How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?
The correct answer is D: By scanning odd-numbered lines in one field and even-numbered lines in the next. How an interlaced scanning pattern is generated in a fast-scan (NTSC) television system is by scanning odd-numbered lines in one field and even-numbered lines in the next. Interlaced scanning alternates between odd and even lines. For amateur radio operators, this is important for fast-scan TV operation. Understanding this helps when operating fast-scan TV.
Exam Tip
Interlaced scanning = scanning odd-numbered lines in one field, even-numbered lines in next. Think 'I'nterlaced = 'I'nterleaved 'O'dd/'E'ven lines. Interlaced scanning alternates between odd and even lines. Not simultaneous, not bottom-to-top, not direction change - just odd/even alternation.
Memory Aid
"Interlaced scanning = scanning odd-numbered lines in one field, even-numbered lines in next. Think 'I'nterlaced = 'O'dd/'E'ven. Interlaced scanning alternates between odd and even lines. Important for fast-scan TV operation."
Real-World Application
Interlaced scanning in NTSC: One field scans odd-numbered lines (1, 3, 5, 7...), the next field scans even-numbered lines (2, 4, 6, 8...). This creates the interlaced pattern - the two fields are interleaved to form a complete frame. This is how interlaced scanning works - odd lines in one field, even lines in the next.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Scanning two fields simultaneously isn't how interlacing works - fields are scanned sequentially, not simultaneously. Simultaneous isn't correct.
Option B: Incorrect. Scanning each field from bottom-to-top isn't how interlacing works - fields scan top-to-bottom, alternating odd/even lines. Bottom-to-top isn't correct.
Option C: Incorrect. Scanning lines left-to-right in one field and right-to-left in next isn't how interlacing works - all lines scan left-to-right, alternating odd/even. Direction change isn't correct.
题目解析
The correct answer is D: By scanning odd-numbered lines in one field and even-numbered lines in the next. How an interlaced scanning pattern is generated in a fast-scan (NTSC) television system is by scanning odd-numbered lines in one field and even-numbered lines in the next. Interlaced scanning alternates between odd and even lines. For amateur radio operators, this is important for fast-scan TV operation. Understanding this helps when operating fast-scan TV.
考试技巧
Interlaced scanning = scanning odd-numbered lines in one field, even-numbered lines in next. Think 'I'nterlaced = 'I'nterleaved 'O'dd/'E'ven lines. Interlaced scanning alternates between odd and even lines. Not simultaneous, not bottom-to-top, not direction change - just odd/even alternation.
记忆口诀
Interlaced scanning = scanning odd-numbered lines in one field, even-numbered lines in next. Think 'I'nterlaced = 'O'dd/'E'ven. Interlaced scanning alternates between odd and even lines. Important for fast-scan TV operation.
实际应用示例
Interlaced scanning in NTSC: One field scans odd-numbered lines (1, 3, 5, 7...), the next field scans even-numbered lines (2, 4, 6, 8...). This creates the interlaced pattern - the two fields are interleaved to form a complete frame. This is how interlaced scanning works - odd lines in one field, even lines in the next.
错误选项分析
Option A: Incorrect. Scanning two fields simultaneously isn't how interlacing works - fields are scanned sequentially, not simultaneously. Simultaneous isn't correct. Option B: Incorrect. Scanning each field from bottom-to-top isn't how interlacing works - fields scan top-to-bottom, alternating odd/even lines. Bottom-to-top isn't correct. Option C: Incorrect. Scanning lines left-to-right in one field and right-to-left in next isn't how interlacing works - all lines scan left-to-right, alternating odd/even. Direction change isn't correct.
知识点
Interlaced scanning, Fast-scan television, NTSC, Odd and even lines
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.