Estimate the total forest area of this county in year 2000 according to the forest area of 91 raster units of TM image of Heshun county in Shanxi province
Implementation steps:
- Calculate the mean of 91 sample pixels, then multiply 2,697,460, the result is the estimated total area;
- Estimate the population variance by sample data, estimate the sampling accuracy by population variance and sample size.
Calculate:
- Estimate the total forest area of Heshun county:
- Sampling accuracy:
of the forest area in pixel;
Confidence level
；
Sample value 
；
Total sample size
n；
All the image pixel size
N
n the re search areas
;
Sample variance