we need an interface between the g1000 and the df unit

[starshippe]

. . it would be entirely too cool if someone developed an interface between these two. the df units, the df517 and the rt600, both have bi-directional rs 232 communications capabilities. a wee bit of software and presto, we would have the ability to deliver df info directly to the g1000 display.

. . with the real estate available on the display, one would not need to page through information. variations in the presented display could be done in software, and control of scanning functions, for instance, could also be done from the display.

. . i can imagine an automatic triangulation feature that would use the current gps position of the aircraft, and the relative bearing from the df, to plot lines of position. once the system gathered several of these lop's, it could calculate the position of the elt. it could then send the position back to base using the packet interface to the cap fm radio. ok, i'm getting ahead of myself.

. . with the addition of an analog input circuit or two, the older l-tronics units could be used. no more tapping the meter to make sure its not stuck. signal strength plotted as a function of heading and position. 

. . how cool would that be??

. . ok, i'm not sure that all of the i/o information is available, but it could be made available by rho theta.

just a thought,

bill

[Check Pilot/Tow Pilot]

Here is my Friday answer: 

We already have an interface between the g1000 and the DF gear, it's called the Mission Observer 

The Mission Observer, or MO for short, uses a far superior optical circuit, and is a true multi-purpose device.  Able to not only provide <sometimes correctly> DF interpretation, but also can be utilized to provide coffee <although short-circuits do result if over utilized for this purpose>, can serially read a checklist, can serially, one tortuously slow bit at a time, fill the baggage buffer, and can utilize massive parallel processors to identify every pilot bit error, and ensure that the pilot is made aware of these bit errors, when other Pilots are near.

The MO can also oversee through sequential clock gating the generally random flow of electrons flowing through the Mission Scanners much smaller and disorganized optical circuit.

So why do we need an analog circuit again? 

[Major Lord]

The idea is fine in principal, and all the communications protocols are open-source, but the cost of getting a converter to translate data and getting the device approved at every level would be a gonad-buster. With the right software in the G1000, one aircraft could orbit a suspected signal and plotting all the data ( Aircraft position, bearing to target, altitude, and topography, amongst others) a highly accurate probable position could be calculated. This of course is already being done in a variety of RDF systems, but it would be swell if it could be done with a ten buck adapter!

Major Lord

[starshippe]

. . lmao, ok i understand about the mo. but, i was hoping to include in this project the replacement of all of the df517s in the fleet. they can only receive the first two 406 channels, 406.025 and 406.028. all the new cessnas are being shipped with elts that use "newer" frequencies in the band. yes, there is a good possibility that we can be sent on 406 epirb missions, with the df receiver in the aircraft unable to receive the transmitted 406 signal. as the different manufacturers of elts and epirbs fill up the available 025 and 028 slots, they start using the newer allotted frequencies.

. . heres a link to the official document, the table of frequencies is in appendix h, table h.2.

http://www.cospas-sarsat.org/images/stories/SystemDocs/Current/t12oct28.10_completedocpart2.pdf

. . most of the document is a bit "sticky," but the table is easy reading.

. . yes, i know there is a 121.5 homing beacon aboard most of these units, but its lower powered than the older models. the theory of the high powered 406 data burst defines the 406 system.

. . the two analog input circuits would be for the two metering signals on the l-tronics. i'm still very fond of these units, as they have never been susceptible to interference from local fm radio stations, as both of the rho theta units are. (the df517 was built by rho theta and marketed by becker.) sadly, many of these older units do not receive the maintenance they deserve. 

. . it seems that, if we can spend three million dollars to paint a cap emblem on the hood of a nascar racer, we can afford to spring for some r&d money to bring the one piece of equipment that most distinctly defines the aircraft as a "search and rescue" platform, into clear view of the aircrew. i would have used the archer expenses as the example, but only god knows how much that cost.

bill

[Robborsari]

I will be happy just to keep getting beckers in the aircraft.  Has anyone successfully DF'ed a 406 from the data burst?
We have had a few that we circled and circled and drove around but never picked up the 121.5.  The 406 blinking hold was not enough to lead us to the right spot.

[starshippe]

. . yes, with time, our aircrew did resolve a position on a 406 beacon using the data bursts. it had been recently buried in a land fill in jesup, ga. i could not hear the 121.5 until i was within about 50 feet.

. . i think that a mk4 sniffer could allow ground teams to df on 406. i have asked him to build one, but have not heard anything back. the mk4 varies the pitch as a function of signal strength. if the unit slews quickly enough, swinging the antenna should define the direction. i already have a small arrow antenna for 406.

. . please understand that the becker 517 only receives the first two 406 frequencies. we need to get them all changed out to the rho theta rt 600. cessna was using some of the newer frequencies as early as mid last year.

. . the scanning functions of each of these units is for the most part not understood. and they differ significantly. i will try to put some info together. i did for the ga wing conference, but they parked the presentation in a spot on the web site that required a logon and password. the 517, in the scan mode, will *never* move off of 406 until it hears a data burst.

bill

[MikeD]

The idea is fine in principal, and all the communications protocols are open-source, but the cost of getting a converter to translate data and getting the device approved at every level would be a gonad-buster. With the right software in the G1000, one aircraft could orbit a suspected signal and plotting all the data ( Aircraft position, bearing to target, altitude, and topography, amongst others) a highly accurate probable position could be calculated. This of course is already being done in a variety of RDF systems, but it would be swell if it could be done with a ten buck adapter!

Major Lord

Would you believe two $10 adapters?  </Maxwell Smart Voice> 
Putting this in the G1000 would be cost-prohibitive, due to the certification issues.  There aren't any with pulling the data from both that and the DF unit and fusing it on a cheapie netbook, or maybe an Android tablet that can pull in serial data over USB (not gonna happen on an iPad). 

To do a slight thread-jack, I've seen a lot of good ideas on this forum that just need some people with technical skills to work on then some.  I know we have some cadets and SMs who are going to school for technical things, and it might make a nifty senior design project or independent study.  Is anyone keeping a single list of "cool tech toys CAP would like to have" somewhere?  WE could make at least some of these happen, if we got a couple people together and were able to focus on them some. 

[Major Lord]

MikeD,

Put me on the RPV project , and the APRS over CAP radio committee!

Major Lord

[starshippe]

   we did some aprs over the cap fm radio back in '94. i had a magellan gps, about the size of a brick, but not as thick, and a kc85, which was a knock off of the radio shack model 102. we hooked up the rs232 lines and stuck a bit of basic software in the laptop, which sampled the data from the gps, extracted lat and lon, and pushed it out to the tnc. we were able to track the aircraft from mission base with no problem. after a bit, we just stopped using it.


bill