Your Answer : (Not Answered)

Correct Answer : A

Significant wave height is determined by the Radar Altimeter.

A satellite radar altimeter sends short microwave pulses straight down and times their return. Over a rough sea the pulse returns from crests before troughs, so its leading edge is stretched; the slope of that edge gives significant wave height, while the return time gives sea surface height and the strength of the echo gives wind speed. TOPEX/Poseidon, Jason and the Indo-French SARAL-AltiKa work this way.

Synthetic aperture radar and the Shuttle Imaging Radar produce images and can show wave patterns, but they are not the routine source of significant wave height. The Thematic Mapper is an optical Landsat sensor, not a microwave instrument.

Your Answer : (Not Answered)

Correct Answer : C

The basic and still widely used form of remote sensing is aerial photographs.

Remote sensing began with photographs taken from balloons and aircraft, and aerial photography remains in wide use for topographic mapping, land use surveys, forestry and urban planning, because of its high spatial resolution and the stereoscopic (three-dimensional) view that overlapping photographs give.

Radar, multispectral scanner (MSS) and hyperspectral data are later and more specialised techniques that depend on satellite or airborne sensors developed from the 1960s and 1970s onwards.

Your Answer : (Not Answered)

Correct Answer : B

The orbit described is the geostationary orbit.

A satellite in a circular orbit over the equator at about 36,000 km (35,786 km) altitude takes 24 hours (one sidereal day) to go round the Earth, the same time the Earth takes to rotate. It therefore stays fixed above one point on the equator, which suits communication and weather satellites such as India's INSAT series.

Sun-synchronous orbits are low, near-polar orbits used by remote sensing satellites, low Earth orbits are only a few hundred kilometres up, and an elliptical orbit is defined by its shape, not by matching the Earth's rotation.

Your Answer : (Not Answered)

Correct Answer : B

Objects on aerial photographs are identified by their Signature.

Every surface reflects and emits energy in its own characteristic way across wavelengths: healthy vegetation reflects strongly in the near infrared, water absorbs it, bare soil rises steadily. This spectral signature, together with tone, texture, shape and pattern, is what an interpreter uses to tell crops, forest, water and buildings apart.

Atmospheric windows are wavelength bands where the atmosphere lets radiation through, and absorption bands are where it does not; both decide which wavelengths a sensor can use, not what an object is. A radiometric error is a distortion in recorded brightness that has to be corrected, the opposite of an identification aid.

Your Answer : (Not Answered)

Correct Answer : C

Remote sensing uses electromagnetic waves.

Remote sensing gathers information about objects without touching them by recording electromagnetic radiation they reflect or emit, in the visible, infrared, thermal and microwave parts of the spectrum. Different surfaces, such as water, vegetation and soil, reflect and emit differently at different wavelengths, their spectral signatures, which lets them be identified.

Sound waves are used in sonar, which is not what remote sensing from aircraft and satellites relies on. 'Electric waves' and 'wind waves' are not the radiation sensed.

Your Answer : (Not Answered)

Correct Answer : C

The system is a GIS, a Geographic Information System.

A GIS is a computer system for capturing, storing, retrieving, analysing and displaying spatially referenced data, so it can overlay layers such as land use, soils and roads and answer questions about where things are and how they relate. The question's wording is the standard definition.

GPS, the Global Positioning System, only determines position using satellites; it collects locations but does not store and analyse spatial data. Landsat is a series of earth observation satellites that supply images. A radiometer is an instrument that measures radiant energy, a sensor rather than a data system.

Your Answer : (Not Answered)

Correct Answer : A

The term is lineament.

In remote sensing and structural geology a lineament is a mappable linear or curvilinear feature of the landscape, seen on satellite images or aerial photographs, that reflects an underlying structure such as a fault, fracture zone, joint set or dyke. Straight valleys, aligned drainage and tonal lines often mark them, and lineament maps are used in groundwater and mineral exploration.

'Linear' and 'line' are general words, not the technical term. 'Superlineament' is not a standard term; the general definition given in the question is that of the lineament itself.

Your Answer : (Not Answered)

Correct Answer : A

India's first satellite was Aryabhatta (Aryabhata).

Built by ISRO and launched on 19 April 1975 by a Soviet rocket, Aryabhata carried experiments in X-ray astronomy, solar physics and aeronomy. It gave Indian engineers their first experience of designing, building and operating a satellite, the leap the question describes.

Bhaskara (1979) was India's first experimental remote sensing satellite, IRS-1A (printed 'IRS-IA', 1988) its first operational remote sensing satellite, and CARTOSAT-2 (2007) a later high-resolution mapping satellite.

Your Answer : (Not Answered)

Correct Answer : C

From shorter to longer wavelength the order is UV, visible, IR, microwave.

In the electromagnetic spectrum, ultraviolet lies roughly at 10-400 nm, visible light at 400-700 nm, infrared from 700 nm to about 1 mm, and microwaves from about 1 mm to 1 m. So each band in the keyed sequence has a longer wavelength than the one before it (the paper's '\(\gt\)' sign marks the sequence, not a numerical comparison).

The other sequences put the bands out of order: one starts with IR and puts UV after microwaves, another puts microwaves first, and the last puts visible before UV and microwaves before IR.

Your Answer : (Not Answered)

Correct Answer : A

The key's answer is Soil analysis.

GIS (Geographic Information System) layers location data on maps. In agriculture its first and most basic use is soil analysis: mapping soil type, texture, pH and nutrient status across fields so that crops and treatments can be matched to each patch of land.

Honest caution: GIS is also used to map fertilizer needs and to track pest and disease outbreaks, so options B and C describe real uses too, and the question does not say which single one is wanted. The key goes with soil analysis, the standard first application. Speed analysis (option D) is not an agricultural use of GIS, so it is clearly wrong.

Your Answer : (Not Answered)

Correct Answer : B

The 'father of GIS' is Roger Tomlinson.

Roger Tomlinson, a British-Canadian geographer, led the development of the Canada Geographic Information System in the 1960s for the Canada Land Inventory, the first computerised GIS, and coined the term 'geographic information system'.

The other names are not associated with founding GIS.