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VR2VBU 發表於 26-2-2016 19:00:18

VR2VBU 於 2016年2月26日下午 18:00 接收 NOAA-15 氣象衛星

VR2VBU 發表於 6-3-2016 19:44:01

VR2VBU 在 3月6日下午 14:40 接收 NOAA 19 氣象衛星, 訊號 和 效果非常滿意

VR2UIO 發表於 7-3-2016 17:28:16

接收衛星訊號，是自我訓練的好方法之一。

VR2VBU 發表於 10-3-2016 18:58:49

本帖最後由 VR2VBU 於 10-3-2016 19:18 編輯

這是 3月6日來自 NOAA 19 氣象衛星訊號的音效檔案

VR2UIO 發表於 16-3-2016 17:28:05

NOAA19
Date: 20160306 Time: 0634 UTC

VR2GY 發表於 17-3-2016 13:39:30

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VR2GY 發表於 18-3-2016 11:31:06

NOAA卫星是美国国家海洋大气局的第三代实用气象观测卫星，第一代称为“泰罗斯”（TIROS)系列（1960-1965年），第二代称为“艾托斯”（ITOS)/NOAA系列（1970-1976年），其后运行的第三代称为TIROS--N/NOAA系列。中文名NOAA卫星所    属美国国家海洋大气局轨道高度870千米和833千米轨道倾角98.9°和98.7°1卫星参数NOAA的轨道是接近正圆的太阳同步轨道，轨道高度为870千米和833千米，轨道倾角为98.9°和98.7°，周期为101.4分钟。NOAA的应用目的是日常的气象业务，平时有两颗卫星运行。由于一颗卫星可以每天至少可以对地面同一地区进行两次观测，所以两颗卫星就可以进行四次以上的观测。2传感器NOAA??带的探测仪器主要有高分辨率辐射计（AVHRR/2)和泰罗斯垂直分布探测仪（TOVS).参数包括5个波段，可见光红色波段、近红外波段、中红外波段和两个热红外波段，如表2所示，其中*3a白天工作，3b夜间工作。NOAA-18卫星发射时间2005年5月11号，正式运行日期2005年6月26日轨道高度：854公里，轨道倾角：99.0度，轨道周期：102

VR2GY 發表於 24-3-2016 11:34:02

APTWeather Satellite Reception - Decoding and Display SoftwareOverviewAlthough expensive dedicatedinterfaces with accompanying software are available from commercial suppliersof weather satellite hardware, most enthusiasts these days decode the APT datafrom the NOAA satellites using their personal computer and itsassociated soundcard.
A number of dedicated amateur programmers have produced software packages thatcan be obtained either free, or for a very modest charge, and produce veryhigh-quality images indeed.
Program Author Details
Wxsat ChristianBock Wxsat is probably the simplest entry-level soundcard program. Wxsat candecode images in real-time. The program can simultaneously save the image asa bitmap and store the raw data as a WAV file for future decoding andmanipulation as the signal is being received.
Wxsat is freeware. A full tutorial on using this software is here.
JVcomm32 EberhardBackeshoff JVcomm32 is a multi mode program which can receive and decode weather charts,weather reports, NAVTEX and SYNOP messages, weather satellites, ham radioSSTV and FAX. NOAA weather satellite (FAX) transmissions are decoded intoimages in real time, and the images saved as bitmaps. A demo version isavailable, but JVcomm32 must be registered to create usable images.
WXtoImg CraigAnderson WXtoImg is a feature-laden program that decodes NOAA data in real-time, savingthe raw data as WAV files. The program can be made to process these WAV filesinto images in a variety of projections, and can create colour composites ofnumerous types. This is the most complex of the programs listed. To releaseits full power, registration is required, although the freeware version hasmore than sufficient features for the beginner.
APT Decoder PatrikTast APTDecoder is a another feature-laden program that decodesNOAA data in real-time, saving the raw data as WAV files and processing themboth monochrome and colour composite images. The particular advantage of thissoftware is that it is completely free.
SatSignal DavidTaylor Satsignal differs from the above programs in that it does not actually demodulateNOAA data transmissions. Satsignal has been designed specifically to createhigh-quality images from pre-existing WAV files created by programs likeWxsat and Wxtoimg. Satsignal boasts an impressive array of image enhancementtools (gamma, histogram, creating colour composites, sharpening, illuminationadjustment, cropping noisy lines etc.)
The basic version of Satsignal is free to use, but registration is requiredto unlock its full range of image processing tools.
SatScape ScottHather Satscape is primarily a fantastic satellite tracking program with a beautifullycrafter interface. But it also has a facility that enables it to record NOAAraw data as WAV files. Satscape can combine its tracking powers toautomatically 'switch on' WAV file recording when a satellite comes withinrange. These can subsequently be processed into images using Wxsat andSatsignal.
Displaying Your ImagesThe NOAA APT images you createcan, of course, be displayed by the above decoding software packages. However,if you wish to scan through a library of archived images, a dedicated imageviewing program is preferable.One of the best such programsis IrvanView, created by Irfan Skiljan. IrfanView is completely free,and is one of the most popular pieces of software of its type. It can view allthe common (and many uncommon) image formats and has an impressive 'slideshow'feature.

VR2GY 發表於 29-3-2016 01:30:06

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VR2GY 發表於 29-3-2016 18:09:52

StructureThe broadcast transmission is composed of two imagechannels, telemetryinformation, and synchronization data, with the image channels typicallyreferred to as Video A and Video B. All this data is transmitted as ahorizontal scan line. A complete line is 2080 pixels long, witheach image using 909 pixels and the remainder going to the telemetry andsynchronization. Lines are transmitted at 2 per second, which equates to a 4160words per second, or 4160 baud.
ImagesOn NOAA POES system satellites,the two images are 4 km / pixel smoothed 8-bit images derived from twochannels of the advanced very-high-resolutionradiometer (AVHRR) sensor. The images are corrected for nearly constantgeometric resolution prior to being broadcast; as such, the images are free ofdistortion caused by the curvature of the Earth.
Of the two images, one is typically long-wave infrared (10.8micrometers)with the second switching between near-visible (0.86 micrometers) and mid-waveinfrared (3.75 micrometers) depending on whether the ground is illuminated bysunlight. However, NOAA can configure the satellite to transmit any two of theAVHRR's image channels.
Synchronization and telemetryIncluded in the transmission are a series of synchronization pulses,minute markers, and telemetry information.
The synchronization information, transmitted at the startof each video channel, allows the receiving software to align its sampling withthe baud rate of the signal, which can vary slightly over time. The minutemarkers are four lines of alternating black then white lines which repeat every60 seconds (120 lines).
The telemetry section is composed of sixteen blocks, each 8lines long, which are used as reference values to decode the image channels.The first eight blocks, called "wedges," begin at 1/8 max intensityand successively increase by 1/8 to full intensity in the eighth wedge, withthe ninth being zero intensity. Blocks ten through fifteen each encode acalibration value for the sensor. The sixteenth block identifies which sensorchannel was used for the preceding image channel by matching the intensity ofone of the wedges one through six. Video channel A typically matches eitherwedge two or three, channel B matches wedge four.
The first fourteen blocks should be identical for bothchannels. The sixteen telemetry blocks repeat every 128 lines, and these 128lines are referred to as a frame.
Broadcast signalThe signal itself is a 256-level amplitude modulated 2400Hz subcarrier,which is then frequency modulated onto the 137 MHz-band RFcarrier. Maximum subcarrier modulation is 87% (±5%), and overall RF bandwidth is 34 kHz. On NOAAPOES vehicles, the signal is broadcast at approximately 37dBm (5 watts)effective radiated power.
Receiving imagesAn APT signal is continuously broadcast, with receptionbeginning at the start of the next line when the receiver is within radiorange. Images can be received in real-time by relatively unsophisticated,inexpensive receivers during the time the satellite is within radio range,which typically lasts 8 to 15 minutes.
As of 2004 there were almost 5,000 APT receiving stationsregistered with the World Meteorological Organization(WMO). It is unclear what percent of the total user-base this represents, sinceregistration is not a requirement, and was only available after 1996.
Radio receiverThe bandwidth required to receive APT transmissions is approximately34 kHz. Most older scanners (police and fire type receivers) are thestandard 15 kHz bandwidth which were designed to support voicetransmissions. Newer VHF general coverage receivers are equipped with multipleIF bandpasses; some are, but not limited to: 6 kHz, 15 kHz50 kHz & 230 kHz(broadcast FM). Use of a receiver with too narrowa bandwidth will produce pictures that are saturated in the blacks and whites,as well as possible inversion. Too wide, and the noise floor of the receiverwill be too high to acquire a good picture. For the amateur enthusiast, acomputer controller receiver is the best option to allow the software toautomatically tune and set the required modes for proper reception. There arealso dedicated APT receivers made specifically for computer control and APTreception. Specifically, ICOMPCR1000, PCR1500 & PCR2500 will produce excellent results. Searching on theweb for "NOAA APT (RECEPTION or RECEIVER)" will produce a wealth ofinformation on receivers, software, and antennas.
AntennaAPT images from weather satellites can be received with aright-hand circular polarized, 137 MHz antenna.Normally, there is no need to have the antenna follow the satellite and a fixedposition antenna will provide good results.
The two most frequently recommended antennas are the crosseddipole and the quadrifilar helix antenna (QHA).
Displaying the imagesYears ago,[when?] toreceive APT images, a specialized decoder was required in addition to thereceiver to display or print images, much like HF WEFAX (serving themaritime community). Often both receiver and decoder were combined into oneunit.
Today,[when?] withthe advent of personal computers, all that is required is dedicated software[which?] (many of which offer"free" versions) and a sound card. The sound card acquires anddigitizes the slow scan video (in the audible range) comingfrom the speaker, phones, or line-out of the receiver, and then the softwarewill process the various visible and infrared channels of the AVHRR sensor.Most software will automatically save every image and publish processed imageonto the website of choice, putting up a new image on every pass of an APTsatellite.
Enhanced imagesSince each channel of the AVHRR sensor is sensitive to onlyone wavelengthof light, each of the two images is luminanceonly, also known as grayscale. However, different materials tend to emit or reflectwith a consistent relative intensity. This has enabled the development ofsoftware that can apply a color palette to the images which simulates visiblelight coloring. If the decoding software knows exactly where the satellite was,it can also overlay outlines and boundaries to help in utilizing the resultingimages.

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