List of top Geo Informatics Engineering Questions asked in GATE Geomatics Engineering

The error matrix resulting from randomly selected test pixels for a classified image is given below.
The Producer’s accuracy of class 1 is   % (rounded off to 1 decimal place).

 Reference Data
 Class 1Class 2Class 3Class 4
Classified DataClass 1320873
Class 21227062
Class 3964105
Class 41423350

The brightness values of four pixels in the input image are shown in the table below. The image is rectified using nearest neighbor intensity interpolation, and the pixel at location (5, 4) in the output image is to be filled with the value from coordinate (5.3, 3.7) in the input image. The brightness value of the pixel at location (5, 4) in the rectified output image is 11. (Answer in integer)

Location of pixels in input image
(Row, Column)		Brightness Value
(5, 3)9
(5, 4)11
(6, 3)14
(6, 4)12

 

In case of normalized difference vegetation index (NDVI), which of the following statements is/are correct?
A remote sensing image is acquired from an IRS series satellite. Initially a two-dimensional filter with transfer function \( H(u,v) = \exp\left(\frac{-D^2(u,v)}{2D_0^2}\right) \) is applied to reduce scan line effects. Here \( D(u,v) \) is the distance from the center of the frequency rectangle, and \( D_0 \) is the cutoff frequency. Which one of the following will be the transfer function for the corresponding filter to detect the edges in the image?

A CCD array element in a remote sensing sensor measures incoming radiation and its output voltage varies linearly between 0 V to 5 V. This voltage is converted to an 8-bit digital image using an analogue to digital convertor (ADC). The ADC has a linear response without bias or noise. If the output image pixel has a digital number of 100, the input voltage to the ADC would be __________ V (rounded off to 2 decimal places).

Clouds appear white in optical visible spectral bands of remote sensing images due to _________ scattering.

Which one of the following is NOT used to assess the quality of remote sensing image?
A remote sensing instrument measures only in Green, Red and Near-Infrared frequency bands. The remote sensing index/indices that CANNOT be derived using data of this instrument is/are: