DAGR - Defense Advanced GPS Receiver

The MicroDAGR (pdf) and it's civilian version the MicroGuide (pdf) were introduced in 2013. These appear to be Android operating system based much smaller versions of the DAGR. BUT . . .  they do not have the 15 pin VGA type connectors and instead use some USB or other connector.  This is a problem because of interfacing to other hardware devices.  USB-C came out in 2014 (Wiki) so I doubt it's part of the Micro/DAGR and that's also a problem.

Firmware Versions

GPS Signals (Wiki)

M-Code

It turns out that Russia has jammers with a range of maybe 10 miles  in Ukraine that prevent the classical military GPS systems (L1, L2, C/A, P(Y)) from working.  The M-code may be a solution.

Crystal Frequencies

The 10.23 MHz crystal and it's harmonics are shown in the table above and in the illustration below.  Also shown below is the 128^th harmonic of the 10.949297 MHz crystal used in the Rockwell Collins GPS receivers (see Polaris Link below) in order to center the LO between L1 and L2 so that a single LO can be used for both frequencies with the same IF frequency of 173.91 MHz.
 

Major Influences

• When GPS was a proposal it would have failed to be funded if it were not for the Nuclear Detonation Detection System (Wiki). (First launch 1978 Feb 22, so the proposal stage may have been in the mid 1960s?)
  
• Prior to the 1 September 1983 shoot down of KAL007 (Wiki: President Ronald Reagan ordered the U.S. military to open their Global Positioning System (GPS) to civilian use.) GPS was a secret and stealth technology.  That's to say the signal on the Earth's surface is below thermal noise, so if you don't know where it is and how to demodulate it, you will not know it's there.
• Wiki: In the 1990s, the FAA started pressuring the military to turn off SA permanently and it was on 1 May 2000.
• The Safety of Life L5 signal, see above, is driven by the FAA.
  

DAGR (Polaris Guide)

Note case is a green color.

Polaris Guide HNV-1660 SPS Standard Positioning Service (SPS marked) Note case is gray.	PSN-13A DAGR Precision Positioning Service (PPS not marked) Note case is green.
Menu\System\About\Enter (HWver)\Enter as seen when Function Set is Basic. "Start Reprogrammer" is not an option here. Also see Applications & Jammer Finder	PSN-13A DAGR front removed (6 screws) This receiver does not power up at all. DOA
Menu\System\About\Enter (HWver)\Enter as seen when Function Set is Advanced -or- Menu\System\About\Enter (HWver)\<dn arrow (SWver)\Enter as seen when Function Set is Advanced "Start Reprogrammer" is an option here.	PSN-13A DAGR Top PCB open (1 screw) Notice two antennas since L1 & L2.
	PSN-13A Back Inside two antennas at top backed by combiner & RF amp has single coax to mother board.  Other coax is from external ant. Components on flex circuit are power supply filtering.
PSN-13A Motherboard bottom RF processing under metal top shields, Lowest metal shield is marked ARM. Near the lower left corner of the big black chip there's a Honeywell HMC1052 2-axis Hall bridge magnetic sensor.	PSN-13A Motherboard top Small white socket is for front panel keyboard.

GB-GRAM (Polaris Link)

GB-GRAM

In addition to the handheld DAGR there is a 12 Channel printed circuit board version called the Ground Based - GPS Receiver Application Module (GB-GRAM).  Note a Ground Based application will have velocity, acceleration and jerk values much less than those encountered in air and space craft and a GPS can exclude the higher values making for a better solution.    More importantly GPS receivers rated for air or space usage have more ITAR controls on their distribution. The military DAGR and GB-GRAM are CCI items that can not be sold to civilians, but the Polaris Guide is the civilian version and the Polaris Link is the civilian version of the GB-GRAM.

Polaris Link p/n: 987-8760-002 New In Box (NIB)

Polaris Link p/n: 987-8760-002 Polaris Link p/n: 987-8760-002 Single antenna connector since L1 only

The Polaris Link 12 Channel SPS (Standard Positioning Service) board uses a Rakon 10.949297 MHz unit oscillator.

Documents

Appendix D contains the pin out for the 80 pin connector.

Classical PVT

Applications

While trying to see what was in the Applications menu of the Polaris SPS it jumped into Jammer Finder mode. 
That was because after a cold start the Function Set is "Basic".

In order to get access to all the Applications you need to change the Function Set to Advanced:
Menu \ Menu \ System \ Select Function Set \ Advanced.

Gun Laying System, Civilian: Azimuth Determination

This is listed first since it's the feature that I'm most interested in.  Wiki says: "Gun laying is a set of actions to align the axis of a gun barrel so that it points in the required direction."
Since both bearing and distance between the two locations is calculated this can be used as a surveying method. 
GLS will shortly be called Azimuth Determination for both the DAGR and Polaris.  This way it's OK for the Polaris to have Azimuth Determination.

Real Time Kinematic (Wiki: RTK) is the surveying term for a GPS receiver that tracks while it is being moved.  But in the surveying application there's a radio link from the base station to the rover and the actual position of the rover is known.  The North Finding system does not need to know the actual position of either point.

6181274 Satellite navigation receiver for precise relative positioning in real time, MIT, Jan 30, 2001, 342/357.04 ; 342/357.08 - is a similar patent but includes a radio link for code and carrier phase corrections.   The next generation Rockwell GPS receiver may have RTK capability, but it takes more channels since L1 and L2 must be on separate channels.

Single Receiver Method

Using a single DAGR with a survey grade GPS antenna  attached to the top of a pole over a stake and then moving it to another stake you can determine the bearing and distance between the stakes.  This would allow surveying using a single DAGR.  Accuracy of 3 mils (1 mil at 1 km = 1 meter, in NATO countries it's 1/6400 of a circle).  3 MILs is about 10 arc minutes of angle.  Note that the SIN(3 MIL) * base line length is an estimate of the error in the length part of the measurement.  In 100 feet that's about 3.5 inches radius.

The method used is covered in patent 5999123 and involves carrier phase tracking rather than differential corrections.  That's how they get such good accuracy.  Rockwell has a number of patents relating to the detection of carrier phase cycle slip and precision carrier phase tracking methods which would help in this application.  For example excluding some satellites from the beginning if they have carrier phase characteristics that make cycle slip hard to detect.

The accuracy can be improved by minimizing the time of the measurement because many of the error sources change at a slow rate.
The accuracy can be improved by using a long base line.
The above two accuracy improvements work against each other.  The longer the base line the more time it takes to move the receiver.

See zero baseline test results below for the Polaris Guide civilian receiver.

5999123 Time-relative positioning for static applications, Rockwell International , Dec 7, 1999, 342/357.08

This is a method based on tracking the carrier phase as a single receiver is moved from one stake to another.  The path between stakes does not need to be along a straight line, but the view to all the satellites being tracked must not be blocked.  i.e. it does not work near buildings.

Patent Number	Title	Issue date
5021792	System for determining direction or attitude using GPS satellite signals	Jun 4, 1991
5266958	Direction indicating apparatus and method	Nov 30, 1993

Kit, Azimuth Determination Single DAGR Receiver 987-6279-002 (NSN N/A)

The AD single receiver kit is used in the calculation of the azimuth Installation mount, pole clamp for installation mount, antenna, antenna cable and bag are included

Dual Receiver Method (Sub Mil)

The Master/rover is programmed.  The Slave/base GPS control panel does not need to be operated.

2022 April - The antenna/pole adapter so far is hiding from me.  It's the missing part in order to do the dual receiver method in the field.

	The requires a couple of Antenna/Pole Adapters NSN: 5985-01-527-3372 p/n: 987-6315-001 The large thread at the bottom center of the RA-1 is NOT a standard tripod 1/4-20 thread but is instead a 10-32.  This makes it a problem to mount the RA-1 on a survey range pole, hence the above adapter.  Let me know where to get the adapter.
Using AT-575 survey antennas	First generation system used AT-575 antennas. now using RA-1 antennas From TM 11-5820-1172-13 pdf page 435
Kit, Sub-MIL Azimuth Determination (AD) Dual DAGR Receiver 987-6280-002 (NSN 5985-01-549-7219) The sub-mil AD accessory kit is used to increase accuracy over the AD method of calculating the azimuth  Antennas, antenna cables, quick disconnect DAGR-to-DAGR cable and case is included	Note the cable shown is a single piece, not a quick disconnect.
DAGR-to-Survey Antenna Cable (9.5 inches with TNC connector) 987-5015-002 (NSN 5995-01-549-8449) For use with survey antenna (013- 1962-040) TNC plug (M) and right angle SMA plug (M) 9.5 inches
DAGR-to-Survey Antenna Cable (19 inches with TNC connector) 987-5015-003 (NSN TBA) For use with survey antenna (013- 1962-040) TNC plug (M) and right angle SMA plug (M) 19 inches
Quick Disconnect Cable Socket 988-7042-002 NSN 5995-01-549-8447 The DAGR/DAGR/PLGR cable provides for connection between two DAGRs or between a DAGR and a PLGR 15-pin D-sub plug (F) 4-pin circular socket (F) 20 inches Transfer data includes: setup, waypoints, routes, alerts, time, satellite data, position data and maps Intended use with azimuth determination system (987-6280- 002)
Quick Disconnect Cable Plug 988-7043-002 NSN 5995-01-549-8451 CAGE: 13499 Mfr. 47Q1 0948 The DAGR/DAGR/PLGR cable provides for connection between two DAGRs or between a DAGR and a PLGR 15-pin D-sub plug (F) 4-pin circular plug (M) 40 inches Transfer data includes: setup, waypoints, routes, alerts, time, satellite data, position data and maps Intended use with azimuth determination system (987-6280- 002) Belden 9927 (0.209", 5.31mm OD) 4-contact Lemo type	DB-15 J1 J2 Lemo 2 S_Mux 1PPS_IN_RTN 1 2 14 COM3_XMT COM1_XMT 3 15 COM3_RCV COM1_RCV 4 This wiring seems odd.  I was expecting DB-15 pin 3 (GND) not the 1PPS return DB-15 pin 2.  Maybe that was a problem with this cable?
Seco 5111-00 Quick Disconnect GPS Prism Pole Adapter

This provides about the same accuracy as the AG8  gyroscope + Theodolite (or Wild ARK-1 gyro) system but is much more rugged, smaller, lighter and less expensive than the fragile AG8.  But the AG8 does work in underground locations where there is no GPS signal so probably the gyro based systems are still being used for some applications.

In the dual receiver method you specify a walk time with the two receivers next to each other and cabled together so they can do a precision time sync.  After you have moved the rover to the out post and the walk time expires both receivers make and record a single measurement at the same instant.  Then when the rover GPS is brought back to the master GPS and they are cabled together,  an L1 carrier phase calculation is made to determine the difference between the master and rover locations.  The improvement comes about because both measurements are made at the same time.  In the single receiver method there is a time difference between the measurements.
Accuracy in the 0.5 mil area or around 1 arc minute of angle.

The slave receiver is left on the starting tripod and the master receiver is walked to the remote stake and stays there, accumulating data, until the preset walk time expires.  Then the master is returned to the base location and reconnected to the slave, where the computations are done to determine the remote stake distance and bearing.

During the walk between stakes a clear view of the sky must be maintained but the walk does not need to be in a straight line. Breaking lock with a satellite degrades the result and if less than 4 satellites it will fail the procedure.

Antennas for Azimuth Determination

They say survey grade external antenna(s) is (are) required for both methods.  
The first possible reason for the survey grade antennas is that when a lesser antenna, like the RA-1 is used multipath during the walk causes one or more satellites to break lock making the method non operational.  Survey grade GPS antennas typically have choke rings below the antenna to prevent multipath, but you could mount the RA-1 (or maybe the DAGR/Polaris) over a ground plane to achieve the same result.  The two (AT-575, AT-575 on SECO pole) antennas shown in the photo at left do NOT have choke rings.

A second possible reason is that   Maybe the reason has to do with keeping the antenna up above the person carrying it during the walk.  But that can be done using a pole and GPS mounting bracket.

In the manual illustration they show two of the RA-1 antennas being used, but the older photo shows a couple of AT-575 survey type antennas.

Dual Polaris Azimuth Determination

Menu \ Menu \ Applications \ Az Determination
A list of way points appears, just select the first one then press ENTER to get to the setup screen.
At this point if a data cable is connecting two Polaris receivers both screens show that Dual Receiver mode has started.
The walk time started at 35 seconds.

Polaris Azimuth Determination pages
To move between these pages you can use the up/down arrow or the Page/Quit keys.
The default units can be changed by pressing Enter and then selecting the sub-menu item to change the units.
I think the pages shown as Fig 10 through Fig 14 are the same for single or dual receiver modes.

Note the default units for everything are not what I'd like to see, so you might want to change them before making a measurement.  Although I was able to change them after the test was complete, but you may want to change them first so that you can see if the results make any sense as you go.

Dual Polaris GPS Azimuth Determination

Fig 10
Fig 11
Fig 12
Fig 13
Fig 14

First steps in Dual Polaris receiver Azimuth Determination.
The key thing is how many satellites are in view.  So choosing the time of day to make the determination is important.

Fig 1	My Polaris shows: Azimuth Determination  01-AD01 Status: Tracking: 2 of 10 Use [Enter] to continue Last Modified: -- New Polaris shows: Azimuth Determination in progress Do Not Move the Receiver (i.e. this is the base receiver) [Quit] to abort calculation
Fig 2	My Polaris shows Azimuth Determination  01-AD01 Status: Tracking: 4 of 9 Use [Enter] to continue Last Modified: --
Fig 3
Fig 4	My (rover) Polaris.  The rover is in control of the survey. The base Polaris just sits there.

DAGR & Polaris Az

It turns out that they work together to determine the azimuth and distance between two stakes.  This first test was done with an external antenna on each receiver sitting on a window sill facing South and the data cable left connected between the DAGR and Polaris throughout the test.

Fig 1 Polaris at left is rover.  Base unit is linked.	Fig 2 Use [Enter} upon Reaching Point 2	Fig 3 Reconnect Receivers to Complete Calculation.
Fig 4 Results of calculation. 0.01m should be 0.00 meters since the antenna was not moved.  So a 1 cm error.	Fig 5 Orienting Line This is a random number since there was no antenna movement.

 Triple Receiver Method?

This is NOT supported on any DAGR as far as I know, but may be on some systems, like on ships.
5021792 System for determining direction or attitude using GPS satellite signals

This is a system that uses three GPS receivers and three antennas. 
Maybe a future enhancement on the dual receiver method, i.e. 3 Receiver method
The antennas are used:
First in a straight line
Second two of them are interchanged
Third one of them is moved away from the line by the distance between the remaining two.

Patent Number	Title	Issue date
3766556	CHANNEL SWITCHING PHASE - for canceling IF non linearities	Oct 1973
4719469	Direction-determining system - two fast switched antennas and interferometry	Jan 12, 1988
4845502	Direction finding method and apparatus - two antennas on rotating platform are combined in balanced mixer	Jul 4, 1989
4881080	Apparatus for and a method of determining compass headings, Navy - uses two antennas, ant switch and one GPS receiver	Nov 14, 1989

Fire Support (DAGR: Target Location, Polaris: Waypoint determination)

The Polaris Guide WayPoint Determination application appears to be the same as the DAGR Fire Support application.

This was also supported with the PLGR.  By using a compatible Laser Range Finder cabled to the DAGR (or manual input of range, bearing and elevation angle to the target) you can get the coordinates of a target.  This requires that the Laser Range Finder sends at least the magnetic bearing and distance to the target and better is the addition the elevation angle.  So far I haven't found LRFs on the open market that have a range of more than about 1 km whereas the military LRFs may be good for 10 km.  The Vector binoculars that include Laser Range Finding, Magnetic Compass, elevation angle inclinometer and RS-232 data cost over $10,000 on the used market.  There are only a very few Laser Range Finders with RS-232 output.

An alternate way to get target location would involve taking multiple sightings from a different locations (maybe even from a moving vehicle) where you only know magnetic bearing and elevation angle.  Then triangulate the readings.  Note by using more than two sightings averaging can be used to improve the precision of the target location.  The DAGR does support multiple sightings of the same target.

There have been some tragic accidents when the soldier operating the DAGR called for fire support and instead of giving the target coordinates gave his own coordinates.

6064942 Enhanced precision forward observation system and Method, Rockwell Collins, May 16, 2000, 701/213 ; 342/118; 342/357.01; 342/357.06; 342/357.08; 434/1; 701/207 - employs multiple measurements to reduce the CEP

Patent Number	Title	Issue date
5736960	Atomic clock augmented global positioning system receivers and global positioning system incorporating same	Apr 7, 1998
5739786	GPS transfer initialization system	Apr 14, 1998
5757316	Attitude determination utilizing an inertial measurement unit and a plurality of satellite transmitters	May 26, 1998

Low cost astronomical orientation sensors are available that can tell you the magnetic bearing and elevation angle to any target.  For example the Clestron SkyScout or Mead mySKY.

Laser Range Finders

Vector 21	Vector Function DAGR 1 Gnd 3 Gnd 2 Trig na 3 Trig 5 Data 14 Tx 7 Data 15 Rx RS-232 9600 8N1 Data Format: Zdddddd[CS]<CR> Z: d: dist, a:Az, e: Elev; C: Compass err, R: Range err, M: Main board err	Vector 21 Binocular Interface Cable w/Remote Firing Button NSN: 6150-01-5657-440 p/n: 234-300-38V-0001 p/n: 300-38V-0001-00 was: CA/F-2.5-05R CAGE: 0UW80 Ashbury VECTOR 21 15 Pin Remote Fire DAGR/PLGR Cable Connectors: Vector: Fischer WSO 1031 A012-41+ DAGR J2: DB-15f
Vector IV

There are civilian LRFs made for golf and sporting applications with ranges up to about 1 km, most are a few hundred yards.  But there are also civilian LRFs that have long ranges.  Very few have data output that can couple to the DAGR/Polaris Guide.  Note:  The data format is not NMEA (Wiki), but a proprietary Leica format.
Vector 21 - Ashbury International, p/n: CA/F-2.5-05R - Vector 21 to PLGR/DAGR Interface Cable w/Remote Firing Switch (photo), Tact3-S Tripod "For use with devices equipped with a magnetic compass."
Leica Vector IV
Litton Mark VII - 7.3 x 18 day optics, 4 x 50 image intensifier, Nd:YAG laser, eye-safe 1.57 micron Riegl LASERTAPE FG21 - up to 2500 meters
The military LRFs typically have a max range of about 10 km.
AN/GVS-5 (MX-9838) Nd:YAG 1.06 micron) hand held fielded 1980 - Class 4 Non-Eye Safe, only usable in daytime
AN/PVS-6 Mini Eyesafe Laser Infrared Observation Set (MELIOS), only usable in daytime
MLR 30 - 20 km range, 1.064 microns
MLR 40 - 20 km range, 1.54 microns
LH30 - 80 m to 20 km
LH40C - erbium:glass laser, 1.54 microns, built in compass & inclinometer
Leica Geosystems ZVBA
Brashear LP MLRF 100 - 1.54 microns, mounts on personal weapons
AN/PEQ-21B Common Laser Range Finder (CLRF) - similar in magnification and field of view to the M-22 binoculars, built in compass & inclinometer, GPS interface
AN/AAS-37
AN/AAS-38 Nite Hawk
LRM 2500 CI - 2500 m, built in compass & inclinometer
LRB 25,000 25 km - 1.54 micron eye safe,

YouTube:  ACE3 MicroDAGR and Vector21 Tutorial | ArmA 3 - while intended for a video game I think the instructions also apply to the real Vector 2 and DAGR.

Close Air Support (CAS-9 Line Brief)

This is a DAGR only application.  The Search Grid application in the Polaris Guide is very different.
Needless to say calling for CAS must be done correctly to avoid fratricide.
See Ref 14.

The 9 Line items are:
1. Initial Point (IP),
2. Heading IP to Target,
3. Distance IP to Target,
4. Target Elevation,
5. Target Description,
6. Target Location (MGRS or ...),
7. Type of Mark,
8. Location of Friendlies,
9. Egress (Relative to Target).

Jammer Finder

While trying to see what was in the Applications menu of the Polaris SPS it jumped into Jammer Finder mode. 
That was because after a cold start the Function Set is "Basic".

In order to get access to all the Applications you need to change the Function Set to Advanced:
Menu \ Menu \ System \ Select Function Set \ Advanced.

	I'm guessing that this was because there were three Wi-Fi routers very close. Tried outside and still get Jammer Finder?
Polaris Guide Applications Menu when in Advanced Function mode	Advanced Function Set Applications on Polaris Guide: WP Calculation (same as DAGR Fire Support) Jammer Finder Az Determination (same as DAGR Gun Laying) Search Grid (mowing the lawn between two way points)
DAGR Applications Menu when in Advanced Function mode	Advanced Function Set Applications on DAGR: Fire Support (LADS Army.mil) CAS 9-Line Brief (Close Air Support, Wiki, Program Pacer Speak) Jammer Finder Gun Laying (Azimuth Determination)
	Advanced Function Set "About" on Polaris Guide Menu\System\About\Enter (HWver)\Enter as seen when Function Set is Advanced -or- Menu\System\About\Enter (HWver)\<dn arrow (SWver)\Enter as seen when Function Set is Advanced

Spoofing

Spoofing is very different than jamming (Wiki).  Jamming, when effective, prevents the authorized user from making use of the signal.  Spoofing sends false signals to the authorized user, which in the case of GPS will cause the location and/or time to be wrong.

GPSJAM.org - Ukraine with date turned off, so when you look.  World Map.
HackRF - HackRF One - Docs -
eBay search term: "Portapack H2 Mayhem Firmware" - Saymlove Electronic Store -
PortaPack -

Carrier Phase Data

Time

Differential Corrections

There used to be GPS receivers on the coastlines of waterways, operated by the US Coast Guard, transmitting differential corrections (Wiki) to improve the accuracy of GPS of ships in or near ports.  These were long wave  transmissions.  The long wave transmissions had a range on the order of 100 miles so only applied to a local area.  Another way to get the same correction data was to have a specialized GPS receiver, like the Ashtech Z12, that not only can receive and use the L2 phase information without knowing the crypto key for the L2 data, but also generates correction data that can be broadcast using UHF radios.  One name for this is Real Time Kinematic (Wiki).

Batteries

Comparing PLGRII and DAGR

Outdoors	Indoors
PLGRII External Antenna Jack The PLGRII external antenna connector is a waterproof type.  I expect the mating connector looks just like the plug shown here.  It's 6.17 mm (0.243") O.D.  Now to find out what it is. This is the same O.D. as the 75 Ohm SMB, but should be 50 Ohms and the SMB male pin does not look to be in the correct location.	DAGR External Antenna Jack The DAGR External antenna connector is the very common SMA (3mm).  Notice the nut on the external antenna cable will be recessed into the pocket so you can not tighten it with your fingers.  There is a "Spinner" available for this.  It's a plastic wheel with fingers that snap onto the hex nut.
PLGR II Rechargeable battery Holder p/n 988-3123-003  made in 2002 holds 6 each AA size rechargeable batteries (the stock battery holder carries 8 AA cells). There is also an external power connector that will NOT accept the standard PLGR power plug.
External Power Connector on PLGR II 6 cell battery holder The connector appears to have the correct threads for the stock PLGR power plug, BUT the plastic case is too small to clear the threaded nut on the plug. A laptop power plug will not work again because the plastic is too close to the socket centerline. It appears to be a design defect.  If you know of a power plug that works let me know about it.

Menus

Setup Menu

INIT   POS/PRECISE    CLEAR

KOI-18 Paper Tape Load

Data Menu

Help Menu

Waypoint Route Menu

Receiver Hardware Status

Data Transfer

Operations Menu

Calculate Menu

Applications Menu

Targeting Menu

Space Vehicle Menu

Tailored Screen Sequence Page

Batteries

Main battery pack plus memory hold -up.

In TM 11-5820-1172-13, pdf page 520, Table 22-1 Common Battery Types:
Table 22-1. Common Battery Types

  * The approximate battery life values are based on continuous mode of operation and operating at room temperature. Battery life will vary depending on temperature and what mode of operation the DAGR is using. Colder temperatures may decrease battery life. Operating modes other than continuous may increase battery life.

** These storage temperatures are for the individual batteries only. The DAGR, stored with primary and/or memory batteries installed, is limited to the operating temperature range in Paragraph 15.2.2, unless further restricted by these storage temperatures

Four AA Main Batteries

All the printing is inside the battery compartment. Notice that the title: Receiver, Hand Held SPS The "SPS" means Standard Positioning Service" i.e. the legal to own civilian model. SPS also appears on the lower right of the front panel. When installing the AA batteries it's best to lower them into the battery holder while holding level.  If you tip the battery and try to install it one end then the other it's a very tight fit. Don't forget to put the removing strap unter the cells. Energizer L-91 Lithium 1.5 V Primary NSN: 6135-01-333-6101 - these have more capacity and work at temperatures where Alkaline batteries fail.  the L-91 also has a shelf life of 20 years.

Memory Backup Battery

2022 Feb: warning about low memory battery.  Installed new one.  Be careful when ordering the battery since some of them come with leads welded on each end. It takes some filing to remove the nub.

The White dot on the memory battery cover and the white dot on the main battery cover are the vents.  Single bump connector is J1, two bump connector is J2. Memory battery is 1/2 AA size 3.6 Volt Lithium.  Radio Shack 23-026 aka: 3B26TC, 3B33TC, 3B955TC, 29045, ER3S, G3 ER3STC, LS3, LS14250 NSN: 6135-01-435-4921 TO4, TL-5101, TL-5101/S, TL5111/S, TL5112, TL5112/S, TL5151 Note there is also a 3.0 Volt Lithium 1/2 AA size battery, but it probably will not last as long. There is no pull strap for this battery and it's a very tight fit, so a small screwdriver may be needed to get it out.

J4 External DC Power

Polaris (DAGR) GPS receiver with Turck PKG3M6S90S Cable

This is the connector the Rockwell documents recommend as of 2008 BUT, it is very difficult to install and remove because the stock nut is almost completely surrounded by the recessed pocket so you need strong fingernails to install it. External Power Consumption vs. Input Voltage 12 Volts seems to be the lowest power drain, hence the voltage on the AC supply. Volts ma mw <7.x 0 0 8 129 1032 10 99 990 15 65 975 20 52 1040 25 44 1100 The DAGR/Polaris switching power supply draws about the same power independent of fluctuations of the input voltage.

Polaris (DAGR) with DAGR specific Cable

This cable was made for the DAGR, but may be very expensive.  The problem is there are really two nuts, the one shown above is on the cable and another nut is installed over it.  The outer nut is not tight against the internal nut so after it's been snugged when you wiggle the outer nut you feel slop.  That may be because someone who has not been properly trained over tightened it and that may lead to a broken plastic case.   The other problem is that the nut makes a rattling noise when the receiver is shaken.  That might consume a lot of someone's time trying to find where the rattle was located.  Note the outer nut is in reality a finger driven socket wrench. Plastic finger driven socket wrenches are used on more modern cables. J4-1 = Ground = Brown J4-3 = Positive = Blue J4-4 = no connection (or ?)

	DAGR External Power Cable Fused (5m) 987-5019-001 NSN: 6150-01-521-6757	Use to connect a DAGR to an external power source DAGR connection can be secured to prevent inadvertent removal Lugs installed on source end of cable 3-pin power plug (F) In-line fuse holder installed 5 meters
	DAGR External Power Cable, Fused (2 m) 987-5009-001 NSN: 6150-01-521-6755	The DAGR-to-external power cable, fused provides for connection between a DAGR and an external power source 3-pin power plug (F) 2 meters
	DAGR Cigarette Lighter Power Cable 987-5008-001 NSN: 6150-01-521-2548	The cigarette lighter power adapter provides for connection between a DAGR and a cigarette lighter DAGR connection can be secured to prevent inadvertent removal 3-pin power plug (F) In-line fuse protected Coiled cord
	DAGR AC Power Adapter 987-4975-001 NSN: 6130-01-521-3157	Connects the DAGR to an AC power source Compatible voltage: 110 to 240 volts Two prong, North American style plug 3-pin power plug (F) Operates on 50 or 60 Hz 3 meter cord Input: 100 - 240 VAC Output: 12VDC  1.0A
	Cold Weather Battery Pack 987-7050-001 NSN: 6130-01-530-4652	Cold Weather Battery Pack (CWBP) is an external power supply designed for extended use with a DAGR when batteries are the only practical means for power 8-AA cells (consisting of two 987- 6641-001), 1.5 VDC 3-pin power plug (F) on pendant cable 1 amp fuse CWBP requires two spare prime power battery magazines (987-6641-001) that are sold separately Designed to be used with Molle M16A2 Magazine Pouch or NSN 8465-01-465-2092 Molle II Mag Pouch The cable is in my opinion too short and the external power connector would benefit from a right angle.  Normally cold weather battery systems have a long cord so that the battery pack can be placed inside clothes to keep it warm. (RPG-7 sight).  You need the separate Cold Weather Battery Pack Cable to use this adapter, see below. Note this adapter takes two battery holders and they are wired in series so it supplies 12 Volts to the DAGR.  If the same batteries were used for all three battery holders the run time would be tripled.  But I don't see a use for that.   It's very awkward to stack the adapter next to the DAGR.
	Cold Weather Battery Pack Cable 426-0227-010 NSN: 5995-01-533-3421	Cold Weather Battery Pack (CWBP) cable is an external power cable that interfaces the CWBP to the DAGR 3-pin power plug (F): P1 3-pin power plug (M): P2 2 meters
	Molle II Pouch,Magazine, M16A2, Double (30 Rounds) NSN 8465-01-465-2092 DAAK60-97-D-9302	Mag Pouch used to hold the Cold Weather Battery Pack (CWBP)
	Spare Prime Power Battery Magazine 987-6641-001 NSN: 6135-01-521-3064	Spare prime power battery magazine is interchangeable with the prime power magazine that is provided with the DAGR 4-AA cells, 1.5 VDC note: Using Energizer L91 Lithium primary battery since it has many advantages. ------------------------ These are probably on the market because the rubber gasket is old and cracking. This makes it difficult to install or remove the battery magazine. The same thing happens to the gasket in the U-229 audio connector. Replacement O-Ring is 3/32" x 3" -149 size - a dab of Silicon grease will prevent this.  Also getting a material, like Viton (Wiki), that does not biodegrade is a good idea. (rubber biodegrades in air or water.)
	Adapter Cable PLGR External Power 987-5020-001 NSN: 6150-01-521-3510	The cable adapter PLGR external power provides for connection between a DAGR and a PLGR external power cable Right angle plug (M) - ? 3-pin DAGR power plug (F) 8 inches

J1 & J2 D-Sub 15 Pin Connectors

J1 Functions

J2 Functions

TBD port Functions

COM Port Protocols

Each COM port can be setup to support:
Inputs: ICD-153, Local Area DGPS, NMEA
Outputs: ICD-153, NMEA

This screen is the same on the Polaris and DAGR.

Have Quick & 1 PPS J2 Cable

	The 1 PPS output from the Polaris Guide feeds the trigger input on the SRS DG535.  The DG535 can be set to create any desired delay, such as 268.8 ms to start of 10s of seconds.  The DG535 output triggers the scope Chan 1.  Have Quick data is on Scope Channel 4. It's a challenge to get all the software needed for the USB video camera to work.  Under the scope and above the plywood shelf is the Ultralink WWVB receiver.  That data waveform on the scope has been offset so it's at the very bottom so that the video camera can see the data and the time.
	Have Quick Cable p/n 987-5002-001 NSN: 5995-01-5212-680 This cable only works on J2. DAGR plug marked P2 and has two raised dots. PIN Function 1 nc 2 nc 3 black Ground 4 nc 5 nc 6 nc 7 brown Have Quick 8 nc 9 nc 10 nc 11 nc 12 nc 13 nc 14 nc 15 nc
DAGR to PC Cable	p/n: 987-5012-001   NSN: 5995-01-521- 3198 This cable only works on J2 COM1. DAGR plug marked P2 and two raised dots. Three wire interface. No RTS/CTS like on COM3. No connections for COM2 RS-422. DAGR  Pin DAGR Func PC Pin PC Func 1 nc 2 1PPS-In_Rtn 5 Gnd 3 nc 4 nc 5 nc 6 nc 7 nc 8 nc 9 nc 10 nc 11 nc 12 nc 13 nc 14 COM1 Tx 2 RXD 15 COM1 Rx 3 TXD 1PPS-In_Rtn is the same as COM1_RTN There is no jumper on the computer DB-9 between 7 and 8 so the computer must have it's serial port set for no hardware handshake. The PLGR to PC Cable is functionally the same. p/n: 426-0141-010   NSN: 6150-01-375-8664
	The P2 Cable has a dog leg or double bend to reduce the distance it sticks out the back to a minimum.  The connector is marked both with two dots and with "P2".  This might be a PC or Have Quick cable. What are the two brass threaded inserts used for?  Let me know.
DAGR/PLGR to DAGR/PLGR Cable ------------------------	NSN: 6150-01-375-8663 p/n 426-0141-020 This is a 42" long cable to allow connecting two GPS receivers together either DAGRs, PLGRs or a mix. The cable is symmetrical and does not have markings for port 1 or port (the PLGR only had one port) and this cable was made for PLGRs but is also used on the DAGR. Pin Port 1 Port 2 Pin Port 1 Port 2 1 1 PPS In 1 PPS In 6 1 PPS Out 1 PPS Out 2 - 1 PPS Rtn 11 - PPS_O_Rtn 3 - - nc - - 4 - - nc - - 5 - - nc - - 6 1 PPS Out 1 PPS Out 1 1 PPS In 1 PPS In 7 - - nc - - 8 - - nc - - 9 - - nc - - 10 - - nc - - 11 - PPS_O_Rtn 2 - 1 PPS Rtn 12 - - nc - - 13 - - nc - - 14 COM 3 Tx COM 1 Tx 15 COM 3 Rx COM 1 Rx 15 COM 3 Rx COM 1 Rx 14 COM 3 Tx COM 1 Tx This cable can be used to: 1. Load data from a DAGR/PLGR to a DAGR/PLGR that has just been started.  That way you save not only the 15 minutes to load the ephemeris but also can move date & time was well as settings and Way Points, *Etc. 2. Synchronize the Date & Time for the Dual Receiver Gun Laying (Azimuth Determination) app. 3. When reprogramming the firmware. -------------------- A similar cable is marked: NSN: 5995-01-521-2713 CAGE: 13499 P/N: 987-5011-001 The key difference is the orientation of the cable relative to the connector. The older cable (above) has the cable going to the side while the newer cable has the cable going up.
Mystery Cable DAGR Fill Cable p/n: 987-5180-001 NSN: 5995-01-521-3185 DAGR Fill cable.  Thanks to Peter C. for letting me know.	DB-15m Pin Function U-228 Pin
DAGR to SINCGARS (COM 1) Cable p/n: 987-5104-001 NSN: 5995-01-521-3187	The DAGR-to-SINCGARS cable provides for connection between the DAGR and a SINCGARS radio Provides for SINCGARS time fill data input to a SINCGARS compatible device 15-pin D-sub plug (F 6-pin audio jack 3 meters

Shipping Container

Polaris Applications

2022 Feb - both the Polaris Guide and DAGR jump to Jammer finder when the Applications menu is selected.
This is caused by being in the default Basic Function Set which was the case since the receivers had not been used for a long time and needed new batteries.

In order to get access to all the Applications you need to change the Function Set to Advanced:
Menu \ Menu \ System \ Select Function Set \ Advanced.

Azimuth Determination, North Finding, Survey Mode (mil speak: Gun Laying System)

Once in the AZ Determination page proceed as follows:
4AK = 4 Arrow Keys

• Press Menu and scroll to Create New, press Enter
• With the name highlighted, press Enter and 4AK select the letters and numbers for you chosen name then 4AK to move to SAVE and press enter.
• With the Walk Time highlighted press Enter, 4AK to set between 1 and 180 seconds, then press Enter
• The display will ask you to press Enter to start the process.  (Prior to this the receiver should have been in Continuous mode and locked on a number of satellites, but if not then you will need to wait here).  You can't start until at least 4 satellites are being tracked, more is much better because while you are walking you may loose some and if the total number goes below 4 then you need to start over.
• After you are stratified with the number of starting satellites press Enter and the display will switch to the walk time count.
• Walk to the second point and when in position press Enter while holding the receiver still, it will take maybe 5 to 10 seconds to determine position 2. (takes about the walk time again)
  
• When it's done press the down arrow to proceed.
• The data defaults to military units.  Changing the units in the main Menu does not effect this page, so 4AK highlight each field press Enter, and select which units to change, for example the bearing change to degrees and the reference change to True, distance in Miles and feet, etc.
  The first result window shows:
• Single Receiver Method (I think you need to connect a second receiver in order for this to change, it's not a menu choice)
  
• Azimuth: 62.29 deg True
• Back Azimuth: 242.29 deg True
• Range 47.02 Feet (0.01 feet is approximately 1/8 Inch!)
• Estimated Azimuth Error: +/- 000.49 deg.
• Press the down arrow to move to Point 1 Information
  
• 10 S     405008 East
  
•              37905 North
• 988 Ft MSL
• Press the down arrow to move to Point 2 Information
• 10 S   485021 East
•          443379 North
• 987 Ft MSL

Questions:
Is it better to carry the receiver so the LCD is vertical or should the LCD be level? LCD level both for compass and GPS reception.
Where inside the receiver is the internal antenna located? just above the LCD.

Thoughts
Using a choke ring antenna would prevent multipath and so you would not loose as many satellites.  Once a satellite looses lock it is removed from the solution because after it relocks the cycle count is no longer valid.
17 Apr 2009

Zero Baseline Testing Single Receiver Method

A way to test the accuracy of the azimuth determination system is to NOT move the antenna.  In this case the roof top GPS antenna was used for both the first and second positions.  If the Azimuth Determination procedure is run using a fixed antenna the result should be a distance of zero with an arbitrary angle.  Things that can be varied are the receiver mask angle.  Zero degrees increases the number of SVs but also allows for more multipath errors.  It’s also location dependant.  The walk time is controlled by making the setting greater than the actual time and then pressing ENTER at the desired test time.  Note there is no display in the results that will tell you the actual walk time so there’s a few seconds of error in the estimate of the actual walk time.  The number of SVs can be controlled to a small extent by when the test is run since the satellite configuration changes with a 12 hour cycle.

The Walk Time input for the single receiver method just sets the maximum allowed walk time, so it's best to just use two up arrow presses to set it to 180 seconds.  The actual second measurement is made when  you press ENTER at the second location.  My guess is that when the ENTER is pressed the first time the DAGR starts logging carrier phase data.  When ENTER is pressed the second time the DAGR does the calculations involving processing the logged data.  So the time it takes to process the data depends on the actual walk time and is very close to half that time.  For example if the walk time was 2 minutes it will take 1 minute to process the data.

Plot of Range error in Inches vs. Walk time in Seconds

What's not shown is the number of SVs used for the solution.  When the test is started there may be 8 to 10 SVs being tracked, but once any of them drop out they can not be used in the solution so it's not uncommon to loose one or two sattelites by the time the test has finished.   Maybe because of the change in number of SVs and/or different DOPs the test results are not easy to nail down, but you can see there's a definate relationship  between walk time and accuracy.  A very rough rule of thumb might be:
Accuracy (Inches) = Walk Time (Seconds) / 20
For example at 20 seconds the accuracy varies from 1/2 Inch to 2 Inches.
At 60 seconds it varies from slightly more than 2 Inches to slightly more than 5 Inches.
The accuracy seems to get better than the rule of thumb when the walk time exceeds 2 minutes.  I'm not sure of this is real, or not?
The problem with trying to use walk times near 180 seconds is that the DAGR aborts the measurement at 180 seconds instead of making a measurement.  It's impossible to have a walk time of more than about 175 seconds because the pressing of ENTER has some time delay before it stops the test.

So for the single receiver method the possible angle accuracy depends on how quickly you can move the DAGR while not blocking any SVs.  These are just calculations that have not yet been tested.

If normal walking speed is three miles per hour (4 feet per second), then after 180 seconds the baseline would be a little under 800 feet (241 meters).  An error of 9 inches in 792 feet is 0.054 deg (3.26 arc min) or 0.96 Mils.
 
If a running person traveled at 8 miles per hour (12 feet per second) then at 180 seconds the angle would be 9/25344 or 0.0198 deg or 0.35 Mils.
 
If a car averaging 30 miles per hour moved the receiver and the test lasted 2 minutes the expected accuracy might be 0.0054 deg or 0.096 Mils.

Survey Equipment to support Single Receiver Azimuth Determination

SECO makes a number of poles used to support either GPS antennas or prisim retro reflectors that are suitable for this application and have some very handy features.  Since minimuzing the walk time is important a system where the antenna is just plugged in rather than locted is important.  Although SECO makes a number of clamps to hold survey data collectors they don't have anything that's DAGR specific so I'm going to try and modify one of their plain pole clamps to allow the stock DAGR mounting bracket to be attached.  (13 April 2009)

Part of Azimuth Determination Setup

SECO Pole (see: Tripods: Range Poles)

The Pole and bipod are standard SECO (Survey Equipment Co) items.  This is a very modular system where all the pole sections have 5/8-11 female threads on both ends.

A friction clamp is holding the DAGR standard mount with a 10-32 screw and flat washer making the connection.  The left mounting hole in the DAGR mount is used so that the back connector area is clear of the pole.

Just below the DAGR there is a circular bubble level (black object to left of pole).

Just below the bubble level is a quick disconnect fitting.  The black pole is attached to the pole above and can be lifted off the lower pole.

The lower pole is fitted with the bipod.  The upper part of both bipod legs has a lever actuated length adjustment to allow easy plumbing of the pole.

Rather than spend a lot to get another of these pole setups, I just got a male quick connect pin with a 5/8-11 female thread to put on top of my existing surveying tripod for the second location.

The pole plus bipod arrangement has an advantage over a tripod in that the distance between the GPS antenna and the mark on the ground is a fixed distance.  That's not the case with a tripod.

This setup breaks down to a much shorter length and fits into a carry bag.

DOP Planning

Yesterday (17 Apr 09) there were 7 satellites being tracked but after moving the receiver 33 paces away and returning to the pole the error message was poor satellite geometry.  So some planning needs to be done before hand to chose a time when the geometry is good.  Trimble has a free program called "Planning" to do this. 
Trimble Planning Software Downloads -
They also have a web page where you can get current GPS data.
GPS Data Resources - Almanac files

Outdoor Zero Base Line Walk

21 Apr 2009 - Choose 11:45 to 12:05 window and tried two walks. 
The first for about 2 minutes resulted in a no solution, poor DOP message.

I'm guessing that if I walk too close to my house some sats are blocked and dropped and the remaining sats don't have a good enough DOP.  So to access some locations the path may need to be curved to keep clear of the house GPS shadow.

The second for about 1 minute resulted in a distance error of about 4 inches.

28 Apr 2009- It's straight forward to modify the  987-5006-001 mount by adding SECO p/n: 103868-005 (5198-052 or 5198-056) and the associated 1/8 x 7/16 spring pin and 1/4-20x1/2 cap screw.  Then it plugs into the p/n 5198-052 Pole Clamp and can be adjusted for tilt.  You can just see the spring pin below the quick release pin on the mount that mates with one of the the small holes on the pole clamp.  While the clamp was designed for a range pole, it works fine on a shelf.

Averaging

Procedure

When displaying the current position press:
MENU - scroll to Select Op Mode - press ENTER - scroll to Average - press ENTER - when a screen to Do NOT MOVE press ENTER again.  Note just below the longitude display the seconds count will increment once per second until it gets to 32400 (1/2 a day or very close to one orbit of the GPS constellation, the optimum time for an average).

Results

In good weather the difference between repeated averages that are 32400 seconds long is 0.01 arc seconds on lat or long and 1 foot in elevation.

April 2015 DAGR with antenna on windowsill (poor view of sky):

Date	Lat (N)	Lon (W)	Elev (ft)
7 Apr 2015	39:11:24.30	123:09:50.57	na
7 Apr 2015	39:11:24:.32	123:09:50.57	924
8 Apr 2015	39:11:24.28	123:09:50.57	927
8 Apr 2015	39:11:24.31	123:09:50.52	927
9 Apr 2015	39:11:24.29	123:09:50.55	931
10 Apr 2015	39:11:24.29	123:09:50.54	933
11 Apr 2015	39:11:24.28	123:09:50.54	934
11 Apr 2015	39:11:24.33	123:09:50.49	916
12 Apr 2015	39:11:24.28	123:09:50.54	926
13 Apr 2015	39:11:24.29	123:09:50.53	926
13 Apr 2015	39:11:24.30	123:09:50.52	930

Compass

This is a 2D compass and so has major errors if the LCD face is not perfectly level.  There should have been a small bubble level built into the receiver.  You can set the compass to display bearings referenced to either the magnetic North pole or True Bearings based on the corrections in the World Magnetic Model (Wiki, Sensors)

DAGR Polaris Guide GPS Receiver Compass Sights There is a raised North arrow just above the center of the display. The down arrow is a raised button with a bearing fudicial line on the bottom that acts as the rear sight. In the upper right of the display is the compass bearing ddd.d. I find even with the receiver on a table it's difficult to set it to better than a few tenths of a degree.  The display in the photo shows 000.2 deg NOTE:  The receiver needs to be held so that the plane of the LCD is horizontal.  Any tip left, right, front or back will introduce an error in the compass reading.  Best to use the compass with the receiver resting on a non ferrous table or in the mount (with the mount horizontal). I'm guessing this type of a calibration corrects for hard iron (nearby magnets) as well as soft iron (metal that distorts the Earth's magnetic field.)  That means that the calibration should be done as close to how the magnetic compass will be used.  So, for example, you should not calibrate on a wood table if you plan to use the compass while carrying a rifle or other iron material.  If it will be mounted in a vehicle that vehicle should be driven in a circle to do the calibration.

The DAGR/Polaris Guide has in built-in magnetic compass.  In addition there's a built in World Magnetic Model which needs as inputs the current date, Lon, Lat and Elevation.  Since this is a GPS receiver that knows all those inputs the local magnetic deviation is known and so you can choose to have the compass display referenced to: Magnetic North, True North or Grid.

Calibrate

It seems that you need to calibrate the compass just prior to using it.  This needs to be done away from metal objects.
MENU, MENU, Display Setup, ENTER, scroll to INTERNAL COMPASS, ENTER, ENTER (highlights a field) scroll to ActiveDisabled and use arrow keys to select ACTIVE, ENTER. Scroll down to Last Calibrated, ENTER, scroll to Select Time Zone, ENTER, scroll to your time zone, ENTER.
ENTER, scroll to CALIBRATE while holding receiver level press ENTER and start rotating so the bearing rotates in a full circle.  Watch the display to see if you get a good cal.

Use

The Compass is in the Navigation Displays menu on the Position page with one press of the scroll down arrow.
Once on the Present Position page press ENTER, then use the arrow keys to highlight the compass display and select the bearing reference (I like True which is something other compass designs can not do).
The receiver needs to be kept level while using the compass, like on a table or surveying post.

Power Consumption

In the DISPLAY SETUP compass menu there's an option for Enable or Disable the compass.  The manual says the receiver draws more power when the compass is on than when it's off.  With external power I'm seeing a 2 ma current savings when the compass is turned off (2 ma * 13 V is 26 mw)

Time Display

The DAGR / Polaris Guide POSition page, when scrolled down, shows the current time and date.  But, the displayed time is often in error by 1 second.  This is in my opinion a bug in the Rockwell Collins firmware.  All my other receivers that display time have the seconds change at the UTC second boundry.  The Trimble Scoutmaster even displays the tenths of a second correctly, see image below.
The Polaris Guide (DAGR) is showing the time as 0852:00 but the time is really 0852:01.0 as shown on the Trimble Scoutmaster to the right.

An interisting thing about the Scoutmaster display is that the date is shown as:

WED 06 Sep89

That's off by 1024 weeks, i.e. the GPS week rollover problem.
I wonder what the DAGR/Polaris Guide will show in 20+ years?

Internal Magnetic Compass

The Internal Magnetic Compass does not have tilt compensation.  The compass can be found at <press and hold POS> then <down arrow> to see the compass (you may need to press Enter and arrow keys to highlight the compass, the Enter and activate it since the normal mode is not continous operation).  I found that the first calibration was no longer working by turning in a circle and noting that the display did NOT show the expected 0 to 359.9 deg range but instead showed numbers around 160 degrees plus or minus maybe 30 degrees.  After a simple calibration it was working fine.

To check for tilt:
Face magnetic North (or magnetic South) and tilt up or down about 10 degrees and note the change in reported bearing is only a few degrees.
While holding the receiver level, Face magnetic East (or magnetic West) then tilt up or down about 10 degrees.  This causes about a 10 degree error in the bearing because there is no internal tilt compensation.

The Suunto Vector wrist instrument has a bubble level (just above the 7 in 337) on it's face to aid in holding it level.
The small rectangle in the upper left is the barometric pressure history.
"N" for North which is the closest of the three letter compass points.
337 degrees magnetic bearing.
The black bar below the bearing has a band at the right end below COMP for compass mode.
The modes are left to right: Time, Alti, Baro, Comp
3:57 local time.
On the very outer circumference at the top is a single black tick.  Opposite it are three ticks.  These form a North pointing arrow.
The Bezel was set to the local magnetic devation years ago and you will see that the North Arrow is pointing very close to the "N" on the bezel.   So the line from 6:00 to 12:00 is pointing close to True North.

See: Experiment Relating to the Vertical Component of the Earth's Field for a similar experiment to that above for the Polaris/DAGR.

Operating Modes

Cold Start

Maps & Images

SV Messages

Internal

External

Trimble 28367-40	Seems to work OK.  It has an SMA connector mag mount. L1 Volts mA 1 5 2 10 3 14 3.188 15 4 17 5 20
Trimble 17572-100 16240-00	This is a survey grade antenna with  5/8-11 threads. A couple of tie-wraps holding the DAGR mounting bracket to the threaded rod. L1 or L1/L2? Works well at about 37 mA. Volts mA 1 9 2 20 3 37 3.047 37 4 98 5 150
AeroAntenna Technology AT575-75AW-TNCF-000-RG-36-NM	This is a survey grade antenna with North Arrow and 5/8-11 threads. The threaded rod is rrequired since the TNC connector on the antenna would otherwise hit the black tripod adpter. L1 AT575-75 Frequency: 1575 +/- 5MHz(L1)+ Glonass Polarization: Right Hand Circular Axial Ratio: 3 db max Gain: 00,12dB,26dB,36dB Voltage: 00,05,RG(5-18VDC) Impedence: 50 OHMs Connector: TNCF,BNCF,NTPF VSWR: <=2.0:1 Magnet: NM(No) Finish: Weatherable Polymer Color: W,O Weight:13 oz max. Volts mA 1 1 2 11 3 17 3.167 18 4 23 5 36
AeroAntenna Technology AT2775-42 with the Choke Ring	Now being used with Ashtech Z12R GPS receiver, but probably will work with DAGR.  It should be the best antenna so far for North Finding because of the choke ring lowering multipath fading.
Sensor Systems S67-1575-58	This is a passive antenna, i.e. no gain and is a DC short circuit.  The Polaris Guide protests: L1 WARNING! EXTERNAL ANTENNA FAULT DETECTED This is caused by the DC shorted nature of the antenna.  You can see in the photo at left that the Polaris Guide (DAGR) is working fine with a passive antenna.  All that's needed is a series resistor choonen to present the minimum acceptable power consumption to make the receiver happy and allow the passive antenna to be used.
Garmin GPSIII Plus Antenna	This is a DC open antenna so the receiver does not know it has an external antenna attached.  Tried to fool the receiver by pointing it up and covering the top with my hand while not coverning the external antenna, but this caussed a jamming warning message.  A DC load would needs to be added to try it.
KS24019L112C	Lucent Quad-Helix GPS Antenna KS24019L112C 5" tall x 3 1/8" dia. Type-N male connector 4 helicoil inserts in ____" square pattern. 26 dB gain at ______ to _____ DCV.
	The RF amp is below the ground plane plate. With a Fluke 87V DMM in diode mode the antenna Vf (1 ma) reads 1.65 V.
RA-1 Magnetic Mount Remote Antenna p/n: 13499-013-1981-010, NSN: 5985-01-502-6692 Commercial model:  AT2775-1030-SMAF-000-03-26-IM 4: magnets (random polarity) 3: 6-32 tapped holes 1: 10-32 tapped hole 0: 1/4-20 tripod holes A 10-32 x 1/4" socket head cap screw uses a 5/32" hex bit.  In a pinch a 4mm might work.  A 4mm ball head works. DC Checks: Fluke 87V DMM - Red Center Black Center Diode 0.897 V 0.567 V Ohms 0.648 M 346.7 k DAGR antenna cables for the RA-1 are:	When the voltage gets to 2.6 V or higher the current limits to 35 ma.  Only tested up to 5 V but may work with higher inputs???? Let me know if you know the upper limit. Volts mA 1 3 2 24 3 35 3.167 35 4 35 5 35
DAGR to RA-1 Cable (5m with SMA connector), p/n: 13499-987-4640-001, NSN: 5995-01-504-1762 DAGR J3 Antenna SMAf DAGR with RA-1 and 5m cable	p/n: 988-9389-001 NSN 5935-01-534-6963 WANTED: Name of manufacturer who makes this SMA thumb whee "Spinner".  Let me know. It may be DCX-CHOL, have RFQ in the works 22Aug22
DAGR to RA-1 Cable (10m with SMA connector), p/n: 13499-987-5016-001, NSN: 5995-01-521-4244
DAGR to Helmet Antenna Cable, p/n: 13499-987-7002-001, NSN: 5995-01-521-6753
SMA DAGR Spinner p/n: 13499-988-9389-001, NSN: 5935-01-534-6963 Name of manufacturer who makes this SMA thumb whee "Spinner".  Let me know.
Commercial SMA Wrenches that fit into DAGR Antenna connector hole.  But these are tools that will be something seperated from the DAGR and can easily get lost.  The plastic thumb wheel is compact and attached to the DAGR. KCR Products - Combined with torque wrench, patent US7080581 -or- Mini-Circuits: without torque wrench (but about same cost) HT-2-SMA

Breakout Box

Marked: 80063-A3157778
The three terminal pairs are marked:
Ch1 Xmt/Rcv A & B (yellow wire on A, black wire on B)
Ch1 Rcv A & B
Ch2 Xmt/Rcv A & B

This fits either J1 or J2 on the DAGR or the Computer Interface 15-pin connector on a PLGR.

Fig 1

Fig 2

Pinout

DC Power