I. INSTRUMENTATION
A. Vertical Sounding
The IPS-42 Digital Ionosonde replaced the C-3 analog film-recording ionosonde. The sweep frequency is from one to 15 MHz. the ionosphere directly overhead is probed twice a day.
B. Trans-Equatorial or Oblique Ionosonde
Signals transmitted across the equator from MO and received in several southern stations reveal the changing characteristics of the equatorial ionosphere. The sweep frequency is from 17 to 70 MHz. The transmission is four times an hour all day. this is a cooperative work between MO and DSTO of Australia.
C. Ionospheric Tomography
Signals from a set of satellites, the precursor of the GPS system, are simultaneously received by six stations along the 120 degree east meridian. Two are in Mainland China, two are in Taiwan and the remaining includes the MO stations of Baguio and Manila. To be determined are the morphology and dynamics of the equatorial ionosphere, in particular, the equatorial ionospheric anomaly. This cooperative work is between Wuhan University in Mainland China, National Central University in Taiwan and MO.
The original tomographic equipment used removable optical disks with two-Gigabytes capacity for reading programs and writing data. However, dust and mold accumulating on their surfaces made them useless. Fortunately at this very time, large capacity low-cost optical hard disks became available. The program was modified so that hard disks replaced the optical disks. Hard disks have faster writing and retrieval rates and are much cheaper. The optical disk was considered as the ultimate storage media, so their high cost was justified during the design period. The high humidity of the Philippines may not have been foreseen.
The method of sending large amounts of data to Taiwan has been improved and optimized. Data handling, retrieval and storage can be done faster.
D. Fluxgate Magnetometer
The instrument runs 24 hours a day to measure the effects of the equatorial electrojet. The computer program was corrected for continual recording. The amount of data recorded is about 50 Megabytes per month. data has to be downloaded every month since the geomagnetic data recorder has only 80 Megabytes capacity.
II. COMPUTERIZATION
A. Staff Computer Skills
The staff became more skilled in computer use. They gained familiarity with the different programs developed last year and in software capable of graphing. Upgrading was done on some program modules like the Ionogram Dumping, Scaling, Data Entry, Ionospheric Data, Magnetic Data and Data Retrieving Modules.
B. Generic Data Retrieving Module
A new and more versatile data retrieving module was developed. this was used to extract Spread-F occurrence, Sporadic E and other ionospheric parameters. The module uses Macros and @Function formulas in the three-dimensional Lotus spreadsheet to detect the occurrence of desired phenomena.
C. Archiving/Data Storage
Archiving and data back-ups were done using two media, the 4mm 2-Gigabytes DDS Data Cartridge tape and the 150-Megabytes Data Cartridge for the Sytos Tape Drive. PKWare software not only copressed the files but made file transfers very fast.
1. Ionograms
One thousand five hundred digital ionograms were generated monthly. the files were compressed and stored in the Digital Data Tape.
2. Ionospheric Data and Magnetic Data
Files contaning numeric data were scaled manually from the ionograms. Aided by computer programs, these were compressed and stored in Digital Data Tape.
3. Tomography Data
Manila and Baguio data were compressed and transferred to 4mm Data Tape.
4. Fluxgate Magnetometer Data
The magnetic data were compressed in five-day batches. since the data involved at least 5,000 files per month, it took about 4 hours to compress and transfer them to the 4 mm Data Tape.
4. 4 MM Data Tape
One copy of the 4 mm Data Tape was sent to Taiwan and another kept there.
III. RESEARCH ACTIVITIES
A. Database Build-Up
The database was expanded to cover two decades of ionospheric data. Data from as far back as 1955 were encoded. Also encoded were the monthly ozone data from PAGASA that cover the period 1980 to 1994. The geomagnetic database was likewise expanded.
B. Research
Efforts were taken to determine the relation of the ionosphere with environmental concerns. the availability of the ozone data covering the current sunspot cycle that started in 1986 made possible correlation studies with sunspot numbers and ionospheric parameters such as foE and foF2.
Several graphical methods were tried in order to bring out diurnal, seasonal and other patterns, including correlation with ozone and suspot data. Various three diminsional graphical color presentations of monthly medians of foF2 for 27 years were also employed.
IV. MAINTENANCE AND REPAIRS
Damage due to lightning was minimized due to a better grounding system. The tomography antenna was repaired due to water seepage. A bigger coax cable resulted to increased satellite signal gain.
V. PUBLICATIONS
Digitized data and f-Plots were sent only to the World Data Center A (WDC-A) in Boulder, Colorado. Agencies that formerly received printed data from us can now obtain them from WDC-A. To copies of the 1995 ionospheric data were preinted and book bound for the MO Library.
VI. STAFF DEVELOPMENT
In addition to in-house skills upgrading, the Staff took the special course on digital interfacing at the Ateneo Computer Science Department. the staff attended a Remote Sensing seminar at the University of Asia and the Pacific. They participated in retreats in markina and Tagaytay.
VII. FUTURE WORK
A. Ultraviolet Radiation Project
- Development of low-cost UV-B radiation sensors
- Development of low-cost data loggers
- Deployment of these instruments at various latitudes and altitudes in the Philippines
- Determination of meteorological parameters at the same time and locations
- Determination of columnar ozone
- Analysis of the abovementioned data
B. Continuing Ionospheric Research
- Atlas of low-latitude spread-F ionograms
- Correlation analysis of spread-F and total electron content
- Correlation analysis of spread-F and solar cycles
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