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...ttingen. 164 S.</ref>). In some situations it is useful from a statistical point of view, or required for practical and organizational reasons, to subdivide ...e can achive a higher [[accuracy and precision|precision]] with the same [[sample size]]. Beside statistical issues there are further arguments for stratific

*Die räumliche Verteilung von zufällig gewählten [[Lecturenotes:Sample point/de|Stichprobenpunkten]] ist gleichmäßiger über die Grundgesamtheit verte ...tes:Allocation of sample points/de|Allokation]]) der [[Lecturenotes:Sample point/de|Stichprobenpunkte]].

... property that we can identify every single element and include any in our sample. ...ing frame, should be clearly defined for any sampling study. Reasons for a sample frame that is smaller as the population is for example, that parts of the p

...nse) and remote sensing application to forest monitoring (regionalization, sample based application of LiDAR data). At the core of this research is the analy ...itable methodology for linking area-wide remote sensing data (RapidEye) to sample based remote sensing data (LIDAR),

==The concept of cluster selection zones for fixed area sample plots== ...sible sample points, the jigsaw puzzle is a classification of the infinite sample frame in a finite number of areas of possible observations. This number of

... elongated rectagular plots might be more suitable from a pure statistical point of view! ... (describe how [[Sampling intensity vs. sample size|sampling intensity and sample size]] are affecting [[accuracy and precision|precision]])

...y resources available to measure <math>n=10</math> sample plots. The small sample size led to a fairly high value of the estimated [[error variance]]. ...lots of 25 m x 25 m out of each original plot. By that, you increase the [[sample size]] to the fourfold and, thus, reduce the error variance.

... The relation of the section ''hi'' to line ''hk'' is 1:10. the height of point ''i'' corresponds to 1/10 of the tree height. In order to calculate the tre ...ngle opening. Trees with width smaller than ''fg'' are not included in the sample (counted).

... only necessary if you really whish to measure the distance exaclty to the point where the transponder is fixed), ===Distances within a sample plot===

...[[Lectuenotes:Sampling design and plot design|response design]]: The major point in cluster sampling is that for each [[random selection]] not only one sing ...ry, it is common that not single compact plots are laid out at each sample point but clusters of sub-plots. There, sub-plots are laid out in various geometr

...Note: | text=The lack of randomization cannot be compensated by increasing sample size!}} ...imulate a random selection on a map by closing the eyes and pointing to a point in the map. Because the guarantee is not given, that, when doing that very

...l elements is following a systematic pattern. Examples are square grids of sample points laid out over an area of interest; or the selection of every 10th tr ...of numerous sub-plots – that is, all the sample points on the systematic sample are strictly spoken sub-plots of one single cluster that is spread out over

... the only way is to very often repeat the [[systematic sampling|systematic sample]] and calculate the variance of all the estimations produced; that is then ...eatedly) random pairs out of the <math>n</math> elements of the systematic sample and calculate the difference for each of the pairs, we would expect the exp

...re, the correlation to the ancillary variable is also used to reduce the [[sample size]] in the second phase <ref name="kleinn2007">Kleinn, C. 2007. Lecture ... variable is observed. In the case of independent phases, the second phase sample has nothing to do with what had been sampled in the first phase. In that ca

...e which has a radius that corresponds to the distance between the [[sample point]] and the <math>k^{th}</math> tree. Depending on the distance to the <math>

...nits]], just as we may use for many purposes fixed area [[fixed area plots|sample plots]] (two-dimensional observation units) or points (dimensionless observ *It may be observed which portion of a sample line comes to lie in forest. These portions can be used to estimate the [[F

... target variable requires knowing the entire population. Then, there is no point in sampling. We, obviously, need to find an ancillary size variable of whi | align="left" colspan="3" | '''Figure 1.''' Sample population

...pectively. From this set of N sections we would then select n sections as sample. ...S) is a sampling strategy that facilitates the drawing of a probabilistic sample without ''a priori'' defining the sampling frame. The inclusion probabilit

...94ff </ref>). It is some times also referred to point sampling, horizontal point sampling, variable plot sampling, angle count technique, prism cruising, an ...). This is exactly what Bitterlich sampling does: from a selected [[sample point]], the neighboring trees are selected strictly proportional to their [[basa

...elements (e.g. a number of trees included by a sample plot) is selected as sample. ...cal population of trees. Sampling in forestry is based on the selection of sample points and not trees. Afterwards an observation is derived by including tre

...s the status''' of the relationship between ''dbh'' and height for a given point in time. '''It is not a growth curve'''. It can, therefore, not be used to ...all sample trees, but height only for a small sub-set, for example on each sample plot the one or two trees closest to the plot center are height measured. F

... sample trees that are within a defined distance (radius) from the sample point, which constitutes the plot center (Kleinn 2007<ref name="kleinn2007">Klei ... Those trees are taken as sample trees in whose inclusion zones the sample point comes to lie (Kleinn 2007<ref name="kleinn2007">Kleinn, C. 2007. Lecture No

...o lie close to the [[Forest Boundary|forest boundary]] so that part of the sample plot slops over. Of course, if this is not taken into account, an error is ...ce a systematic error. [[Plot shifting]] is – from a strict statistical point of view – never permitted. Using option D in Figure 1, one needs to tak

... (observer bias). A systematic error cannot be compensated by increasing [[sample size]]. ...bability sampling]] approach (or [[plot design]]). Trees are included in a sample, if they appear bigger that a defined opening angle. Basal area can be esti

..._vilcko2006">Kleinn C. and F. Vilčko 2006. Design unbiased estimation for point to tree distance sampling. Canadian Journal of Forest Research 36(6):1407-1 ...e (e.g. the radius of a circular plot up to which trees are included in a sample) is defined, here the number of included trees per sampling location is fix

.... Consequently, the [[population]] from which we sample is a population of sample plots. ... sample plots of identical shape and size, here: square and hexagonal sample plots. Such a subdivision is also possible for rectangles and some types

...xed plot area ''a_k'' for an expected number of ''k'' trees per sample plot is ...math>. The variance of the estimated mean <math>\bar y</math> for a random sample of a given size n follows then from

Estimations are the principal result of sampling studies. All results of a sample are estimations and must be interpreted as such; they help us to learn some |sample based estimation

...ean at point 2 in time and <math>\bar{y_1}</math> is the estimated mean at point 1 in time. The estimated change is a linear combination of two random vari ...ent randomizations were done, and, therefore, different [[Fixed area plots|sample plots]] selected. The change is estimated then along <math>c=\bar{y_2}-\bar

...t is simply counted how many points fall into forest; if, out of the total sample size ''n'' there are <math>n_f</math> forest points, then the forest cover which is the parametric variance. The sample based estimation of that variance has <math>(n-1)</math> degrees of freedom

...mple based estimation either in remote sensing imagery or from terrestrial sample plots. ... 2005 October 3-6, Portland, Maine. Program and Abstracts: 78.</ref>) uses sample based forest edge length estimates to characterise forest edge-interior fra

...n. It is more probable that there are various very good options. The major point is to avoid pitfalls and errors, and that is best done by consulting with e ...teams do exactly the same. Some more points about this extremely important point are discussed in the following;

...oned glass plate that is used to make an [[Bitterlich sampling|angle count sample]]. You can estimate [[basal area]] with [[Bitterlich_sampling#Choice_of_bas ...ple]] moving around the prism – while the prism is located at the sample point.

Based on a coherent network of [[Fixed area plots|sample plots]] distributed over the total [[forest Definition|forest area]] of the ===Extension of the monitoring concept using a systematic grid of sample plots===

...uracy assessment we need an additional independent reference data set. The sample size should be large enough to divide the reference data into training and # Generating sample points

...nuals on the [http://cran.r-project.org/ R website]. Another good starting point is the [http://www.statmethods.net/ Quick-R website].

...ny methodological framework that helps to make use of the data sources for sample based estimation. Depending on the available spatial resolution of images, ...stance of points is constant along the latitudes. Here a global GSG with a point distance of 250km is shown in a cylindrical map projection.

# Type in the search bar {{typed|text=Point sampling tool}}, click on the plugin name and then on {{button|text=Install # Load the regular grid as vector point file ''systematic_grid100.shp''' created by [[Creating regular grid]].

...m-in to the points and click on a land cover/use pixel associated with the point attribute to create a ROI. ...d '''Max''' as 30. Click the button {{button|text=Redo the roi at the same point}} [[File:Redo.PNG]] to capture more spectrally similar pixels.