Compass Navigation Satellite

March 16, 2009 by airianto  
Filed under COMPASS, GNSS, Geomatics Science


Compass Satellite

The Compass system (also known as Beidou-2, BD2) is a project by China to develop an independent global satellite navigation system. Compass is not an extension to the previously deployed Beidou-1, but a new GNSS system similar in principle to GPS and Galileo.

The new system will be a constellation of 35 satellites, which include 5 geostationary orbit (GEO) satellites and 30 medium Earth orbit (MEO) satellites, that will offer complete coverage of the globe. The ranging signals are based on the CDMA principle and have complex structure typical to Galileo or modernized GPS. Similarly to the other GNSS, there will be two levels of positioning service: open and restricted (military). The public service shall be available globally to general users. When all the currently planned GNSS systems are deployed, the users will benefit from the use of a total constellation of 75+ satellites, which will significantly improve all the aspects of positioning, especially availability of the signals in so-called “urban canyons”. The general designer of Compass navigation system is Sun Jiadong, who is also the general designer of its predecessor, Beidou navigation system.

Read more

Low Latitude Troposphere: A Preliminary Study Using GPS CORS Data in South East Asia

January 1, 2009 by airianto  
Filed under GPS, Geomatics Science

Hot and wet conditions in the equatorial or low latitude region degrade satellite positioning accuracy noticeably. The degradation is related to the strong tropospheric effect, especially the wet component which is approximately proportional to the content of water vapor in the troposphere and thus makes satellite positioning more challenging in this region.

Despite the efforts to achieve better understanding of the signal delay in the low latitude troposphere, much more still remains to be improved.

Read more

Google Mengontrak GeoEye-1

September 9, 2008 by airianto  
Filed under Geomatics Science, Remote Sensing

GeoEye Satellite

Google mendapatkan hadiah ulang tahun yang ke-10 berupa peluncuran satelit yang bernama GeoEye-1. Peluncuran tersebut hanya berselang sehari menjelang ulang tahun Google. Di harapkan dengan di luncurkan GeoEye-1, Google dapat menambahkan data-data peta satelit dari seluruh dunia. Satelit GeoEye-1 diluncurkan dengan menumpang roket Delta II di tempat peluncuran Vandenberg Air Force Base.

Read more

What Are LIDAR Data?

May 15, 2008 by airianto  
Filed under Geomatics Science, LIDAR

Light Detection and Ranging (LIDAR) is a remote sensing system used to collect topographic data. This technology is being used by the National Oceanic and Atmospheric Administration (NOAA) and NASA scientists to document topographic changes along shorelines. These data are collected with aircraft-mounted lasers capable of recording elevation measurements at a rate of 2,000 to 5,000 pulses per second and have a vertical precision of 15 centimeters (6 inches). After a baseline data set has been created, follow-up flights can be used to detect shoreline changes.

How LIDAR Data Are Collected

For the South Carolina project, a LIDAR sensor was mounted on-board a NOAA DeHavilland Twin Otter aircraft pictured below. Once in flight, the aircraft travels over the beach at approximately 60 meters per second. During the flight, the LIDAR sensor pulses a narrow, high frequency laser beam toward the earth through a port opening in the bottom of the aircraft’s fuselage. The LIDAR sensor records the time difference between the emission of the laser beam and the return of the reflected laser signal to the aircraft.

Read more

Dusun Kemit Pada Google Map / Foto Satelit

May 15, 2008 by airianto  
Filed under Geomatics Science, Remote Sensing

Kemit adalah nama salah satu Dusun di Desa Grenggeng, Kecamatan Karanganyar, Kabupaten Kebumen, Propinsi Jawa Tengah. Dari dusun inilah saya berasal.
Pasar Kemit, brug Kemit, dan tugu Kemit adalah tempat-tempat spesifik saya kecil bermain sekitar tahun 1973-an. Kenapa saya bilang antara tahun 1973-an, adalah karena sebenarnya waktu itu orang tua bertugas/dinas di Irian Barat sejak tahun 1963 s/d tahun 1977. Nah pada 1973-an itulah orang tua cuti cukup lama di kampung asal kami, yaitu dusun Kemit.
Kebetulan sekali dusun saya ini telah terpotret oleh satelit dan disajikan dengan sangat baik oleh Google Map berikut ini.
Read more

« Previous PageNext Page »