About this previous year paper
Course: B.Tech (ECE, Semester IV)
Subject Code: ECE402
Subject Title: Geoinformatics
Exam Type: Theory
Duration: 3 Hours
Maximum Marks: 100
Year: 2016–17
The paper evaluates a student’s grasp of photogrammetry, remote sensing, GIS (Geographic Information Systems), and GPS (Global Positioning System) concepts — all vital in modern spatial analysis, telecommunications, and satellite systems.
SECTION – A (10 × 2 = 20 Marks)
Short, conceptual definitions or explanations — testing precision and clarity.
Topics:
a) Stereoscopy: Technique for perceiving 3D depth by viewing overlapping aerial photographs from two perspectives.
b) Relief Displacement: Apparent shift in object position due to height variation from the ground datum.
c) Parallax: Apparent change in object location when viewed from different positions; crucial for height measurement in stereo pairs.
d) Active Remote Sensing: Uses self-generated energy (e.g., RADAR, LiDAR).
e) Passive Remote Sensing: Uses reflected solar radiation (e.g., Landsat, IRS).
f) Flight Planning: Determining altitude, overlap, and camera orientation for aerial surveys.
g) Sun-synchronous Satellites: Orbit passes over same local time daily, ideal for mapping and imaging (e.g., IRS, Landsat).
h) Geo-synchronous Satellites: Stay fixed relative to a point on Earth (e.g., INSAT).
i) Resolution: Ability to distinguish small details — includes spatial, spectral, temporal, and radiometric resolution.
j) Spectral Reflectance Curve: Graph showing reflectivity of surfaces across wavelengths; helps identify vegetation, soil, and water.
SECTION – B (Attempt Any 5 – 5 × 10 = 50 Marks)
Analytical and descriptive questions linking photogrammetry, remote sensing, and GIS.
Topics:
(a) Derivation of Scale of a Vertical Photograph:
Scale=fH−h\text{Scale} = \frac{f}{H - h}Scale=H−hf
and method for determining ground coordinates and distances from photo measurements.
(b) Derive Relief Displacement Expression:
d=r×hHd = \frac{r \times h}{H}d=Hr×h
and discuss its influence on aerial photo interpretation.
(c) Numerical Problem:
Given:
Focal length = 37.5 cm
Height = 7200 m
Overlap = 50%
Print size = 22.5 × 22.5 cm
Ground level = 2500 m above MSL
Find: (i) Scale of photograph, (ii) Airbase length.
(d) Information Extraction from Aerial Photograph:
Visual: tone, texture, pattern, shape, shadow, size.
Digital: classification, contrast enhancement, spectral analysis.
(e) Satellite Image:
Definition, characteristics (spatial & spectral), and common data formats (GeoTIFF, HDF, NetCDF).
(f) Image Enhancement:
Improving interpretability via contrast stretching, histogram equalization, filtering, or edge detection.
(g) Land Use/Land Cover (LULC) Classification:
Categorizing terrain into forest, agriculture, built-up, water, barren land.
Methods: supervised and unsupervised classification.
(h) GIS (Geographical Information System):
Definition, components (hardware, software, data, methods, people), and applications:
Urban planning, resource management, telecom tower optimization, navigation, and disaster mapping.
SECTION – C (Attempt Any 2 – 2 × 15 = 30 Marks)
Applied understanding of GPS systems and satellite navigation.
(3) Segments of GPS:
Space Segment: Satellite constellation (24+ satellites in 6 orbital planes).
Control Segment: Ground monitoring stations for orbit tracking and error correction.
User Segment: GPS receivers converting satellite signals into position, velocity, and time data.
(4) Kinematic vs Differential GPS:
| Parameter | Kinematic GPS | Differential GPS |
|---|---|---|
| Motion | Receiver moves (real-time tracking) | One receiver fixed as base |
| Accuracy | Few cm (RTK) | Sub-meter accuracy |
| Use | Vehicle tracking, drones | Surveying, mapping |
(5) GPS Applications and Impact:
GPS has transformed:
Navigation: Cars, aviation, shipping.
Telecom: Tower synchronization.
Agriculture: Precision farming.
Disaster Management: Rescue coordination.
Mapping & GIS: Real-time data integration.
Key Units Summary
| Unit | Title | Core Concepts |
|---|---|---|
| I | Photogrammetry | Scale, displacement, stereoscopy |
| II | Remote Sensing | Satellite imagery, spectral response |
| III | GIS | Data models, layers, applications |
| IV | GPS | Segments, positioning, accuracy methods |
| V | Integration | GIS + GPS + Remote Sensing applications |
Summary
The Geoinformatics (ECE402) exam combines engineering fundamentals with spatial data technology.
It expects students to:
Derive key formulas (scale, relief displacement).
Understand satellite principles (sun-synchronous, geo-synchronous).
Apply GPS and GIS concepts to real-world navigation and mapping.