Datasheet

11
Manual
Detailed Outline of Data Trajectory
2.1 General
This chapter gives an overview of the complete data trajectory, starting from values measured by the station’s sen-
sor all the way till the final storage of data into the Nile Basin Database (NBD) on PC at the FPI. It presents the vari-
ous hardware and software components involved in this process, together with their interconnection. Furthermore,
it lists sequentially all user actions that play a role in the data trajectory.
2.2 Hardware
Figure 1 presents all hardware components involved in the route from sensor to PC in the hydro-meteorological data
acquisition process
Detailed Outline of Data Trajectory
The various climatological parameters are measured using electronic sensors. Depending on the nature of a
parameter, its value is represented by either a voltage or a sum of pulses.
The datalogger measures the voltages and/or counts the pulses, and transfers them to intelligible figures in
standard units, like for example degrees Celsius for temperature or mm of rainfall for precipitation. Other tasks
of the datalogger are to activate the various sensors at pre-defined intervals, and store the measurements in its
memory.
The CR10KD keyboard display is used to communicate with the datalogger on site. For instance, in case when a
user wants to invoke manual data transfer or check on operation of individual sensors, this is accomplished by con-
necting the CR10KD keyboard to storage module and logger, and by typing in on the keyboard the proper commands.
Also, when the user wants to check the performance of sensors and datalogger while onsite, this is achieved by
connecting the keyboard only to the datalogger and keying in the respective commands.
The SM4M/SM192 storage module is used to download the accumulated raw data from datalogger on site and
Figure 1: Hardware components involved in data acquisition process.
Sensors
Datalogger
Storage Module
or Short Haul
Modems
SC532A/SC932
Interface
PC
Keyboard Display or
Short Haul Modems