Re: SiRF receivers


Ralph Wallio, W0RPK <wallio@...>
 

Michael,

My response is delayed because I have been on the road for several days.
Thank you for this good news. There are very few of us involved in amateur
high altitude ballooning with roughly 10 active programs nationwide at any
given time. Regardless, GPS receiver performance above 60kft is absolutely
necessary.

We do not have access to a GPS simulator so the only method we have to test
for high altitude performance is to fly a mission and find out. Typically
we fly a primary receiver we already understand while we test a secondary
receiver. Primary and secondary receiver NMEA output rides an Amateur Radio
telemetry downlink to ground stations either directly or via payload
processing.

I maintain a web page where we attempt to steer designers toward GPS
receivers we know will work at high altitudes (see
http://users.crosspaths.net/~wallio/gps60kft.html). I would like to add
your information to this list but we first need to fly a test mission.
Unfortunately all SIRF and partner, e.g., AXIOM, specification sheets I have
seen specify maximum altitude as 60,000ft (this includes all SIRF
specification sheets in your web pages).

Manifests for several flights in early July are already locked but we will
prepare for a test flight and advise you of results.

Regards, Ralph Wallio, W0RPK
wallio@crosspaths.net
http://members.crosspaths.net/wallio
Never use software to compensate for a poor hardware system

----- Original Message -----
From: "Michael Castle" <michael.castle@ntlworld.com>
To: <wallio@crosspaths.net>
Sent: Monday, May 27, 2002 17:16 PM
Subject: SiRF receivers


I work for SiRF and can confirm that all SiRFstar 1 and 2 receivers will
work over 60kft. Also SiRF receivers modules are very cheap now, and
have
some excellent low power modes which may be useful for ballooning.
Regards,
Michael Castle

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