Difficulty: Easy
Correct Answer: All of these
Explanation:
Introduction / Context:
Global Positioning System (GPS) and other GNSS constellations underpin modern positioning. From field mapping to turn-by-turn navigation and high-precision orbit determination, GNSS provides scalable accuracy with receivers ranging from handheld to geodetic grade.
Given Data / Assumptions:
Concept / Approach:
GNSS delivers positioning by trilateration using satellite pseudoranges and carrier phases. For GIS, handheld/receiver solutions streamline coordinate capture. For navigation, continuous fixes guide movement. For precise orbit determination, carrier-phase measurements and dynamic models estimate spacecraft state vectors to centimetre-level accuracy.
Step-by-Step Solution:
Verification / Alternative check:
Published performance reports show sub-metre mapping with SBAS and centimetre-level survey with RTK/PPP; multiple LEO missions use onboard GNSS for precise orbit determination.
Why Other Options Are Wrong:
“None” contradicts extensive operational use; choosing a subset ignores established capabilities.
Common Pitfalls:
Assuming one accuracy fits all; forgetting augmentation requirements; ignoring multipath/obstruction effects.
Final Answer:
All of these
Discussion & Comments