Question

1. What do you understand by Global Navigation Satellite System and Remote Sensing Satellites? How are they similar and how are they different?

2. From the online sources please find two geospatial databases in the field you are interested in. Please provide the name and link to the dataset. Please use information available on the website to describe them based on the following characteristics

a. Source (Which organization collects it and how?)

b. Coverage (Global vs. national vs. local, only for state of Oregon?)

c. Scale (resolution of the data, smallest unit)

d. Data type (raster or vector)

e. Potential use (weather prediction, demographic analysis, land use assessment, water quality, politics, etc.)

Answer 1

​​​​​​1. Global navigation satellite system(GNSS) is a system that uses satellite to provide geospatial positioning of an object or place

With the GNSS we can get latitude, longitude, elevation with higher accuracy of an object or place by transmitting radio signals along the line of sight

  REMOTE SENSING SATELLITES are the satellites which get information about the object without making any physical contact

Remote sensing satellites uses electro magnetic radiation

Remote sensing satellites are of two types

They are 1) active remote sensing satellites

2) passive remote sensing satellites

In active remote satellites, signal is emitted by satellite to object and it's reflection is detected by sensor

In passive remote sensing satellites, reflection of sunlight is detected by sensor. It means here sun is used as source of energy