UNISPACE III - ISPRS Workshop on 
“Resource Mapping from Space” 
9:00 am-12:00 pm, 22 July 1999, VIC RoomB 
Vienna, Austria 
ISPRS 
support of a data base of images (ScanEx Catalogue 
Manager), 
transfonnation of the images into geographic 
projections (Image Transformer), 
thematic image processing (ScanEx NeRIS). 
'Resurs Receiver’ application (Windows 95/NT). The 
application performs the following functions: 
tests the station, 
calculates a schedule of the satellite passages through 
the station visibility zone, 
controls the entire system and data stream during a 
reception sessioa and in particular: 
controls the antenna in accordance with a pre 
calculated track and measured input signal levels, 
locates bit sequences identifying raster image scan 
lines in the input stream, 
records properly aligned data to a hard disk, 
partly displays the data as an image in the application 
window, 
indicates the input signal level, 
indicates the station current status (time, an amount of 
recorded data, free disk space, status of a bit and frame 
synchronization, current antenna position, tracking 
errors, etc.), 
corrects the pre-calculated track in auto-track mode. 
All ballistic calculations (scheduling, antenna tracking) are 
carried out from standard NORAD-TLE orbital elements 
available in the Internet. Acceptable are elements of up to 10 
days age. 
To calculate a schedule, a user must point out a TLE file name 
and time brackets for the schedule (up to 10 days) in the 
application options. The schedule is displayed in the application 
window. The user can edit it - select passages to receive, specify 
a transmission mode for every passage. The schedule can be 
saved as a text file and afterwards - until it is expired - can be 
loaded into the application from this file. 
After the application is loaded and the schedule is loaded into the 
application, the program permanently compares the current time 
with the start time of the closest passage. In the proper time, the 
application activates itself (if it is in a background by the 
moment) and starts the reception procedures: controls the 
antenna, reads data from the interface, checks the data for the 
image identifiers and - after the identifiers are found - records 
and displays the data. 
Taking into account an age and quality of practically available 
ephemeredes, the track calculation accuracy is usually not 
sufficient to keep a satellite witliin the antenna beam during the 
whole passage. Therefore the application has so-called "auto 
tracking" mode. In this mode, the application periodically shifts 
the antenna position from a calculated one in different directions 
by a small angle. Statistically analyzing a dependence of the 
input signal level on the shift direction, the application corrects 
the pre-calculated track. 
The reception can be stopped by the user's command or 
automatically - if no image identifiers are found in the input data 
during a certain time. If the signal is accidentally lost and a 
passage is not over, the reception can be immediately restarted. 
In this case the application sets the antenna to a position 
corresponding to the current time, opens a new file to record 
data, searches again for the image identifiers and so on. 
Actually, the only user's duty after the schedule is calculated is to 
observe the image quality at the PC display and stop the 
reception when the quality falls down at the end of a track (or 
restart the reception in case of an accidental loss of signal). Of 
course, the application can do it itself but it needs perceptibly 
more time (and therefore - the disk space) to make a decision. 
Received data are written into a file as a raster type image with 
an extendable header. The header contains a usual list of the 
image characteristics (a number of lines, number of pixels in a 
line, number of spectral cliannels, start time, satellite name, 
imaging mode, etc.). Besides, the satellite orbital elements are 
written in the header in a binary representation for georeference 
purposes (see also descriptions of ScanViewer and Catalogue 
Manager). 
Also we would like to send you more detail information about 
ScanViewer, Catalogue Manager applications and the 
information concerning the operational work with ScanER 
receiving station. 
'ScanViewer' application (Windows 95/NT). The application 
is intended in the first place to look through an image, assess its 
quality and contents, select and save fragments for the following 
storage and thematically processing. 
The application enables to: 
get a detailed annotation of an image file, 
view any rectangular fragment of an image with an 
arbitrary' sample step in a gray-scale, pseudo-color or 
"true color" (three-channel) representation, 
locate an image geographically and overlay a map onto 
the image, 
correct the geographical location using unambiguously 
distinguishable objects in the image, 
save any rectangular fragment of an image to a new file 
of the same format (thus making all of the ScanViewer 
functions applicable to this file), 
print any image window and export it to a Windows 
bitmap format file, 
export image into Image Transformer application. 
A size of a loaded image fragment and number of simultaneously 
loaded fragments (i.e. image windows) are restricted only with 
the available memoiy. 
A geographical reference as calculated from the satellite orbital 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII Part 7C2, UNISPACE III, Vienna, 1999 
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