Did they have man-portable GPS units in 1984

[Alpo]

According to wiki, the first GPS satellites were launched in 1978.

 

In the book I am reading they are in Antarctica, and are having trouble finding their way. They came off a nuclear submarine. If portable GPS units existed at that time (book was written and taking place in 1984) it seems like a nuclear submarine would have them.

 

They obviously are not using them in this story, but it just got me to wondering if it would have been available.

[Subdeacon Joe]

https://onlinemasters.ohio.edu/blog/the-evolution-of-portable-gps/

 

https://www.pcworld.com/article/2000276/a-brief-history-of-gps.html

 

Quote

1985 The government contracts with private companies to develop “airborne, shipboard and man-pack (portable)” GPS receivers.

1989 After years of testing, the Air Force finally launches the first fully operational GPS satellite into space. The Air Force had planned to launch the satellite on the Space Shuttle, but changed its plans after the Challenger disaster in 1986 and used a Delta II rocket instead.

1989 Magellan Corporation claims to be the first to market in the U.S. with a hand-held navigation device, the Magellan NAV 1000.

1990 Fearing military adversaries might use the GPS system to advantage, the Defense Department decides to deliberately decrease the accuracy of the system.

 

[Pat Riot]

Here is some interesting information on GPS Selective Availability. This was the offset system originally implemented in the GPS System so that adversaries of the US couldn’t effectively use GPS for nefarious reasons, like bombings and such. 
I had read that Bill Clinton had it removed when there was a large offset in the system and rescuers couldn’t find some lost Boy Scouts and someone lost their life. If that was the reason I don’t see it here, but in the links there is one document that mentions outdoor sports and the use of GPS. 

 

https://www.gps.gov/systems/gps/modernization/sa/

[Sedalia Dave]

Portable units existed at that time frame. However, it was not called GPS it was known as "Transit".

Transit was the precursor to GPS as we know it today. By the mid 80s single channel units were being produced that could have been transported over land if you brought along a big enough battery to power it. By today's standard accuracy would have been poor with a single fix only being accurate to about 400 meters. By averaging several fixes sub-meter accuracy was possible.

 

Below is a chart showing the relative accuracy of navigation systems.

 

  

 

Transit (satellite)

 

The below is a PDF copy of an article printed in the Johns Hopkins APL Technical Digest from 1984

 

The Navy Navagation Satellite System Transit.pdf

 

 

Picture of a low cost receiver available in the mid 80s

[Henry T Harrison]

It took me less than thirty seconds to google the answer to your daily cry for attention 

[Sedalia Dave]

MX 4102 Transit Satellite Navigator

 

MX 4102

 

Background

When Sputnik was put into orbit in 1957 some scientists at the Johns Hopkins Applied Physics Lab came up with the idea of using the doppler shift measured on the ground to solve for the 3 dimensional position of the receiver.  This required a satellite that transmits it's orbital elements.  There are a number of papers on the JHAPL Legacy of Transit web page.  The Navy Navigation Satellite System, as it was officially known, was designed mainly to allow the inertial navigation system on Polaris nuclear subs to be updated.

The very first Transit receiver took up about a dozen six foot high rack cabinets.  The receiver for the Polaris sub was in two cabinets designed to fit through the hatch as so were narrower than a normal relay rack.  The transistor had just come out and integrated circuits were non existent when the Transit satellite system went into operation.  By the time Magnavox built the MX 4102 integrated circuits were common, hence it's small size and much lower price than the very expensive early Transit receivers.

The MX 4102 was designed by Magnavox, Torrence, CA (now Leica Geosystems Group) for use on pleasure boats and since there can be a number of hours between Transit fixes it includes dead reckoning to keep the position updated.  This requires external compass and speed inputs from any number of the common types of sensors used abroad ships and the appropriate interface options for the MX 4102.

The MX 4102 uses a oven controlled oscillator (OCO) marked:
Electronic Research Company
Model EROS 800-MA-97
Mfg. p/n 626358-1 B
Freq 5.00 MHz
s/n 11703
Date 89-17

This is oscillator has a short term stability of 1E-10, equivalent to rack mounted lab type standard oscillators.  A high stability oscillator is needed to measure the doppler curve and to set the receiver tuning offset to account for the doppler shift of the carrier on the low orbiting Transit satellites.

 

Manuals

The Navigator's Manual and the Installation and Service Manual are dated June 1989.

 

Power

The unit operates from 10 to 30 Volt Dc power with positive going through the fuse.  the current is just over 1 amp at a cold start and decreases to about 0.8 amps after the oscillator oven has warmed up.

 

Operation

By setting the approximate position, date and time by pressing INIT repeatedly the receiver can start searching for signals.  When the signal strength at 400 Mhz gets above some threshold the receiver starts looking for the digital modulation.  Now when there is no active satellite or I don't have a high enough antenna gain the receiver beeps and displays no fix (NFX).  Apparently this receiver does not use the signal at 150 Mhz, only the 400 Mhz signal.  This means that the corrections for ionosphere refraction are either approximated or not used.

The front panel has a Vacuum Fluorescent Display (VFD) with buttons below and to the right so the VFD can act as a menu system.  In addition there are a couple of membrane keyboards, one with specific labels related to functions and the other with digits for numerical input.

 

Satellites

On 1 Jan. 1997 all the Transit satellites were turned over to the Navy Ionospheric Monitoring System (NIMS) and no longer use the Transit data modulation.  Instead they now use a different modulation that's a classified NIMS format.  These satellites are in a fairly high orbit and will stay there for a very long time, i.e. they will not decay and fall to Earth like a low orbiting satellite.  But they are all now very old and so will cease to operate electrically when failures take them off the air.  
The primary navigation frequencies are 149.985 and 399.970 and telemetry on 136.650 MHz.

[Sedalia Dave]

21 minutes ago, Henry T Harrison said:

It took me less than thirty seconds to google the answer to your daily cry for attention 

 

Your 30 second google search wouldn't have really answered his question. and in actuality you would have been wrong.

 However those of us that are curious and want a detailed answer would have discovered that Yes it would have been possible to have access to a man portable satellite based navigation system within the time frame of the story.

 

This is the Saloon and in getting a detailed answer I wouldn't have discovered that a satellite based navigation was first operational in 1964.

 

Personally I find Alpo's questions beneficial as they often lead to tangents and those of us that have the inclination can broaden our horizons by following the thread as it meanders along. 

 

If you don't like his questions why do you read his posts?

[Pat Riot]

I met a guy 2002 / 2003 whose job it was to use GIS - Geographic Information System, to locate items or designate the location of utilities, manholes, electrical boxes, electrical poles, etcetera… for Orange County CA. They were developing maps for all their utilities locations throughout the county. His GIS unit was about the size of a 2 slice toaster. It made my Magellan Meridian “Gold”, the highest tech civilian GPS available at the time, look like a flip phone compared to a smartphone today. 
A few years ago I met a lady in Wilsonville OR doing the same job. Her GIS unit looked like a large digital multimeter. 

[J.D. Daily]

7 hours ago, Sedalia Dave said:

MX 4102 Transit Satellite Navigator

 

MX 4102

 

Background

When Sputnik was put into orbit in 1957 some scientists at the Johns Hopkins Applied Physics Lab came up with the idea of using the doppler shift measured on the ground to solve for the 3 dimensional position of the receiver.  This required a satellite that transmits it's orbital elements.  There are a number of papers on the JHAPL Legacy of Transit web page.  The Navy Navigation Satellite System, as it was officially known, was designed mainly to allow the inertial navigation system on Polaris nuclear subs to be updated.

The very first Transit receiver took up about a dozen six foot high rack cabinets.  The receiver for the Polaris sub was in two cabinets designed to fit through the hatch as so were narrower than a normal relay rack.  The transistor had just come out and integrated circuits were non existent when the Transit satellite system went into operation.  By the time Magnavox built the MX 4102 integrated circuits were common, hence it's small size and much lower price than the very expensive early Transit receivers.

The MX 4102 was designed by Magnavox, Torrence, CA (now Leica Geosystems Group) for use on pleasure boats and since there can be a number of hours between Transit fixes it includes dead reckoning to keep the position updated.  This requires external compass and speed inputs from any number of the common types of sensors used abroad ships and the appropriate interface options for the MX 4102.

Fairchild Semiconductor produced the 1 st integrated circuits.  The 1st was a darlington pair.  Followed  by a operational amplifier.  The introduction was in the early 60's. early enough to be used in the AN/TPS 25 radar.*  The 1st microprocessor on a chip was introduced by Intel in 1971.  Before that a CPU required multiple IC's or discrete semiconductors & resistors on a printed circuit board.

*I was given a box of semiconductors, Fairchild darlington pair & op amp IC's by an AN TPS 25 crew when the 25th ID redeployed to Schofield Barracks in 1970-1971.  They didn't want to go through the hassle to account for inventory stuff not on the TO&E.

[Henry T Harrison]

12 hours ago, Sedalia Dave said:

 

Your 30 second google search wouldn't have really answered his question. and in actuality you would have been wrong.

 However those of us that are curious and want a detailed answer would have discovered that Yes it would have been possible to have access to a man portable satellite based navigation system within the time frame of the story.

 

This is the Saloon and in getting a detailed answer I wouldn't have discovered that a satellite based navigation was first operational in 1964.

 

Personally I find Alpo's questions beneficial as they often lead to tangents and those of us that have the inclination can broaden our horizons by following the thread as it meanders along. 

 

If you don't like his questions why do you read his posts?

To give him the attention that he so craves. If he really wanted to know the answer to the question he would google it himself 

[Michigan Slim]

23 hours ago, Pat Riot, SASS #13748 said:

I met a guy 2002 / 2003 whose job it was to use GIS - Geographic Information System, to locate items or designate the location of utilities, manholes, electrical boxes, electrical poles, etcetera… for Orange County CA. They were developing maps for all their utilities locations throughout the county. His GIS unit was about the size of a 2 slice toaster. It made my Magellan Meridian “Gold”, the highest tech civilian GPS available at the time, look like a flip phone compared to a smartphone today. 
A few years ago I met a lady in Wilsonville OR doing the same job. Her GIS unit looked like a large digital multimeter. 

That was early in the push to better map utilities in the GIS systems around the country. Most utility infrastructure installed today includes the GIS locations from the get go. It's very time consuming to build the database on existing systems. The lucky ones have that one employee that started when Pluto was a pup that remembers where this or that water line went in! 

[Cholla]

Lets not forget the LORAN system.  I was stationed on a LORAN base in Hawaii in 1979-1980. Ships and planes used LORAN to get a location fix.

[Colorado Coffinmaker]

Nuclear Submarines used and still use Inertial Navigation systems.  GPS Doesn't work through several hundred feet of water.  If a confirmation of position fix was needed, the Submarine came to periscope depth and used the periscope for a Star Sighting or a Sun Sighting.

 

When I was first in the military, land navigation was with a map and a compass.  Let us remember, without a map containing Longitude and Latitude, receiving GPS L&L grid coordinates was/is actually useless information. Of course, today, that "map" can be digital with a display. 

[Michigan Slim]

22 minutes ago, Cholla said:

Lets not forget the LORAN system.  I was stationed on a LORAN base in Hawaii in 1979-1980. Ships and planes used LORAN to get a location fix.

My folks used it on Lake Erie while walleye fishing.

[Ozark Huckleberry]

Was it just me, or were there any other former aviators who tensed just a bit at the phrase, ‘man portable’?

[Charlie Harley, #14153]

Alpo,

I get a kick out of your ponderings and the discussions they generate.  You don’t stop being you.

[WOLFY]

We had Loran in the 80s (shipboard).  IIRC GPS didn’t really emerge until after the storm (90s).

[BLACKFOOT SASS #11947]

Sometime in the '80's LORAN  C was developed and it worked really well,  was used in airplanes and on the water also.  I fished out of Galveston Tx and saved a lot of fuel with LORAN C.  Before C was developed we depended on dead reckoning.

 

Blackfoot

[Charlie Harley, #14153]

2 hours ago, WOLFY said:

We had Loran in the 80s (shipboard).  IIRC GPS didn’t really emerge until after the storm (90s).

GPS was in its infancy but definitely deployed in Desert Storm. 
 

The Battle of 73 Easting was largely enabled by GPS. American forces could do a coordinated attack in the featureless desert while the Iraqis basically had only dug-in positions and couldn’t move. 
 

https://en.m.wikipedia.org/wiki/Battle_of_73_Easting

[Uno Mas SASS #80082]

I did support for a friend's Baja 500/ 1000 racer in the early '90s.  I found the GPS satellite constellation wasn't sufficient to provide constant navigation. Plus, with those early units, it was all waypoint navigation - as the crow flies. Difficult for the guys in the buggy confined to meandering Mexican goat-paths.      

We have it SOOOOOO easy today, with turn by turn navigation to addresses. 

[WOLFY]

3 hours ago, Charlie Harley, #14153 said:

GPS was in its infancy but definitely deployed in Desert Storm. 
 

The Battle of 73 Easting was largely enabled by GPS. American forces could do a coordinated attack in the featureless desert while the Iraqis basically had only dug-in positions and couldn’t move. 
 

https://en.m.wikipedia.org/wiki/Battle_of_73_Easting

 

i should have written GPS didn’t emerge into civillian use until after desert storm.  i do not recall when gps devices actually became “handheld”.

[Dead River Den, SASS#915]

At our field station we started using plgers they were a military handheld gps unit in about 1992 or so, they were about the size of an  older cordless phone, the screen read lat/long coordinates, we use to have to send them out every few months to be reencrypted, the incription increased the accuracy to something like within a few meters.