# Midterm ## Significant figure 1. I am not going to be picky on this for equations using more than + - $\times$ $\div$. 2. For distance and error propagations, you can use the same significant figures in the known numbers, but use the one with smallest significant figures. ## Information for midterm Here is some information for midterm (It may be changed): 1. The exam will be online 2. All the questions are in multiple choices. The whole midterm will be graded automatically.-> **Update: Dr. Shan changed his mind so we have questions in all kinds of forms now.** 3. The questions are classified in 3 levels in terms of difficulty. 4. There are 50 questions and you have 120 min. You won't have much time looking for information online. 5. All TA will design questions and we are going to merge the new questions from TAs to a huge questions pool from last semester. Dr. Shan will select questions from the questions pool and make a new pool. (In my opinion, that means the new question pool may be more difficult than TAs' expectation) ## My personal opinion on preparing midterm Note that I haven't read the question pool. In fact, I won't write anything after reading the pool. Therefore, whatever written here is nothing but my own suggestion. 1. List the definition of all the terms and symbles used in this course. (The most important thing you should finish before the midterm) 2. Understand the error propagation. This concept is the most important concept in this course. You will need to use error propagation after the midterm. 3. Make sure you remember the steps of outlier detection, error propagation, differential leveling, 3 point resection, and traversing. You need to understand the meaning behinds each steps. 4. Compare different terms. e.g. precision/accuracy, raster/vector in GIS, sources of errors, datum/geoid, and all kinds of height in geodesy. 5. List all the formula in case you need to compute something. - error propagation of a+b+c - error propagation of distance - error propagation of mean - error propagation of total station computation - Relationship between heights in geodesy 6. **Read the textbook**