinate system. i searched through the 536 pages of the g1000 manual, and did not find a reference to it.
. . when anyone says, we are all going to the usng coordinate system, are they also speaking of our cap aircraft? do we have any cap aircraft whose gps allows the selection of usng as a coordinate system?

thanks,
bill

[Thom]

. . i have been in es for a few decades, and until this thread, had not heard of usng. i do not think the gps in our aircraft allows us to select usng as a coordinate system. i searched through the 536 pages of the g1000 manual, and did not find a reference to it.
. . when anyone says, we are all going to the usng coordinate system, are they also speaking of our cap aircraft? do we have any cap aircraft whose gps allows the selection of usng as a coordinate system?

thanks,
bill

Bill, don't panic! No one is planning to change the way we do business in terms of navigation and flying, that will remain Lat/Long for the foreseeable future.

What is coming (sooner or later...) is that under the Federal system of SAR, particularly with the National SAR Committee, they have standardized on a number of different systems to be used, depending on whether you are Land SAR, Airborne SAR, Maritime SAR, etc.

As part of this effort, they have standardized on USNG as the primary system to be used by Land SAR responders. And, Lat/Long is the standard primary system for Airborne SAR (whew!).

Unfortunately, they also decided that it was the responsibility of the Airborne folks to translate their Lat/Long info into USNG when interoperating with Land SAR folks.

So, eventually, at least some of our Mission Base staff will need to understand USNG and Lat/Long so they can translate and relay to the Land SAR organizations. It would probably be a good idea to eventually train the aircrews in how to do this so that every message doesn't need to bounce through Mission Base when talking a Land SAR group into a target.

The Big Questions: How soon will Land SAR organizations adopt USNG, how uniformly will they adopt it across multiple organizations, and how soon do we need to be ready to interoperate with folks using it? I'm not taking any bets, the odds are still swinging wildly from month to month, and varies from one organization to another.

Here's a pic of the National SAR Committee's Matrix of Coordinate Systems, it lays it out pretty well.
And, here's a link to a short, but useful document: http://lawgcap.org/lawg-content/ladocs/SAR-Coordinate-Systems.pdf

Bonus: The National SAR Committee also picked Degrees with Decimal Minutes as the standard format for Lat/Long between organizations when Lat/Long is used, so hopefully, eventually, we can get most folks switched over to that from DMS.





Thom