Event Detection and Reporting. The detection of an 
event may be internal. A function is used to update the 
status vector and to check the event-detection criteria. 
An external agent can perform event detection. The 
agent receives status reports and detects changes in the 
state of the object. Once an event is detected, a report is 
generated that contain information such as the event 
identifier, type, priority, time of occurrence, and the 
state of the object before and after the event. Event 
reports may also contain values of other application- 
specific status variables. 
Trace Generation. To describe the dynamic behavior of 
an object or a group of objects over a period of time, 
event and status reports are recorded in time order as 
monitoring traces. Such traces may be used for 
postmortem analysis. There are two kinds of traces. A 
complete trace contains all the monitoring reports 
generated by the system since the beginning of the 
monitoring session. A segmented trace is a sequence of 
reports collected during a period of time. 
7.4 Information Processing 
After monitoring information is generated, it must be 
processed. A monitoring service provides various 
functional units as the followings. These units can be 
combined in different ways to suit the monitoring 
requirements. 
Trace Processing. Monitoring traces may be 
constructed and ordered in various ways to provide 
different logical views of system activity over a period 
of time. The selection criteria in determining how 
monitoring traces are processed are in the followings. 
(1)Generation, arrival time stamp, and other features of 
report. 
(2)Identity, priority, and other features of reporting 
entity. 
(3)Identity and type of the managed object to which the 
report refers. 
Information Validation. Performing validation and 
plausibility tests on monitoring information to make 
sure that the system has been monitored correctly is 
another important monitoring activity. Validation is 
performed according to certain validation rules. 
Database Updating. Valid monitoring information is 
used to maintain and update a representation of the 
current status of a rural land system. A conceptual 
database model of rural land system is constructed and 
continuously updated to represent the current status of 
the rural land system. There are two general 
approaches to collecting the data for database updating 
as the followings. 
(1)Dynamic approach: user queries result in the 
automatic operation of relevant sensors in 
monitored objects, which collect the required data. 
(2)Static approach: All possible monitoring data are to 
be collected and stored for potential access by users. 
The collection of data is independent of its use. 
Information Combination. The combination is to 
increase the level of abstraction of monitoring data. 
With the help of the process, users can observe the 
behavior of the system at a desired level of detail. Thus, 
low-level primitive events and states are processed and 
interpreted to give a higher-level view of complex 
states and events. 
Filtering and analysis. Modern management systems of 
rural land use may produce thousands of alarms per 
day, making the task of real-time performance 
surveillance and fault management difficult. Due to the 
large volume of alarms, system operators frequently 
overlook or misinterpret them. To reduce the number of 
alarms displayed on operators’ terminal, the 
management systems of rural land use apply alarm 
filtering procedures. On the other hand, management 
systems of typical rural land use generate large 
amounts of monitoring information. This results in 
heavy wage of computation resources. Filtering is the 
process of minimizing the amount of monitoring data 
so that users only receive desired data.at a suitable level 
of detail. 
7.5 Dissemination and Presentation 
Monitoring reports generated by objects are forwarded 
to different users of such information, including human 
users, managers, other monitoring objects and 
processing entities. Several presentation techniques of 
ArcView 2.1 (ESRI, 1994) can be used in generalized 
systems to display configuration, performance and 
other information. 
8. CONCLUSIONS 
One of effective methods for solving the problem of 
monitoring rural land use is to look into a new theory 
and related method for designing a framework for 
implementing the monitoring under complex rural land 
use environment. Thus, an approach to monitoring 
rural land systems is developed to study the principle 
and application of monitoring model to design and 
implement the monitoring system. The monitoring 
model concept and its definition are two keys to design 
and implement the system. Research results for the 
model indicate that this new approach has also many 
other advantages such as simple model construction 
process, easy correctness verification, management and 
maintenance of the model, and easy integration with 
196 International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 
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