The EHR reporting period for new and returning participants attesting to CMS is a minimum of any continuous, self-selected, 90-day period. Eligible hospitals and CAHs must successfully attest to avoid a downward Medicare payment adjustment.
As we saw previously with nominal and ordinal data, frequency distribution presents a summary of the data in a table, allowing you to see how frequently each value occurs (either as a count or a percentage).
Every 10 minutes the Advanced Meteorological Imager (AMI) instrument on-board GK-2A carries out a full disk observation. This process captures Earth in 16 different wavelengths of light, four of which are visible light. The remaining 12 wavelengths are various combinations of near-infrared and medium/long wave infrared.
Shortly after the observation completes, the resulting thermal infrared full disk image is transmitted via the LRIT downlink. A total of 144 full disk images are transmitted each day which is more than enough to create smooth animations such as the ones below.
Images not directly derived from GK-2A sensor data are also transmitted between full disk images. These include synoptic charts (surface pressure), sea temperature charts, swell forecasts and sea ice maps.
The RTL-SDR Blog has written a thorough guide for setting up the hardware required for receiving images from GOES-16/17 and GK-2A. An outline of the hardware setup is included in this guide but for full details I recommend following the RTL-SDR Blog guide linked above.
Initially xrit-rx may appear to be doing nothing, but if the console output includes "[VCID 63] GK-2A: IDLE" then the LRIT downlink is successfully being received and xrit-rx is waiting for an image transmission to start. For precise image transmission times see the LRIT Schedule on the xrit-rx dashboard (see below).
The Fourier transform takes us from the time to the frequency domain, and this turns out to have a massive number of applications. The fast Fourier transform (FFT) is an algorithm for computing the DFT; it achieves its high speed by storing and reusing results of computations as it progresses.
A signal with changing frequency is generated. This signal is transmitted by an antenna, after which it travels outward, away from the radar. When it hits an object, part of the signal is reflected back to the radar, where it is received, multiplied by a copy of the transmitted signal, and sampled, turning it into numbers that are packed into an array. Our challenge is to interpret those numbers to form meaningful results.
Thus, if we multiply the received signal by the transmitted signal, we expect two frequency components to appear in the spectrum: one that is the difference in frequencies between the received and transmitted signal, and one that is the sum of their frequencies.
Recall that the radar is increasing its frequency as it transmits at a rate of S Hz/s. After a certain amount of time, t, has passed, the frequency will now be tS higher (FigureÂ 4-10). In that same time span, the radar signal has traveled d = t/v meters, where v is the speed of the transmitted wave through air (roughly the same as the speed of light, 3 Ã 108 m/s).
Here, we generated a synthetic signal, vsingle, received when looking at a single target (see FigureÂ 4-11). By counting the number of cycles seen in a given time period, we can compute the frequency of the signal and thus the distance to the target.
A real radar will rarely receive only a single echo, though. The simulated signal vsim shows what a radar signal will look like with five targets at different ranges (including two close to one another at 154 and 159 meters), and vactual(t) shows the output signal obtained with an actual radar. When we add multiple echoes together, the result makes little intuitive sense (FigureÂ 4-11); until, that is, we look at it more carefully through the lens of the DFT.
First, we take the FFTs of our three signals (synthetic single target, synthetic multi-target, and real) and then display the positive frequency components (i.e., components 0 to N/2; see FigureÂ 4-12). These are called the range traces in radar terminology. 2b1af7f3a8