169 
! capabilities, 
a is therefore 
system can be 
it disc, memory 
and process a 
11 provide the 
the: 
the data 
rare 
3 on CCT 
5 presentation, 
/e display of 
oth satellites 
graphic kit, 
:o enable the 
the LANDSCAN 
Liable to other 
an X25 network. 
Earthnet/SPOT 
order handling 
aeries 
system. The following aspects are covered: 
- Hardware 
- Software 
- Input Data 
Output Data. 
3.3.2 Hardware 
This section describes the hardware used for the 
LANDSCAN 2000 central site system which has been 
developed on a DEC VAX computer system. The 
configuration of the hardware is as follows: 
VAX 8300 
- 8 Mbytes of memory 
- 2 Magnetic Tape Units (6250 bpi) 
- 1 456 MByte Winchester disc drive unit 
- 1 RA80 Disc drive unit 
- 1 Console 
- 3 Terminals 
- 1 Multi Port Board 
- 2 GEMS Image processing system. 
- 4 1024 x 1024 by 8 bit memory planes 
4 1024 x 1024 by 1 bit overlay plane 
1 Cursor generator 
Hardware zoom (x1, x2, x4, x8) 
- Hardware roam 
- Trackball 
- Alternate function button 
Real time switching of RGB planes 
- RGB Lookup Tables. 
3.3.3 Software 
All images received and processed by the 
system that can be archived on magnetic tape 
CCT 
Data over X25 links to remote sites. 
4 IMAGE PROCESSING AND ALGORITHMIC OPERATIONS 
4.1 Overview 
This section describes the image processing and 
algorithmic operations that form the core of 
LANDSCAN, plus the additional processing and 
algorithms needed to interpret the GIS in LANDSCAN. 
The work presented here is based upon algorithms and 
techniques published in open literature on the 
subject of Remote Sensing. 
To provide a complete list of references would be 
a large task, therefore a selection of the key 
references, on which this work is based is supplied 
at the end of the Section, General introductions to 
this subject can be found in Barrett and Curtis 
(1982), Pratt (1978) Swain and Davis (1978), and 
Williams (1979), Sloggett and Williams (1986). 
4.2 The landscan library 
The algorithms used in LANDSCAN will make extensive 
use of a library of image-processing routines that 
are available on a general suite of subroutines in 
the package. 
The advantage of a modular approach is that it 
allows the same subroutines to be used by different 
processes within LANDSCAN. 
'ied in a user 
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ure development 
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iare and system 
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ace has been 
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This section lists the software to be used in the 
system. This includes: 
Operating System 
GEMLIB* Software package 
A library of image processing software 
routines 
- applications software for landscan: 
* c GEMLIB is a copyright of GEMS of 
Cambridge, Limited 
3.4 INPUT DATA 
This section covers those types of data that are 
input to the LANDSCAN system. The data supported by 
this system includes: 
- Recorded (Archived) Data on CCT 
- LANDSCAN derived data 
- Land Contour Data 
- Landsat Data (MSS and TM) 
SPOT data 
- TIROS-N data (Tromsoe exchange format) 
- METEOSAT data (ESA exchange format) 
SEASAT data 
System Software 
- Console and terminal input 
- System Management 
- System Operation 
System Control Data 
Calibration data 
Command file data (Product Generation) 
Data from on-line catalogue via X25 links 
(e.g. SPOT). 
3.5 Output data 
This section covers those types of data output from 
the system. These include: 
The algorithms used in the LANDSCAN system are 
listed below. Where the algorithm is part of the 
GIS design it is indicated by GIS after the 
description: 
Calibration 
Calculation of image transformation 
- Map Transformation 
- Image sampling 
LUT control 
- Image Transforms 
Filters 
- Operations on objects 
- Arithmetic operations 
Histogram plot 
- Statistical analysis 
Classification (i) Training 
- Classification (ii) Classify 
Overlay control 
- Deconvolution 
Generating monospectral images 
Animation 
Digital map input and formatting (GIS) 
Transformation of Vector data (GIS) 
Vector-raster conversion (GIS) 
- Raster-vector conversion (GIS) 
- Contour to surface interpolation (GIS) 
Terrain model analysis (GIS) 
Interpretation of stereographic images (GIS). 
4.3 Specific image manipulation facilities 
Image manipulation functions available to the 
operators from the workstations include: 
Classification and training 
Box 
Parzen window 
- Minimum distance 
Mahalanobis 
Maximum likelihood 
- 
Image Display 
- 
Registration 
11 hardware and 
- 
Console and terminal output 
Using 
ground control points 
the LANDSCAN 
- 
Image Hard copy 
- Three 
available resampling