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[Fwd: FENGYUN-1C]





-------- Original Message --------
Subject: FENGYUN-1C
Date: Sun, 23 May 1999 12:44:46 +0200
From: Matjaz Vidmar <s53mv@uni-mb.si>
To: pg@tasma.aball.de
CC: s53mv@uni-mb.si

Hello Peter,
maybe the following may be of interest to some AMSAT members?
                                       73s de Matjaz S53MV

S SATELL @WW
Images from FENGYUN1C

Hello!
The new weather satellite FENGYUN1C is transmitting HRPT images
similar to NOAA HRPT. Here are the results of my observations
during this weekend:

Keplerian elements:

FENGYUN 1C
1 25730U 99025A   99137.13598955 -.00000043  00000-0  32760-6 0  2362
2 25730  98.7928 183.3498 0013136 302.0815  57.9080 14.10242932  1009

Transmission frequency:   1700.400MHz (+/- 40kHz Doppler).

Modulation: 1330.8kbps Manchester encoded unsymmetrical BPSK with
residual carrier (same as NOAA HRPT but twice the data rate).

Frame format: 221800 bits organized in 10bit words, 6 frames per second
(twice the length of NOAA HRPT, same sync sequence transmitted at twice
the NOAA HRPT rate, same number of frames per second).

Image data: 1 line = 2048 pixels * 10 spectral channels * 10 bits.

Channels 1, 2, 6, 7, 8, 9 and 10 contain visible/near-IR data.

Channels 3, 4 and 5 produce a white picture (probably thermal-IR
long-wavelength channels awaiting radiometer decontamination).

Channel 2 produces the best ground/sea contrast and it is probably the
standard visible/near-IR channel compatible with NOAA HRPT channel 2.

Image geometry corresponds completely to NOAA HRPT (same number of
pixels, same image width and line rate).

Equipment used: 90cm diameter dish with helix feed for 2.4GHz (still
works at 1.7GHz...) with masthead preamplifier, standard NOAA HRPT
receiver (bandwidth too narrow), standard NOAA HRPT bit synchronizer
(clock xtal exchanged for the doubled data rate), standard
NOAA HRPT aux frame synchronizer (end-of-frame aux sync) and data
demultiplexer modified for the 10 spectral channels (versus the 5 used
by NOAA HRPT).

With the above equipment completely noise-free images were obtained at
elevations above 30 degrees, although useful images can be received
down to about 5 degrees elevation.

                        73s and good image hunting de Matjaz S53MV

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