Geographic Information System Gis

Insert the angles in the formula (all in degrees): Evaluate the terms:

Count nodes (vertices). Convert to a topological graph by placing a node at every line endpoint and at every intersection (no pseudo-nodes). The figure yields distinct nodes.
Count edges (links). An edge is the maximal line segment between two consecutive nodes along a path. Tracing each segment between nodes gives edges.
Check with Euler’s formula (planar, single component). For a connected planar graph, where is the number of faces (regions), including the exterior. With and , Thus the total number of regions is . Therefore statements (A), (B), and (C) are true; (D) is false.

P 2 (Mis-located entities).
“Digitized in the wrong place” directly describes mis-location.
Q 4 (Missing labels).
Polygons without IDs (labels) are undefined polygons.
R 3 (Artefacts of digitization).
Typical digitizing artefacts include undershoots, overshoots, bad nodes, loops, spikes.
S 5 (Duplicate labels).
Two or more IDs placed on the same polygon.
T 1 (Duplicate entities).
The same feature captured twice (points/lines/boundaries).

A 2D second-order polynomial transformation is There are coefficients for and for 12 unknowns.
Each GCP supplies two equations (one for , one for ), so the minimum number of GCPs is

(A) True. Topography (elevation/terrain) varies continuously over space and is modeled as a continuous field (e.g., raster DEM, TIN surface).
(B) True. In the geo–relational model (classic coverages/shape+DBF), geometry is stored in spatial files while attributes are stored separately in a relational table linked via a key.
(C) True. Object/feature-based (geodatabase, O-O) stores geometry and attributes together as an object (with behavior), i.e., an integrated record.
(D) False. Land surface temperature is a spatially continuous field (varies everywhere), not a discrete feature.

During digitizing/editing, software uses several distance tolerances to control feature creation and cleanup.
Snap tolerance forces vertices/edges within a set distance to coincide (avoids gaps/overshoots).
Weed tolerance removes redundant vertices closer than the set threshold (line simplification).
Grain tolerance (used in some GIS/CAD digitizers) controls the minimum spacing of sampled points while tracing, acting like a densify/sampling threshold.
“Polygon tolerance” is not a standard editing tolerance per se (area features are affected by the same snap/weed/grain settings), hence (D) is not chosen.

Reasoning.
Averaging two rasters cell-by-cell (same row/column index) produces an output raster of identical dimensions where each output cell depends only on the corresponding input cell values at the same location. This is exactly a local (per-cell) raster operation (also called map algebra).
Neighborhood uses a moving window around each cell. Zonal aggregates over zones defined by another raster. Global uses all cells at once. None of these applies here.

Overlay (e.g., Intersect, Union, Identity) operates on two or more vector layers, producing output features whose geometries are spatial combinations of inputs and whose attribute tables are merged accordingly. Buffer creates zones around features; Cartesian distance is a measurement; “Map Manipulation” is not a standard vector overlay operator.

The correct answer is (B) and (C) : Both ANN and Fuzzy C-means clustering are non-parametric classifiers AND ANN can be both supervised and unsupervised classification method

The correct answer is : 95

The correct answer is (A and B and C) : Chain code AND Run-length code AND Quadtree

The correct answer is (B) : SPLIT overlays polygons and keeps all areas in both layers.

The correct answer is : 2,4

The correct answer is (A and B and C) : Tropospheric delays AND Orbital errors AND Ionospheric delays

The correct answer is (A and B) : Total electron count in the ionosphere AND Carrier signal frequency

The correct answer is (A) : Overlaying

The correct answer is (C) : 24

The correct answer is (B) : satellite's geometry

The correct answer is (C) : Launch segment

The correct answer is (C) : Trilateration

A shapefile is a widely used geospatial vector data format for geographic information system (GIS) software. It is an example of a georelational data model, where spatial and attribute data are stored separately but linked through a common identifier. However, shapefiles do not store topological information, which means they do not explicitly record relationships such as connectivity and adjacency. Therefore, polygons may contain duplicate arcs for shared boundaries, and maintaining data integrity for topological relationships requires additional processing or storage formats like geodatabases. Hence, the statement in option (B) is not correct, making it the correct answer for this question.

To identify the houses affected by pollution within 500 meters of the stream, two GIS vector operations are required:

1. Buffer: Create a 500 m buffer around the stream (line feature) to represent the impact zone of pollution.

2. Overlay: Perform an overlay (such as intersection) of the buffer zone with the polygons representing houses to extract only those houses that fall within the buffer area.

Hence, the correct combination of operations is Buffer and Overlay.

Step 1: Understanding the Concept:
In Geographic Information Systems (GIS), real-world features are represented digitally using two primary data models: Raster and Vector.
Step 2: Detailed Explanation:
1. Vector Data Model: This model uses discrete geometric primitives to represent objects with distinct boundaries.
- Points: Represented by a single X, Y coordinate (e.g., a well, a light pole).
- Lines (Polylines): Represented by a sequence of connected points (e.g., a road, a river).
- Polygons: Represented by a closed sequence of connected points forming an area (e.g., a lake, a land parcel).
2. Raster Data Model: This model represents the world as a grid of cells or pixels, where each cell contains a value representing information (e.g., satellite imagery, elevation maps).
Step 3: Final Answer:
The Vector model is the one that uses points, lines, and polygons to represent geographic features.