DISTRI'C'O'

1
DISTRI.C.O.

• The new GRIB distribution system at CNMCA
• Presented by Capt. Enrico FUCILE

2
Overview

• Introduction
• System requirements
• System description
• GRIB Database
• PHP Classes Library
• WEB Interface
• Future development

3
Introduction

• DISTRIbuzione Catena Operativa (Distribution
  Operational Suite)
• A kind of post-processing of the GRIB data
  produced by the numerical models is needed to
  fulfil the requests of the internal and external
  users
• Delivering of processed products to users must be
  controlled and should be easy to configure and
  modify

4
System requirements

• Transformation of GRIB data from a grid to
  another one (e.g. from a rotated lat-lon grid to
  a geographical lat-lon grid)
• Interpolation, rotation and extraction of
  single point data from a GRIB file
• Processing a large number of GRIB files

5
System requirements

• Distribution of processed GRIB to users
• Freandly graphical interface for the operator
• Easy access to system facilities through a
  scripting language
• Graphical real time control of the activities
  (processing and distribution)

6
System description
WEB client
Filesystem
WEB PHP Server Pages
PHP classes library
PHP Scripts for loading
PHP Scripts for processing
USERS
PHP Scripts for distribution
7
GRIB Database

• Represents operational production cycle
  (separation of the database in two areas static
  and dynamic)
• Implements distribution logic (users are
  important entities of the database design phase)

8
GRIB Database
Registered products (static)
Products (dynamic)
Users
9
Why PHP ?

• Simple syntax (smooth learning curve)
• Quick development (scripting language no
  compilation, weakly typed language)
• A lot of extensions available (gd, xml, network,
  DB connectivity modules)
• Easy to extend with compiled C code (easy reuse
  of existing code and easy extension with high
  performance routines for intensive calculations)

10
Why PHP ?

• Allows object oriented syntax (good code
  maintenance and extension)
• Can be used both as independent scripting
  language and embedded in a WEB server (a PHP
  class library can be used both from operational
  scripts and from Web server pages)
• It is OPEN SOURCE

11
PHP Classes Library
GRIB DECODING include(grib.inc) grib new
GRIB grib-gtWith(parameterid,11) grib-gtWith(cen
terid,80) grib-gtWith(processid,2) grib-gtWith(l
evelid,110) while (grib-gtDBGetNext())
grib-gtDecode() grib-gtPrintPDS()
grib-gtPrintGDS() grib-gtUnpack() for (i
0 ilt20 i) print
grib-gtfieldi
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PHP Classes Library
VALID PARAMETERS parameterid tableid centerid p
rocessid gridid levelid level1 level2 bitmapid
run timeid timeunitid time1 time2 latfirst lat
last lonfirst lonlast ni nj di dj latpole l
onpole rotation pojection scanmode ref_date
13
PHP Classes Library
INTERPOLATION include(grib.inc) grib new
GRIB grib-gtWith(parameterid,11) grib-gtWith(cen
terid,80) grib-gtWith(processid,2) grib-gtWith(l
evelid,110) while (grib-gtDBGetNext())
grib-gtSetNewGrid(new_grid_id)
grib-gtIntepolate() grib-gtDBPut()
14
Why WEB interface ?

• Central administration and control
• Easy access from any operating system
• Security policy (single machine access can be
  controlled through IP address)
• Apache WEB server is OPEN SOURCE
• Further development of interface can be done
  without any installation on client machines
• Scalability and portability

15
Future development

• Elaboration of gaussian grids and spherical
  harmonics
• Simple mathematical operators for GRIB objects
• Development of a tool for automatic inclusion of
  C and Fortran code into the PHP parser
• Inclusion of MAGICS routines into the PHP
  language