Apllication assessment of multi-level Remote Sensing and multi source informationin theinvestigation of forest resources
You Xianxiang, Cui Saihua, Peng Fengju
Beijing Forestry University
Abstract
Image of remote is sensing is the means of transmitting messages Different levels and different information sources have different admit ability to transmit information in this paper the aspects of the extraction of different information geometric accuracy classification accuracy and applied potential were studied including space remote sensing (MSS, TM, SPOT, national land resource satellite), different kinds of air photos (color infrared photograph, panchromatic photograph), with different scales (1/130,000, 1/70,000, 1/30,000, 1/20,000, 1/8700). The application ability of the above items in the investigation of forest resources was evaluated.
Classification method and accuracy analysis about MSS TM SPOT and Chinese Territory Satellite (CTS)
The investigation of forest resources lies mainly in checking the quantity and distribution feature of the resources and mastering types of forest vegetation spices of trees types of stand and state of growth. The various data of quantity and quality of land suitable for forest are also to be collected for this purpose enhancement filter and information extraction of different vegetation indices were used and then optimum band combination was conducted for national land resources land resources image only optical amplification treatment was carried out.
Table 1 shows the automatic classification results of MSS combined image after enhancement the classification results of TM combined image after the processing of equalized D-value and the second principal component and NIR/RED the classification results of SPOTI combined image after the processing of Fourier transformation ratio and enhancement the classification results of SPOT2 combined image after piece wise linear stretching these methods are used because the effect of classification is good.
The interpretation ability of the applicable part image and the color image taken with national land resources satellite of the applicable part image can be known by comparison with TM and SPOT images in the following table.
Table 1
Comparison between the interpretation properties of (CTS)
and that of TM image
| LAND TYPE |
TM |
CTS |
| FIELD AND VALLEY FIELD |
Block distribution of a large place of field can be clearly distinguished color of crops in the field can be distinguished sore clearly than that of a place of national land but texture of the former is not so clear as that of the
letter |
Border of the field can be distinguished the block of the field that can be distinguishedis much smaller than TM the sate of growth of crops can be distinguished the advantage of block empty land and two row field and two row field shelter forest net meatiness not easily distinguished on TM images is even greater than that pf SPOT satellite in terms of distinction of filed shelter forest net. |
| SLOPING FIELD |
It can be distinguished only from color and cannot be directly interpreted there is no border line of sloping field it is not easy to distinguish from sparse grass
land. |
The border line of sloping field can be distinguished there is distinct texture structure but add pieces of small blocks are not easy to difference. |
| SPECIES |
On normal combination image some species are not easy to distinguish but most of the on enhancement image can be different such as populus the robinia and brush small they are easy to
mis- differentiate |
On color photo of national land resource satellite species are more easy to different mainly in the aspects of color texture and law of distribution brush is easily distinguished from tree but on black white picture be higher than TM image easy to differentiate. |
| CanOpy Density |
On TM color combination image denseness can be different from sparseness but separable grades are limited |
In the aspects of texture structure homogenous degree distribution and color canopy density can property be divided in to several grades interpretation of canopy density can be higher than spot image |
| GRASSLAND |
Larger pieces of grassland can easily be distinguished ones can be distinguished only in the aspect shade of color but easy to mis distinguish such as from on color different it is more grassland can be different but it is more difficult to differentia the grades of grassland on color combination image on the photo of national |
Sealer area of grassland can be distinguished to texture structure and color grades of grassland can also be interpreted. |
| TREES PLANTED ON FOUR SIDES |
Tree planted on four sides are not easy to distinguish expect for this planted incites and towns |
Tree planted on four sides of smaller villages can be distinguished trees planted on four sides of large villages are easy to distinguish. |
| ROAD |
The main artery is visible it is difficult to distinguish the branch line the main artery in hilly area is easy to
break. |
Both the main artery and branch line can be distinguish the cart road can also distinguished |
| CITIES AND TOWN RESIDENTIAL POINTS |
Average cities and town can be distinguished but streets in countries aren't easy to distinguish small villages are not easy distinguish
either. |
The main streets cities and towns can be distinguished most small villages can be distinguished the interpretation property is higher than SPOT image |
| SMALL RIVER BODY OF WATER |
The average small branch valley is not easy distinguish the small reservoir in the gusty some times is not easy to distinguish
either. |
The average small branch valley can be distinguish the small reservoir can also be distinguished.
|
Others such as the distinction of geomorphic feature and corrosion valley and the interpretation property of color image taken with national land resources satellite are also higher than TM image but in the aspects of providing image processing color mixture combination of wavebands and geometric accuracy the advantages of TM image are much greater than national land resources Satellite.
From above comparison it can be seen that MSS classification accuracy is the lowest TM lies between MSS and SPOT in classification accuracy in the 3 methods the classification accuracy of all residential points in the hilly area is low forest land in the complete forest area has higher classification effect sloping field terraced field bare land grassland are easy to mis-differentiate Yet the interpretation ability in the middle part of national land resource satellite image is higher than SPOT and TM.
The above experiment proves that because different information sources have different spatial resolving ability different spectrum resolving ability and different wavelength scope and band combinations there is different classification accuracy.
