W0RPK GPSv60KFT

GPS RECEIVERS = vs=20 60KFT
Ralph Wallio, W=D8RPK W0RPK at=20 netINS.net
Updated=20 07Jun09

The=20 60kft limit (aka 18km) is one of the three vehicle dynamics limitations = placed=20 on GPS receivers for we civilian unwashed, = altitude,=20 vehicle velocity and acceleration. GPS receiver=20 manufacturers are allowed some leeway to juggle the values of these = limits to=20 serve their markets so details vary between manufacturers, between = models from=20 the same manufacturer and even between software versions in the same=20 model. The 60kft (18km) upper limit of controlled airspace is the = altitude=20 limit most often used.

Amateur high altitude balloonists have = discovered=20 a few GPS receivers that allow operation above 60kft = and often=20 announce their findings to our small community. I have yet to hear = of=20 balloonists using expensive GPS=20 simulators for this test so this knowledge results from actually flying=20 receivers above 60kft and experiencing the results. This web page = is=20 intended to gather first person information submitted by individuals and = groups=20 that have tested receivers.

We will need to be picky about = models,=20 software versions and dates so submitted information will need to=20 include:

Manufacturer
Model number (complete)
Software = version=20 (often output at power-up)
Individual or group involved in = test
Date of=20 test
Test result (Pass or fail)
Other relevant=20 information

RECEIVERS = THAT PASS=20 THE 60KFT TEST

MANUFACTURER

MODEL

SOFTWARE

TESTED = BY

TEST=20 DATE

DATE=20 POSTED

DeLorme

TripMate

(Rockwell ZODIAC=20 chip set and commands)

TBD

ARSAT=20 (N5SNN)

10Sep05

18Mar06

FASTRAX
See Notes [3]=20 [7]

iTrax02

V=20 1.11

AMSAT-France
(F6FAO)

15May04

18May04

GARMIN

ETrex

2.11

KMC
(Pioneer=20 Astro)

17Apr02

13Jun02

GARMIN

GEKO=20 201

V=20 2.0

TVNSP
(KD7OST)

TV03G=20 12Jul03

13Jul03

GARMIN

GPS-16-HVS

2.3.0 = &=20 2.9.0

TVNSP

(N7MTZ &=20 W7MJR)

04Jul04

05Jul04

GARMIN = [Note=20 9]

GPS-18-LVC

2.30 = &=20 2.40

TVNSP
(KC7DBA)

06Nov04

14Nov04

GARMIN = [Note=20 9]

GPS-18X

GPS-18Xvc

3.00

SARA=20 (K=D8BR)

NTI=20 (N5NTI)

04Apr09

22May09

21Apr09

07Jun09

GARMIN

GPS-25=20 LP-LVS

GPS 25-LVS = V2.5

F1SRX

12Jun2003

30Jan04

GARMIN

RINO

TBD

HABITAT = SKYLAB

(KA=D8JLF)

01Aug04

03Aug04

GARMIN

GPS-35HVS

GPS 25-HVS = V2.5

W=D8ZC

22Apr01

05May01

GARMIN

GPS-15H

2.70

KB8PVR

09Apr05

19Apr05

INVENTEK [Note=20 11]

ISMF2-C5.1-V004

C5.1-V004

WB8ELK

17Jan09

20Jan09

MOTOROLA

GT+ = ONCORE=20 [5]

KI5CZ

1998

07Dec04

MOTOROLA

M12
P183T12N12

61-G10002A
Ver.1 Rev. = 3

ANSR
(KD7LMO)

12Jan03

MOTOROLA

M12+
P283T12N15

61-G10002A
Ver.1 = Rev.=20 8

ANSR
(KD7LMO)

07Dec02

12Dec02

NAVMAN

JUPITER = 32

(SiRF=20 III=20 chipset)

GSW3.2.4-SDKNM_3.1.00.12-SDK001P1.00a
Jupiter32=20 v2.1 build 1 (S3)

ANSR

(KD7LMO)

15Dec07

31Dec07

RAND=20 McNALLY

Streetfinder=20 GPS for = the Palm=20 III

(ROCKWELL=20 ZODIAC)

ZODIAC=20 V1.83

ORB

(KC5TRB)

ORB-5=20 14Sep03

18Sep03

ROCKWELL
(CONEXANT)

JUPITER
TU30-D140-221/231
[Note = 6]

JUP=20 V1.80
CRC:CFB5

EOSS
(W5VSI)

EOSS-39 = 12Mar00=20 thru -49 21Apr01

08May01

TRIMBLE

COPERNICUS
(AIR=20 mode)

2.01.1

Meteotek08

28Feb09

21Apr09

TRIMBLE

LASSEN = LP=20 GPS P/N=20 39263-00

7.82

BEAR
(VE6SBS)

BEAR-1=20 27May00
BEAR-2=20 05Aug00

23Jun01

RECEIVERS = THAT FAIL=20 THE 60KFT TEST

MANUFACTURER

MODEL

SOFTWARE

TESTED=20 BY

TEST=20 DATE

DATE=20 POSTED

AXIOM

SandPiper

SiRF = Star-1=20 chipset

[1]

unk

BYONICS

GPS2

SiRF-III

Notes [1 = &=20 8]

LASA

24Nov07

27Nov07

DELUO

(rebranded=20 EVERMORE)

Note=20 [4]

Serial=20 GPS

Unknown

EOSS-83

(K=D8ANI)

08Aug04

09Aug04

DELUO

Lite

Unknown

(Sony=20 chipset)

K5IS

16Apr05

28Apr05

GARMIN

GPS-45

3.05

EOSS
(KC=D8JHQ,=20 N7QAM)

26Sep01

10Jan02

HOLUX

GM-210=20 [1]

(SiRF-II = chip=20 set)

$Version=20 2.3.2-GSW2-2.05.024-C1Prod1.1

$SiRF = version :=20 2.3.2 uservesion : GM210V41

TABEL

KE4PJW/KQ4TV

22Apr06

01Jul06

28Jul06

HOLUX

GR-213

(SiRF-III chip=20 set)

Also=20 failed

Info=20 pending

TABEL

KE4PJW/KQ4TV

01Jul06

28Jul06

RADIO=20 SHACK

DigiTraveler

Note=20 [2]

ROCKWELL
(CONEXANT)

JUPITER
TU30-D140-061
[Note = 6]

JUP=20 V1.03

EOSS
(KC=D8YA)

24Jan06

SAN=20 JOSE
NAVIGATION

FV-17
(FURUNO=20 GN-79N)

Unknown

Alfred = Kastler=20 school
(F5FJA/F6FAO = =96=20 France)

13May04

02Jun04

TELIT

(24km = ~80kft=20 alt limit)

GM862-GPS

(SIRF-III)

Unknown

EDGAR-1

(VA2TCV)

05Apr08

20May08

TRIMBLE

LASSEN=20 SKII

7.74

NSERT=20 (WA8RC)

17Apr09

21Apr09

Note=20 [1] We = now=20 have solid evidence that GPS receivers = based on=20 SiRF-I and SiRF-II chip sets all fail at ~60kft. Some=20 SiRF-III chips sets, = receivers=20 that use them and firmware work at high altitude =96but- others do not. = =20

Note=20 [2]=20 We have a report that a Radio Shack DigiTraveler=20 GPS receiver = max=92ed-out at=20 9,999m but continued with reliable 2D navigation.

Note [3]=20 Warning de = F6FAO:=20 To have the GPS working = above 18 km,=20 you need to send a command to the GPS. This = command is =91Set=20 Upper Limit=92.

Note=20 [4] = The DeLuo=20 Serial GPS receiver is = a=20 discontinued product but DeLuo continues to sell a few EverMore=20 GPS = receivers. It=20 appears all EverMore receivers are limited to 18km altitude. Some = other=20 DeLuo GPS receivers = are based on=20 either the SiRF Star-I or SiRF Star-II chip sets which are limited to = 18km per=20 above.

Note=20 [5] = Motorola=20 GT OnCore receivers in both 6-channel (earlier) and 8-channel (later) = versions=20 were successfully flown above 18km by FreeSpace, and HABET = (ISGC/ISU). =20 Model numbers and software versions are no longer = available.

Note=20 [6] = From Steve=20 KC=D8YA of EOSS: Early Rockwell Jupiter boards, serial numbers = <300,000 with=20 V1.03 software, have failed above 30km. Later boards, serial = numbers=20 >386,000 with V1.80 software, have repeatedly worked ok. = Contact Steve=20 for more details.

Note=20 [7] = Gerard=20 Auvray, F6FAO, forwards the following information from FASTRAX=20 support:

De : Fastrax Customer Support [mailto:support@fastrax.fi]=20
Envoy=E9 : lundi 21 mai 2007 16:33
=C0 : = AUVRAY=20 GERARD; Fastrax Customer Support
Objet : RE: Max altitude = for=20 GPS

Hello=20 Gerard,

The = following=20 receivers can be used above 18 km:

iTrax03

iTrax03-s

iTrax130

uPatch130 (new=20 receiver, available beginning of Q2)

They all = work if=20 speed is < 1000 knots

http://isuite.f= astrax.fi/faq.html#mozTocId469010

Other = receivers=20 limit the height to either 20 km (uPath101,102) or 60000 feet (All Sirf = based=20 receivers like iTrax300, uPatch300) regardless of speed.

The only = receiver=20 actually tested above 18km in a real application (in a weather balloon) = is=20 iTrax03.

Note=20 [8] Byonics=20 GPS2 cut out = when the=20 payload ascended beyond 78,838', and resumed
after burst when it = descended=20 below the same level one hour later. =96 Rick LASA

Note=20 [9] On = 23Aug08=20 a new *GPS18xLVC* froze = altitude=20 at 60kft. Garmin development staff found the software = problem
which is=20 fixed in software V2.80

&= nbsp; =20 K=D8BR reports a successful flight using a Garmin GPS-18X V3.0 to = 87lft on=20 04Apr09.

Following = information=20 from W0JRT:

&n= bsp; =20 There seems to be a lot of confusion about this. Hopefully = this
message=20 will clear things up. The link that was posted
(http://showcase.netins.net/web/wallio/GPSrcvrsvs60kft.htm= )=20 does not
make it entirely clear as it mixes up the "GPS = 18-LVC" and = "GPS
18x-LVC", or at least = lumps them=20 together. Although they look similar
physically they are two = completely=20 different models with completely
different part numbers running = completely=20 different software (although
most likely with a lot of shared=20 source.)

The GPS 18-LVC with the 5 meter cable is/was produced under=20 two
different part numbers: 010-00321-06 (non-RoHS) and=20 010-00321-56
(RoHS). They are functionally identical and run = the same=20 software.
The only difference is that one was built with = RoHS-compliant=20 parts
and RoHS-compliant processes.

The GPS = 18x-LVC with the 5 = meter cable=20 has the part number 010-00321-36.

The latest software = (006-B0273-00) for=20 the GPS=20 18-LVC is=20 v3.20
released in October of 2007.

The latest software = (006-B0796-00)=20 for the GPS=20 18-LVC is v2.70=20 August
of 2008.

If you have a GPS = 18-LVC there is no = problem=20 flying it on a balloon.

If you have a GPS = 18x-LVC it currently = has a limit=20 near 60k feet.
Garmin says this was an oversight and they are = working to fix=20 this
since it should meet the same limits at the GPS = 18-LVC.

-Jerome =

NOTE=20 [10] Thomas Scherrer-Tangen, = OZ2CPU,=20 provides the following:

&= nbsp; =20 I have this information directly from Locosys tech department: = ALL GPS modules from = manufacture Locosys no matter chipset or firmware
or date codes will = do this:=20 If the module goes over high or speed limitation it will not longer to = provide=20 existing position data and velocity.
It can recover when high or = speed is=20 back under limitation.

NOTE=20 [11] Bill Brown,=20 WB8ELK, provides the = following:

You = can=20 officially put the Inventek ISMF2-C5.1-V004 GPS=20 module as "passes" for the "GPS receivers = vs. 60k=20 feet" list. It worked great (never lost GPS=20 lock) during my last flight to 110,000 feet.

The = module=20 itself is very inexpensive but the eval board that Inventek sells = is fairly=20 pricey....they have a reasonably priced USB thumb drive = eval=20 board version but it's for the F1 and does not bring out serial = port=20 B that has the balloon NMEA data on it....therefore, I'm about done = with a=20 PC board design that will allow the balloon community to plug and play = the board=20 without having to worry about surface mount soldering....I'll offer the = board by=20 itself for those with surface mount assembly experience. I'll have that = info=20 posted soon on my website: http://www.wb8elk.com/ or http://www.elktronics.com/ = I should=20 have that done this week.

The = V004=20 version is the custom firmware build that allows the SIRF III chipset to = work up to=20 135,000 feet....Inventek has one of the SIRF software designers on staff = according to info I was told when I called them. Here's the ordering = link for=20 the high altitude balloon version:...look for the listing that says=20 "GPS custom = firmware" and=20 select the C5.1- V004 version that says, "NMEA 4800, ceiling 135000=20 ft"

htt= p://inventeksys.accountsupport.com/store/gps_modules.html

This = is a very=20 economical unit, to the price point of a disposable system....and = they=20 don't mind single quantities.

I flew it = with their=20 equally inexpensive active patch antenna (ACTPAT254-01-IP):

ht= tp://inventeksys.accountsupport.com/store/gps_antennas.html

The active = patch has a=20 short coax with a UHL connector that plugs directly into the top of the=20 GPS receiver = module...you=20 can also run a short PCB trace out from pin 1 to an SMA connector if so=20 desired.

The active = patch=20 antenna likes to have a ground plane underneath it for best=20 results...particularly during the acquisition phase....once it's = acquired the=20 satellites, it takes a lot less signal to maintain tracking. I put a = strip of=20 adhesive metal tape attached to some foam core underneath the patch and = it=20 worked great.

The smaller = patch=20 antennas they offer will also work, but I would recommend the 254 = version (about=20 an inch on a side) since that one seems to be the most = sensitive.

So far, I've = seen=20 little or no desense by nearby 70cm transmissions, = something that=20 only the long discontinued Motorola VP Oncore can do in my = experience. It=20 wasn't affected by the ozonesonde signal on 403.2 MHz at all during this = last=20 flight...the Trimble Copernicus was affected however. I will test it in = an ATV=20 payload soon.

The module = operates on=20 3.3 volts and draws just 25 mA during tracking (add about 10 mA for the = active=20 patch)....a big power budget savings over a GPS18 for = example...(the=20 GPS18 is 5V at = 65 mA).=20 Adding a backup coin cell battery to pin 2 allows you to do incredibly = fast hot=20 starts.

Photos of = the 2m=20 transmitter board with the onboard Inventek GPS module can = be seen=20 here...the same board will work on HF as well with different output = filter=20 values.

http://www.wb8elk.com/oz01170= 9.htm=20

- Bill = WB8ELK

W=D8RPK Home = Page