Download - EISCAT Facility update 2013
![Page 1: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/1.jpg)
EISCAT Facility update 2013
M. Kosch, Lancaster University, UK
M. T. RietveldEISCAT, Ramfjordbotn, Norway.
19th RF Ionospheric Interactions Workshop, 21 - 24 April 2013, Arecibo.
![Page 2: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/2.jpg)
Overview
1) EISCAT organisation and radar status
2) Heating status and recent results
![Page 3: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/3.jpg)
EISCAT Scientific Association EISCAT: Organisation
CAGCouncil Advisory Group
![Page 4: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/4.jpg)
New director: Craig Heinselman (since January 2013)
UHF (933 MHz) radar now monostatic only. GSM mobile phone network interference became too strong at Kiruna & Sodankyla. We are seeking licence extension beyond 2013.
VHF radar now tristatic: Kiruna & Sodankyla converted to 224 MHz. (But Tromsø remains non-field-aligned). Actually, it is tetrastatic, with the KAIRA receiver (LOFAR antenna at Kilpisjarvi, Finland) also receiving signals from the VHF radar.
EISCAT 3D: large funding proposals submitted by Norway and Sweden & hopefully Finland soon. Total cost estimate 132 M€. Core site selection still not decided, but near Ramfjordmoen, possibly further inland.
EISCAT news
![Page 5: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/5.jpg)
receiving antenna, 5.4-8 MHz
transmitting antenna, 5.4 – 8 MHz
4-5.4 MHz
![Page 6: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/6.jpg)
Heating Status, April 2013
Staffing:
One scientist plus one engineer.
Operations:
269 hrs in 2011, 263 hrs in 2012
Users from China, Finland, Japan, Norway, Russia, Sweden, UK, USA.
Publications:
13 in 2011, 6 in 2012, average about 10/yr which is about 20-25% of all EISCAT publications annually.
Heating Technical status:
Transmitters largely OK. One faulty transmitting tube is being rebuilt by Richardson Electronics (USA) to improve the spare part situation.
Array 1 (30dBi gain): Serious rot was found in many of the small wooden poles supporting the feed lines. This array was rebuilt in 1990 and so is showing its age in some areas. Non-treated wood was used in some areas (not the main masts) since a 30+ year lifetime was never envisaged.
Major upgrade work done in recent years on the RF generation, modulation and control hardware and software. Much greater flexibility, computer control of hardware and logging. For example instantaneous frequency/phase/amplitude stepping is possible.
![Page 7: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/7.jpg)
1975 1980 1985 1990 1995 2000 2005 20100
5
10
15
20
25
0
50
100
150
200
250
300
Publications from the Tromsø HF Facility (& HF hours)
Year
Pub
licat
ions
HF hours|
Heater starts
operationsTransfer
from Max-Planck to
EISCAT
![Page 8: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/8.jpg)
Maintenance required on some ageing parts in antenna fields- rotting wood.
![Page 9: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/9.jpg)
HF radar experiments with heating transmitters and Array-3 receiver in high demand: mostly low altitude (mesospheric) but also high-altitude (magnetospheric) experiments.
New hardware and software enables computer monitoring and control of certain transmitter hardware functions that were only available via lights and buttons on the console.
Fast frequency and/or phase and/or amplitude modulation is possible now.
Power calibrations and power stepping improved implementation.
Better logging of HF parameters.
Soon a modification to the coaxial switches will allow both reception and transmission on array-3 (5.4-8 MHz, 24 dBi gain).
Heater upgrade: developments and ongoing work
![Page 10: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/10.jpg)
These buttons/lights are now under computer control.
![Page 11: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/11.jpg)
Array-3 feed lines disconnected from transmitters
Using antenna array-3 as a receiver(presently with transmission line disconnected from
transmitter) Power combiners
![Page 12: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/12.jpg)
to transmitter
cable from tx/rx switch to power combiner or digital beam former
to antenna (array-3)
New receiver connection to antenna (without opening the co-axial lines) summer 2013
![Page 13: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/13.jpg)
Recent scientific resultsX-mode excitation of irregularities and HFILBackscatter enhancements on topside (very mysterious)Mesospheric HF echoes received in radar modeMesospheric VHF echo modulationD-region heating model overestimates heating measured by riometer and cross-modulation experiments.Novel API (Artificial Periodic Irregularity) experiments Efficiency of resonant heating calculated.Ion upwelling studies
![Page 14: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/14.jpg)
Modelling the beam pattern with EZNEC suggests that the non-perfect ground may result in the antenna gain and ERP being only about 75% of that calculated assuming a perfect ground. This may help explain some of the discrepancy beyween calculated and measured heating effects in the D region. (e.g. Senior et al., JGR, 116, A04310, doi:10.1029/2010JA016189, 2011).
Laying a ground plane of wires may be a relatively cheap way of increasing the effective radiated power. This is being investigated at present.
![Page 15: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/15.jpg)
8 MHz echoes shown as contours on lower plot
224 MHz echoes in colour with 8 MHz echoes shown as contours
Mesospheric echoes
![Page 16: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/16.jpg)
These apparent densityincreases are a mystery.
But they are not real andare only seen very close
to field-aligned
See the recent paper by Senior et al., 2013 for details, GRL
![Page 17: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/17.jpg)
Examples of ion upwelling in the last few heater pulses
(as well as the mysterious backscatter enhancements)
![Page 18: EISCAT Facility update 2013](https://reader035.vdocuments.us/reader035/viewer/2022062501/568166ef550346895ddb4945/html5/thumbnails/18.jpg)
Mesospheric velocities with API One advantage of the API method is that it allows high resolution vertical velocities to be measured between 50-120 km. Here is an example plot from our 9.12.2011 measurement. Around noon (7000 seconds in to the measurement) there are also some tropospheric echoes. -- from blog by Juha Vierinen: kaira.sgo.fi