aes_ice - exports AVHRR Terascan datasets to AES Ice Center format.

aes_ice - Exports AVHRR Terascan datasets to AES Ice Center format.

SYNOPSIS

aes_ice  [ inputfile ]

site_initials is the only optional parameter .

DESCRIPTION

aes_ice converts uncalibrated, unregistered AVHRR datasets to AES Ice Center format. Output data consists of one Ephemeris Data File and several Image Files, with one file per channel. Output file names are automatically generated as nnnnncrrrr, where nnnnn is a 5 digit orbit number, c is either channel number or E for ephemeris, and rrrr is a 4 digit record size in bytes.

The record size is the width of the input imagery, plus 194 bytes. For example, if the input image is 2048 pixels wide, then the resulting record size would be 2048 + 194 = 2242. All records in all files are padded out to the same length.

Image records are (194 + pixels_per_line) bytes long with no padding needed. Ancillary data consists of HRPT minor frame header data with the leading 6 sync words removed. Each of the remaining 97 header words takes up two bytes.

AVHRR image data is converted from short to byte type by dividing by 4. Therefore, it will work only for non-calibrated data. The aes_ice function will abort if the data units are different from raw counts.

Currently, subsampling or channels selection is not supported. Since the input is Terascan dataset, the user can perform these operations before running aes_ice, using available TeraScan functions.

PARAMETERS

site_initials: OPTIONAL. This is a 3-letter value to insert into the output file headers and trailers. The default site initials are WHX, which stands for for Halifax. Site initials are forced to be upper case.

EXAMPLES

The following example shows a 1-channel NOAA-12 dataset being converted to AES Ice Center format. ASCII auxiliary data is echoed to the screen for visual inspection. Note the automatically generated output file names. Also note the site initials WHX in output file headers and trailers.

[1]% avin .
on_pass_disk   : char(  3) ? [yes]
pass_number    : int (  8) ? [6] 7
use_master     : char(  3) ? [yes]
master_file    : char(255) ? [Master] ~/Master
delta_line     : int       ? [1]
delta_sample   : int       ? [1]
channels       : int (  5) ? [1 2 3 4 5] 4
raw pass disk: Processing pass 7
Actual size is 684 lines by 459 samples.

[2]% aes_ice n12.93238.0225
ld.so: warning: /usr/lib/libc.so.1.7 has older revision than expected 8
n12.93238.0225: only 1 AVHRR channels present

11858E0653: writing ephemeris data
$( BOF NOAADATA  260893 0225
$( NOAADATA  WHX   260893 0227 EPHEM  NOAA12 11858
930826022517296 00000131 01334001 26691387 09865026 01958168 07192854
$) NOAADATA  WHX   260893 0227 EPHEM  NOAA12 11858
$) EOF NOAADATA  260893 0225

1185840653: writing avhrr_ch4 data
$( BOF NOAADATA  260893 0225
$( NOAADATA  WHX   260893 0227 IMAGE  NOAA12 11858 4 0684 1582 0459 08717296 238 00010
1185840653: Image record size: 653
$) NOAADATA  WHX   260893 0227 IMAGE  NOAA12 11858 4 0684 1582 0459 08717296 238 00010
$) EOF NOAADATA  260893 0225