January 26, 2010

ArcView, ArcEditor, and ArcInfo Different

ArcView, ArcEditor, and ArcInfo Different

The ArcGIS Desktop can be accessed using three software products,
each providing a higher level of functionality. ArcView provides
comprehensive mapping and analysis tools along with simple editing and
geoprocessing tools. ArcEditor includes the full functionality of ArcView
with the addition of advanced editing capabilities for coverages and
geodatabases. ArcInfo extends the functionality of both to include
advanced geoprocessing. It also includes the legacy applications for
ArcInfo Workstation (Arc, ARCPLOT™, ARCEDIT™, and so on).


January 19, 2010

Transformasi Datum dari UTM ke LATLONG

Transformasi Datum dari UTM ke LATLONG

Transformasi datum di ArcView yang menggunakan extension Projection Utility Wizard
hanya dapat dipakai untuk shapefile tipe polygon dan line.
Untuk tipe point di ArcMap, kita dapat menggunakan
Toolbox Data Management Tools > Projections and Transformation.

1. Buka ArcMap. Klik ikon Show/Hide Arc Toolbox >
    Data Management Tool > Projections and Transformations



2. Lalu double klik Define Projection. Masukkan data yang tipenya point,
    seperti koordinat desa, kota atau lainnya. Tentukan sistem koordinatnya. OK



3. Pada layer akan muncul data layernya dan menggunakan koordinat
    UTM (lihat tanda panah merah)

January 12, 2010

GIS data conversion – overview

GIS data conversion – overview

>  In GIS Data conversion has two commonly used interpretations:  
    - when used in the narrow sense, it refers to the process of
       converting existing information to a digital format for use
       in a given GIS software package
>  In its broader interpretation,  it refers to the often
    complex process of building databases for GISs.
    - Data conversion is usually a costly and a major expenditure
      item in setting up a GIS. This situation is brought about by
      an interaction of several factors including the large quantity
      of data, data that is frequently of indifferent condition/quality
      and the complexity of the conversion task.  The data conversion
      process involves: a plan (incl. manuscript collation, preparation,
      information filtering), conversion using appropriate method,
      edits/ transformations, format conversions (if necessary) and
      data structuring (making the graphic data  more ‘intelligent’
      by building topology)
    - The general  (and accelerating) trend has been towards collection
       of data in digital format so the main conversion problem is related
       to existing data – especially true in developing countries where the
       availability of data in digital form is still very limited.
       There are many conversion methods; all are befitting from the general
       improvement  of both hardware and software used in conversion.
       Raster scanning is now playing a major role – especially as
       the first step in ‘heads-up’ digitising; however, automated data
       conversion remains a dream. Automated data conversion is where
       a map or similar data source can be scanned and all its geographic
       features and properties recognised and extracted  by smart software
       and converted into a GIS database.  It is important to recognise that
       the data conversion process can introduce significant errors – only
       some of these can be detected automatically by software
       (especially so in the case of graphical data)
    - The converted graphic data in vector packages is stored simply
       as coordinates i.e. as ‘spaghetti’ data.  This is relatively ‘dumb’
       data i.e. it has no information on spatial relationships
       (such as adjacency, intersection and connectivity).
       As such any spatial query becomes a tedious process unless
       topological structures are created.  After topology has been built,
       the system is able to respond to queries by using
       topological information rather than by a tedious processing
       of coordinate (to generate geographic
       features every time a query is made)

January 06, 2010

GIS OVERVIEW

GIS OVERVIEW

Definition of GIS
A system of hardware, software, data, people, organizations and institutional
arrangements for collecting, storing, analysing and disseminating information
about areas of the earth. (Dueker & Kjerne 1989:7-8)
“The organised activity by which people:
- Measure aspects of geographic phenomena and processes
- Represent these measurements, usually in the form of a computer database,
   to emphasize spatial themes, entities and relationships
- Operate upon these representations to produce more measurements and to
   discover new relationships by integrating disparate sources
- Transform these representations to conform to other frameworks of entities
   and relationships” (Chrisman 1997:5)

GIS as an Information System

January 03, 2010

Registrasi Peta

Registrasi Peta


Untuk meregistrasi peta jpg agar posisinya sesuai dengan koordinat bumi
maka peta jpg tersebut harus mempunyai minimal 4 titik koordinat.
Salah satu cara registrasi peta jpg yakni menggunakan extension
TerraExplorer Image Tools. Sebelumnya, Terra Explorer harus sudah
terinstall di komputer anda dan otomatis ekstensi *.avx-nya akan ada
di folder C:\ESRI\AV_GIS30\ARCVIEW\EXT32

1. Buka ArcView Gis lalu klik menu File > Extensions…
    Beri tanda centang TerraExplorer Image Tools,
    Image Analysis dan JPEG (JFIF) Image Support, OK.





2. Muncul icon TerraExplorer Image Tools. Lalu klik icon tersebut.
    Maka muncul window Image …..


3. Klik icon add control point, maka akan muncul window image Registration

January 01, 2010

Hitung luasan dan keliling polygon

Hitung luasan dan keliling polygon

Salah satu cara untuk menghitung luasan dan keliling polygon wilayah
digunakan extensions Xtools.avx
Berikut langkah-langkahnya :

1. Buka file polygon yang ingin anda hitung (disini contohnya sultra). Lalu klik menu
    File > Extensions…
    Beri tanda cek pada extensions XTools Extension-Meters/Hectares, OK



2. Maka menu command XTools akan muncul. Lalu klik XTools > Update area,
    perimeter, hectares and length.



3. Muncul window calculate feature size. Pada kolom, pilih theme sultra, OK

Crop Raster Image

Crop Raster Image

1. Open the ArcView program. Add Image Analysis extensions in
    File > Extensions > Image Analysis. Click Add theme icon then select
    raster image. Click Image Analysis > Properties …



2. Choice In the Analysis Extent drop down list and Analysis Mask drop down
    list shp polygon.



3. Click image raster theme. Then Click Image Analysis > Subset..