Case introduction

 

Sampling survey to the total area of the forest of Heshun county in Shanxi province in year 2000

 

Description:

We need to take some samples from 2,697,460 image units to investigate (the minimum investigated unit is a TM image) the area of forest coverage of Heshun county in Shanxi province in year 2000, require that presampling 20 samples before formally sampling, the presampling variance is 5000m2. According to the previous investigated results, the variance of the forest area of a TM image is 55m2.
 

Sampling method:

Systematic sampling

 

Objective:

To estimate the forest area of Heshun county in year 2000 by sampling

 

Condition:

  1. Presampling variance is 5000 m2;
  2. Presampling size is 20;
  3. The expected variance of the forest area pixel is 55m2.
 

Request:

  1. Optimal sample size, namely, the least pixel size to meet the requirement of sampling precision;
  2. Distribute the samples, namely, extract the pixel number that need to be investigated from the sampling box;
  3. Calculate, namely, estimate the total forest area and sampling precision according to the sampling pixels and investigated data.
 
 
 

     
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