[ARforum] Extended Flock Of Bird

FORUM ON AUGMENTED AND VIRTUAL REALITY

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Dear AR Forum:

I have a diagram describing the Strength of a Flock Extended Range
Transmitter. As the file is too large for this ListBot list, please email me
if you would like a copy.
 Some important things to remember:

1. The Strength of the magnetic field at the sensor is never more than one
of the earths natural magnetic field.

2. What usually happens in this case is that the ERT will cause slight
jitter in the CRT monitor, and as Francois notes, it is near the computer
monitor. The #1 cause of headaches is looking at the monitor and getting eye
strain looking at the "jitter" induced by the ERT.

3. The best solution therefore is to use a standard range transmitter. It is
much more accurate (0.07") and because it is lower power, it won't cause as
much noise or distortion. The ERT in your case Francois, may be
inappropriate for such short range use. I assume you are using an HMD and
are tracking your head?

Anyone may feel free to contact me regarding this issue. We know of no side
effects from the ERT and with government studies testing power lines, etc,
there is now know link to headaches or health hazards. No need to be
frightened.

Regards,

Gregory S. Erdmann
Technical Sales Account Manager

Ascension Technology Corp.
PO Box 527, Burlington, VT 05468 USA
Tel: (802) 893-6657 Fax: (802) 893-6659
mailto:greg@a .................
http://www.ascension-tech.com/
Big files: ftp://ftp.ascension-tech.com/pub/ascension-tech.com/

Magnetic, optical and inertial motion tracking technologies for computer
graphics applications.

-----Original Message-----
From: Francois Dumas de Rauly
[mailto:francois.dumas-de-rauly@t ..................]
Sent: Monday, April 09, 2001 6:05 AM
To: REALITY, FORUM ON AUGMENTED AND VIRTUAL
Subject: [ARforum] Extended Flock Of Bird

FORUM ON AUGMENTED AND VIRTUAL REALITY

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Hi everyone,

Does anybody know on which frequency band does the emitter work on a
Acsension Extended Range Flock Of Bird ?
My problem is that the first time I used this tracker, I put the emitter
near my head (and my computer) and then, five minute later, I started to
have a headache... Is it something that happened to other users of this
tracker ? If so, let me know, because it frightened me a little bit.

Thanks

______________________________________________________________________
To unsubscribe, write to ARforum-unsubscribe@l ..........

From:	"Greg Erdmann" <gerdmann@a .................>	Received:	Apr 9, 2001
To	"FORUM ON AUGMENTED AND VIRTUAL REALITY" <ARforum@l ..........>
Subject:	RE: [ARforum] Extended Flock Of Bird
FORUM ON AUGMENTED AND VIRTUAL REALITY --------------------------- ListBot Sponsor -------------------------- Build a marketing database and send targeted HTML and text e-mail newsletters to your customers with List Builder. http://www.listbuilder.com ---------------------------------------------------------------------- Dear AR Forum: I have a diagram describing the Strength of a Flock Extended Range Transmitter. As the file is too large for this ListBot list, please email me if you would like a copy. Some important things to remember: 1. The Strength of the magnetic field at the sensor is never more than one of the earths natural magnetic field. 2. What usually happens in this case is that the ERT will cause slight jitter in the CRT monitor, and as Francois notes, it is near the computer monitor. The #1 cause of headaches is looking at the monitor and getting eye strain looking at the "jitter" induced by the ERT. 3. The best solution therefore is to use a standard range transmitter. It is much more accurate (0.07") and because it is lower power, it won't cause as much noise or distortion. The ERT in your case Francois, may be inappropriate for such short range use. I assume you are using an HMD and are tracking your head? Anyone may feel free to contact me regarding this issue. We know of no side effects from the ERT and with government studies testing power lines, etc, there is now know link to headaches or health hazards. No need to be frightened. Regards, Gregory S. Erdmann Technical Sales Account Manager Ascension Technology Corp. PO Box 527, Burlington, VT 05468 USA Tel: (802) 893-6657 Fax: (802) 893-6659 mailto:greg@a ................. http://www.ascension-tech.com/ Big files: ftp://ftp.ascension-tech.com/pub/ascension-tech.com/ Magnetic, optical and inertial motion tracking technologies for computer graphics applications. -----Original Message----- From: Francois Dumas de Rauly [mailto:francois.dumas-de-rauly@t ..................] Sent: Monday, April 09, 2001 6:05 AM To: REALITY, FORUM ON AUGMENTED AND VIRTUAL Subject: [ARforum] Extended Flock Of Bird FORUM ON AUGMENTED AND VIRTUAL REALITY --------------------------- ListBot Sponsor -------------------------- Start Your Own FREE Email List at http://www.listbot.com/links/joinlb ---------------------------------------------------------------------- Hi everyone, Does anybody know on which frequency band does the emitter work on a Acsension Extended Range Flock Of Bird ? My problem is that the first time I used this tracker, I put the emitter near my head (and my computer) and then, five minute later, I started to have a headache... Is it something that happened to other users of this tracker ? If so, let me know, because it frightened me a little bit. Thanks ______________________________________________________________________ To unsubscribe, write to ARforum-unsubscribe@l .......... ______________________________________________________________________ To unsubscribe, write to ARforum-unsubscribe@l ..........

From:	Francois Dumas de Rauly <francois.dumas-de-rauly@t ..................>	Received:	Apr 9, 2001
To	"REALITY, FORUM ON AUGMENTED AND VIRTUAL" <ARforum@l ..........>
Subject:	[ARforum] Extended Flock Of Bird
This is a multi-part message in MIME format. --------------020203090605090108010801 Content-Type: Content-Transfer-Encoding: 8bit FORUM ON AUGMENTED AND VIRTUAL REALITY --------------------------- ListBot Sponsor -------------------------- Start Your Own FREE Email List at http://www.listbot.com/links/joinlb ---------------------------------------------------------------------- Hi everyone, Does anybody know on which frequency band does the emitter work on a Acsension Extended Range Flock Of Bird ? My problem is that the first time I used this tracker, I put the emitter near my head (and my computer) and then, five minute later, I started to have a headache... Is it something that happened to other users of this tracker ? If so, let me know, because it frightened me a little bit. Thanks ______________________________________________________________________ To unsubscribe, write to ARforum-unsubscribe@l .......... --------------020203090605090108010801 Content-Type: text/x-vcard; charset=windows-1252; name="francois.vcf" Content-Transfer-Encoding: 8bit Content-Disposition: attachment; filename="francois.vcf" begin:vcard n:Dumas de Rauly;François x-mozilla-html:FALSE org:Thalès Optronique;Algorithmie version:2.1 email;internet:francois.dumas-de-rauly@t .................. adr;quoted-printable:;;Rue Guynemer BP 55=0D=0A;Guyancourt Cedex;;78283;France fn:François Dumas de Rauly end:vcard --------------020203090605090108010801--

From:	Francois Dumas de Rauly <francois.dumas-de-rauly@t ..................>	Received:	Apr 9, 2001
To	"REALITY, FORUM ON AUGMENTED AND VIRTUAL" <ARforum@l ..........>
Subject:	[ARforum] Extended Flock Of Bird
This is a multi-part message in MIME format. --------------020809060905060004060104 Content-Type: Content-Transfer-Encoding: 8bit FORUM ON AUGMENTED AND VIRTUAL REALITY --------------------------- ListBot Sponsor -------------------------- Start Your Own FREE Email List at http://www.listbot.com/links/joinlb ---------------------------------------------------------------------- Hi everyone, Does anybody know on which frequency band does the emitter work on a Acsension Extended Range Flock Of Bird ? My problem is that the first time I used this tracker, I put the emitter near my head (and my computer) and then, five minute later, I started to have a headache... Is it something that happened to other users of this tracker ? If so, let me know, because it frightened me a little bit. Thanks ______________________________________________________________________ To unsubscribe, write to ARforum-unsubscribe@l .......... --------------020809060905060004060104 Content-Type: text/x-vcard; charset=windows-1252; name="francois.vcf" Content-Transfer-Encoding: 8bit Content-Disposition: attachment; filename="francois.vcf" begin:vcard n:Dumas de Rauly;François x-mozilla-html:FALSE org:Thalès Optronique;Algorithmie version:2.1 email;internet:francois.dumas-de-rauly@t .................. adr;quoted-printable:;;Rue Guynemer BP 55=0D=0A;Guyancourt Cedex;;78283;France fn:François Dumas de Rauly end:vcard --------------020809060905060004060104--

From:	PaulinVT@a ......	Received:	Apr 9, 2001
To	ARforum@l ..........
Subject:	Re: [ARforum] Extended Flock Of Bird
FORUM ON AUGMENTED AND VIRTUAL REALITY --------------------------- ListBot Sponsor -------------------------- Start Your Own FREE Email List at http://www.listbot.com/links/joinlb ---------------------------------------------------------------------- Hi Greg, Hope your doing well. I agree swapping out the ERT for a standard range transmitter would work but there is more appropriate solution to the jitter problem on a monitor caused by an ERT. Also, if a standard range transmitter is being used to replace the ERT the location of monitor would still need to be kept outside of the XTMRs range or a jitter condition will occur again. If a larger motion capture range is desired with a FOB using the ERT is to incorporate the CRT Sync function with flock. A CRT Sync cable is needed for this procedure and is usually supplied with a FOB system. The normal configuration of the ERT/ERC is to make the ERC the Master at address 1 but if the CRT Sync function is going to be used with the FOB the ERC would need to be set as a Slave unit at address 2 or higher. A FOB unit would be made the Master at address 1. The CRT Sync procedure in the FOB manual offers helpful information related to the manipulation of the sensor to detect the CRTs frequency. When the Electronic Unit of the FOB system is properly synchronized with the monitors trace frequency the jittery affect caused by the ERT will be eliminated from the monitor. I hope this information was helpful. Respectfully, Paul J. Bugeja Former Technical Support Engineer, Ascension Technology ______________________________________________________________________ To unsubscribe, write to ARforum-unsubscribe@l ..........