Online Quiz 1: QDB2033 Geospatial and Remote Sensing

What is Remote Sensing primarily concerned with?

• Observing objects at a distance without contact

• Using only visual observation techniques

• Observing objects through physical contact

• Collecting data only from ground-based sensors

Answer explanation

Remote Sensing is primarily concerned with observing objects at a distance without contact, utilizing various technologies to gather data from afar, unlike the other options which involve direct observation or contact.

Which of the following is a limitation of ground-based platforms?

• They are limited to roads and small areas

• They can be easily transported

• They can be used in any weather condition

• They provide high-resolution imagery

Answer explanation

Ground-based platforms are restricted to existing roads and small areas, limiting their operational range compared to aerial or satellite options. This makes them less versatile for large-scale surveys.

What type of platform is primarily used for collecting detailed images from the air?

• Ground-based platforms

• Mobile hydraulic platforms

• Space-borne platforms

• Airborne platforms

Answer explanation

Airborne platforms are specifically designed to collect detailed images from the air, making them the correct choice. Ground-based and mobile hydraulic platforms do not operate in the air, while space-borne platforms are used for satellite imagery.

What is a characteristic of geostationary satellites?

• They orbit at a height of 700-800 km

• They maintain a fixed position relative to the Earth's surface

• They have a 90-minute orbit period

• They are used for high-resolution imaging

Answer explanation

Geostationary satellites orbit at approximately 35,786 km above the equator, allowing them to maintain a fixed position relative to the Earth's surface. This characteristic is crucial for communication and weather monitoring.

Which airborne platform has the advantage of high spatial resolution?

• UAV/Drone-based platforms

• Balloon-based platforms

• Aircraft-based platforms

• Ground-based platforms

Answer explanation

UAV/Drone-based platforms offer high spatial resolution due to their ability to fly at lower altitudes and capture detailed imagery, making them superior for applications requiring precise data collection compared to other airborne platforms.

What is the primary function of Weather Surveillance Radar?

• To provide high-resolution imagery of the ground

• To measure atmospheric pressure

• To detect and track typhoons and cloud masses

• To collect data on land use

Answer explanation

The primary function of Weather Surveillance Radar is to detect and track typhoons and cloud masses, providing critical data for weather forecasting and monitoring severe weather events.

What is a disadvantage of using aircraft-based platforms?

• They are limited to low altitudes

• They are less mobile than ground-based platforms

• They require permission to intrude into foreign airspace

• They cannot cover large areas

Answer explanation

A key disadvantage of aircraft-based platforms is that they require permission to enter foreign airspace, which can limit their operational flexibility and effectiveness compared to other platforms.

Which of the following satellites is known for its C-Band SAR data continuity?

• AVHRR

• NOAA-19

• Sentinel-1

• Landsat

Answer explanation

Sentinel-1 is known for its C-Band Synthetic Aperture Radar (SAR) data continuity, providing consistent and reliable data for various applications, unlike AVHRR, NOAA-19, and Landsat which serve different purposes.

What is the altitude range for balloon-based platforms?

• 36,000 km

• 22-40 km

• 400 km

• < 3 km

Which type of satellite orbit is characterized by an inclination of approximately 98.7 degrees?

• Low Earth orbit

• Sun-Synchronous/polar orbit

• Geosynchronous orbit

• Geostationary orbit

Answer explanation

A Sun-Synchronous or polar orbit has an inclination of approximately 98.7 degrees, allowing the satellite to pass over the same points on Earth at the same local solar time, making it ideal for Earth observation.