With the vigorous development of the GIS industry in recent years, GIS applications have penetrated into more and more industries.
Based on a GIS system with high-definition satellite images as base map, and then loading various industry data on this basis, and developing industry-related business functions, it is more conducive to improving the practicality of business functions and business data. Analysis presentation and program decision-making, etc.
However, GIS is also a field with certain technical thresholds. Judging from the users we have contacted from all walks of life, just loading a satellite image base map has made many users successfully fall into the trap.
In fact, we have already stepped through this pitfall for you!
The pit we stepped on for you
If you want to display your industry data and business functions on high-definition satellite images, you need a GIS system as the basis.
Although there are many GIS open source platforms now, each has its own advantages and disadvantages. If you have almost no experience in GIS, there will be a certain learning cost, and you may inevitably encounter some pitfalls.
Here, we will only talk about a pitfall in loading high-definition satellite image tiles that we encountered when developing GIS systems for customers.
Among the customers we have met, many users need to hash and store massive satellite image tiles, that is, store each tile as an independent file.
We also did this when we undertook some GIS projects a long time ago. Since the amount of tile map data at that time only involved one city or one county, the problem was not highlighted at first.
Until we needed to load data from several provinces in a project, we encountered a series of problems such as slow loading of map tiles, slow copying of map tiles, and inconvenient map update and maintenance.
We have also tried to use various databases to store tiles before calling them. Although the efficiency has improved, we still cannot satisfy customers.
Seeing the project acceptance date approaching day by day, those days of extreme suffering are really fresh in my memory.
But fortunately, after rounds of repeated attempts, we finally designed a method that is convenient for massive data storage.
Combined with the developed efficient retrieval algorithm, its smooth loading effect finally won the satisfaction of users, and the project finally passed the acceptance!
Have you ever experienced that feeling of hanging on by a thread and narrowly escaping death?
It can be said that once bitten by a snake, you will be afraid of well ropes for ten years.
From now on, whenever a user wants to store massive satellite images in tile format, we will communicate with them carefully about the problems they may encounter. What is gratifying is that almost all users readily accept our suggestions. We I am always grateful for everyone's trust.
What needs to be emphasized here is that it does not mean that tile hash storage is completely wrong, but when the amount is too large, it is easy to encounter efficiency bottlenecks!
Just imagine, if each map tile is compared to a book, the hashed map tile is like the books in the library are not put on the bookshelf, but just thrown to the ground. If you want to start from How long does it take to find the one you want in this pile of books?
Although map tiles are numbered and regular, when the number of tiles reaches a massive level, it will inevitably lead to low loading efficiency, resulting in stuck and unsmooth map display.
Of course, you can completely offset the problem of low retrieval efficiency by increasing investment in hardware equipment, using high-speed hard disk storage, and using expensive CPU, motherboard and other hardware.
Although the problem is solved, it is not the most economical and in my opinion highly undesirable.
Wouldn't it be great if we could achieve efficient retrieval and loading on relatively common hardware devices and make the map display smoother through better storage methods and more scientific and reasonable algorithm design?
First, the hashed satellite images are packaged into multiple files in an orderly manner. Each file is equivalent to a bookshelf in the library.
Then, through efficient retrieval software algorithms, while greatly improving the tile loading efficiency, it is also extremely convenient to update and maintain massive map data, because we can replace the entire file with another new file without loss.
The mass storage and retrieval technology of this satellite image does not rely on any database or third-party plug-ins. We use this technology in all products of Shuijingzhu.
Based on the experience summary of this technology, we specially applied for an invention patent called "A Map Drawing Method Based on Tile Maps".
Recently, the patent certificate for this invention has been issued. Here is a brief sharing with you.
Invention patent for "A map drawing method based on tile maps"
The invention patent certificate for "A Map Drawing Method Based on Tile Maps" is shown in the figure below.
Invention patent certificate first page
Second page of invention patent certificate
The detailed information of the invention patent "A Map Drawing Method Based on Tile Maps" is shown in the figure below.
Invention patent details
write at the end
Shui Jingzhu has been engaged in the GIS industry for many years, and has encountered many pitfalls. We are also constantly summarizing experience and applying these experience technologies to products. From time to time, we will also summarize some experiences into documents to share with you!
Every industry has its own experience and tips. Sometimes your so-called epiphany may just be someone else’s basic skills. 99% of the problems you encounter may have been solved by others. We can only strengthen mutual learning and communication. , in order to encourage each other to accumulate experience faster and make faster progress!
You have an apple and I have an apple. If we exchange it, each of us will still have an apple. You have an experience and I have an experience. If we exchange it, each person will still have two experiences.
We hope that some of the experience summaries or GIS resources we share from time to time can help you avoid detours in GIS-related work. We also hope that you will not hesitate to share your valuable experience with us.
Looking forward to your sharing!