GeoSpatial Knowledge Hive

Laser Scanning                                                 Laser surveying, or 3D laser scanning is very simple in principle. A laser scanner is mounted on a tripod next to the area to be scanned. The scanner fires a laser and measures the time it takes for the laser to be reflected back, with which it can calculate the distance from the reflected point. The scanner systematically sweeps the room with these measurements until it has a complete picture of the 3-D space around it. This collection of measurements is called a point cloud, and is the data set from which we can extract valuable information and 3-D models. Image by  Defence-Imagery  from  Pixabay   Types: Aerial (or airborne) Terrestrial, mobile   Desktop (or benchtop) Hand scanning Terrestrial Application of Laser Scanning Laser scanning is used in architecture, engineering, construction, manufacturing plants, airports, hospitals, bridges, offshore platforms, virtual reality, heritage prese

Natural Disaster is natural destruction in a society in form of :    Floods ·          Earthquake ·          Forest Fire ·          Hurricane ·          Volcanic Eruptions ·          Landslides ·          Drought Image by WikiImages from Pixabay Earthquake : For earthquake post disaster study we need to have high spatial resolution satellite image. High Spatial Resolution: Small pixel size indicates high spatial resolution and greater details. Reason: If we want to classify houses on basis of partially damaged, fully damaged we need to closely observe our AOI, to see damaged bridge we need to see it as close as we can ,as detailed as we can Flood s: For flood study, we need to have data with high temporal resolution. High Temporal Resolution: How frequent an area is being observed is its temporal resolution. Reason: Floods may be progressive or flash, let’s take example of progressive flood first, after every small time period we need to know how m

History of GNSS and GLONASS A   satellite navigation is a system of satellites that provide geospatial positioning with global coverage. It allows   receiver to determine  longitude ,   latitude , and   altitude. Glonass Satellite Sensor Early sensors were the ground based   DECCA ,   LORAN ,   GEE   and   Omega   radio navigation   systems, which used terrestrial   longwave radio   transmitters   instead of satellites.  Modern systems are more direct. The satellite uses an   atomic clock   to maintain synchronization of all the satellites in the constellation.  GLONASS is the global navigation satellite system developed by Russia . The first ever satellite launched by mankind was SPUTNIK by former Soviet Union in 1957.  The first navigation satellite launched was Cosmos-192 on November 23, 1967. It had a positioning accuracy of 250-300 meters.  In 1976 the work on creating the system known as GLONASS began. GLONASS stands for GlobalnayaNavigatsionnayaSputnikovaya

GeoEye-1 SPATIAL RESOLUTION 0.41 meter Panchromatic, 1.65 meter Multispectral TEMPORAL RESOLUTION < 3 days RADIOMETRIC RESOLUTION 11 bits per pixel FREE/COMMERCIAL COMMERCIAL INCLINATION ANGLE 98 Degree No Of Band Name Of Band Range 1 Panchromatic 0,450 – 0,800 µm 2 Blue 0,450 – 0,510 µm 3 Green 0,510 – 0,580 µm 4 Red 0,655 – 0,690 µm  5 NIR 0,780 – 0,920 µm Major Area of Application: ü   Topographic mapping ü   Land use/Land cover mapping ü   National and homeland security ü   3D terrain visualization ü   Insurance and risk management ü   Natural resources and environmental monitoring Image by Free-Photos from Pixabay Worldview  1 SPATIAL RESOLUTION 0.6 meter TEMPORAL RESOLUTION 1