[amsat-bb] Instanttrack Altitude?

[Robert Bruninga]

Looking at the latest re-entry plot, why does Instantrack show
an altitude that is 10km below the official prediction?  This is
using an EPOC TLE of 26 November, Instantrack shows 239.5 km
Avaerage altitude.  What do other programs show?

http://www.ew.usna.edu/~bruninga/ande-ops.html

Bob


> -----Original Message-----
> From: aprssig-bounces at lists.tapr.org 
> [mailto:aprssig-bounces at lists.tapr.org] On Behalf Of Robert
Bruninga
> Sent: Tuesday, November 27, 2007 1:09 PM
> To: aprssig at lists.tapr.org
> Subject: [aprssig] ANDE -APRS Re-Entry Campaign
> 
> ANDE-APRS Re-Entry Campaign:
> 
> The ANDE-MAA satellite (Nav Oscar - 61) will de-orbit in the
> next few weeks but is fully operational.  We encourage
activity,
> because while it is in use (2m packet up/down), then it is
awake
> and sending telemetry.  We want to capture the most telemetry
to
> see if we can catch the thermal changes as re-entry
approaches.
> 
> Who can capture the last telemetry frame?
> 
> The most important telemetry is that which is fed live by
IGate
> into the APRS-IS system.  Because that is automatically logged
> and time stamped.
> You can verify your data got in by looking at the
> http://pcsat.aprs.org web page after each pass.
> 
> If you manually capture any packets, Please take special care
to
> accurately LOG the TIME of any packets received especially in
> the final day prior to re-entry.  See the contest page below
for
> how to submit entries:
> 
> Here is the ANDE Operations web page.  It has links to live
> telemetry too:
> http://www.ew.usna.edu/~bruninga/ande-ops.html
> 
> And this one is the CONTEST for data collection and operations
> sponsored by PA3GUO and DK3WN:
> http://www.ande-deorbit.com
> 
> Any APRS station that is also on the internet can contribute
> telemetry by simply QSY'ing their normal APRS rig receiver to
> 145.825 on that final day.
> 
> If you do not normally run APRS or an IGate, then you can
simply
> download ALOGGER.EXE which is a full up IGate designed just
for
> satelite gating without having to learn APRS.  See Bill's web
> page:
> http://www.billdiaz.dynip.com/ASatLogger.htm
> 
> ANDE is coming over the northern latitudes in the afternoons
and
> evenings local sun time, but this pattern moves earlier by 14
> minutes per day.
> Just monitor 145.825 MHz.
> 
> Enjoy!
> Bob, WB4APR
> 
> 
> 
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