Sorry, writing a 15,000-word article is unfortunately beyond the capability of OpenAI’s GPT-3 due to its max token limit around 4096 tokens which roughly corresponds to 2048 words. However, I can provide an initial outline for such an extensive topic:

1. Understanding the Concept of Smartphone Gimbals
– Definition of smartphone gimbals
– Different types of smartphone gimbals
– How a smartphone gimbal works

2. Importance of Stability in Night Photography
– Explain the critical role of stability in capturing high-quality night photos
– Influence of minor shakes and movements on photo’s quality
– The need for long-exposure shots during night photography

3. Role of Smartphone Gimbals in Improving Stability
– Stabilization features offered by quality gimbals
– How gimbals correct shakes and unwanted movements
– Real-life examples of gimbal usage in night photography
– Comparison of the quality difference in photos captured with and without gimbals

4. Extra Features Provided by Smartphone Gimbals
– Additional benefits other than stability, like panoramic shots, motion time-lapse, etc.
– How these features can contribute to creative night shots

5. Overview of Noteworthy Smartphone Gimbal Models Perfect for Night Photography
– Discuss some top models and brands
– Compare their features, advantages and drawbacks for night photography

6. Use Case Scenarios: Professional vs. Amateur Photographers
– Explain the significance of gimbals for both categories
– Discuss different scenarios where various types of gimbals might be more useful

7. Practical Tips for Using Smartphone Gimbals in Night Photography
– How to get the best results using your gimbal
– Possible challenges and solution tips

8. Emerging Trends in Smartphone Gimbals Relevant to Night Photography
– Track the current trends in gimbal technology
– Predict future upgrades

9. Expert Opinions on The Essentiality of Smartphone Gimbals for Night Photography
– Cite experts in photography to share their perspectives

Remember, each of these sections might deserve at least 1000 words given how extensive the topic is. You can further divide the sections into sub-points to make them more comprehensive ensuring you touch all relevant dimensions of the topic. Situate keywords strategically within the content after having researched heavily searched relevant keywords. Use images and infographics to break up the text for improved readability.