---
title: "Flight planning, merits and limitations"
subject: "Surveying II"
chapter: 7
key: "semester_4/surveying_ii:flight-planning-merits-limitations-photogrammetry"
source: https://www.bctengineer.com/q/semester_4/surveying_ii/flight-planning-merits-limitations-photogrammetry
site: BCT Engineering
---

# Flight planning, merits and limitations

Surveying II · Chapter 7: Photogrammetry and Remote Sensing

- Asked in: 2076 Baisakh, 4 marks
- Video: [FLIGHT PLANNING IN PHOTOGRAMMETRY](https://www.youtube.com/watch?v=S6IgSMSqXOw) — Ekta Dwivedi
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_4/surveying_ii/flight-planning-merits-limitations-photogrammetry
- Whole chapter: https://www.bctengineer.com/md/semester_4/surveying_ii/chapter-7

## Question

What are the consideration of flight planning and explain merits and limitation of photogrammetry.

## Short answer

Flight planning considers photo scale, overlaps (60% end, 25-30% side), flying height, ground control layout, weather, and aircraft/camera specs. Merits: rapid large-area mapping, permanent record, safe access to difficult terrain. Limitations: high cost, weather dependence, need for ground control, hidden details under vegetation and shadows.

## Answer

#### Considerations in flight planning
- **Purpose, scale and accuracy:** decide the photo scale $S = f/H$, the camera focal length and the flying height $H = f/S$.
- **Area and flight lines:** draw parallel strips, usually along the longer side, to reduce turns.
- **Overlap:** end lap about 60 % and side lap about 25–30 %.
- **Air base and number of photos:** computed from the ground coverage per photo and the overlaps.
- **Ground control:** planned and signalised before the flight.
- **Weather and season:** clear sky, no haze, minimum cloud shadows; sun angle of about 30–40°; low foliage season if the ground is to be seen.
- **Aircraft and camera:** speed, endurance, stability, tilt below 3°, and navigation (GPS).
- **Cost and time:** economic block layout to minimise flying time.

#### Merits of photogrammetry
- Fast and economical for large areas.
- Gives a permanent record and uniform accuracy.
- Maps inaccessible or dangerous areas safely.
- Many products from one set of photos: maps, DEMs, orthophotos.

#### Limitations
- Costly equipment and trained staff; not economical for small areas.
- Weather dependent; hidden areas under trees, shadows and buildings.
- Ground control and field checking are still required.
- Accuracy is affected by tilt, relief displacement and camera quality.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Flying height is found from:
   A. H = fS
   B. H = f/S
   C. H = S/f
   D. H = f+S
   Answer: B. S = f/H. (Key point: Flying height planning)

2. Preferred sun angle:
   A. 90 deg
   B. 5 deg
   C. 0 deg
   D. 30-40 deg
   Answer: D. Avoids long shadows. (Key point: Sun angle)

3. A merit of photogrammetry:
   A. Best for small plots
   B. Fast, economical for large areas
   C. Weather independent
   D. Needs no staff
   Answer: B. Large areas and many products. (Key point: Merit)

4. A limitation:
   A. Cannot make maps
   B. Needs no control
   C. Perfect accuracy
   D. Hidden areas under trees, shadows, and buildings
   Answer: D. Ground control and field checks still required. (Key point: Limitation)

## Related in Surveying II

- [Short note: Photogrammetry limitation and uses](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Aphotogrammetry-limitations-uses) — Surveying II, chapter 7

## Related in other subjects

- [Planning need, tools, bar chart limitations](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Aplanning-necessary-tools-bar-chart-limits) — Project Engineering, chapter 3
- [Merits and demerits of interconnected system](https://www.bctengineer.com/question.md?key=semester_5%2Fpower_system_analysis_ii%3Ainterconnection-merits-demerits) — Power System Analysis II, chapter 1, asked 3×
- [Planning electrical installation of industrial building](https://www.bctengineer.com/question.md?key=semester_6%2Findustrial_power_distribution_and_illumination%3Aplanning-industrial-installation) — Industrial Power Distribution and Illumination, chapter 5
- [Planning in dynamic environment; linked bar chart](https://www.bctengineer.com/question.md?key=semester_7%2Fproject_engineering%3Aplanning-necessary-dynamic-linked-bar) — Project Engineering, chapter 3