N1SU APRS Digipeater Packet Propagation and Analysis

N1SU APRS Digipeater Packet Propagation and Analysis

Jason Buchanan, N1SU
N1SU-2 APRS digipeater is located in Issaquah, WA with general coverage to the northwest, mainly toward Victoria, British Columbia and stations between.


Digipeater Statistics

Text table showing packet count for a given day where N1SU-2 (144.390 1200) or N1SU-4 (440.800 9600) appears in the packet path, as retransmitted by a distant APRS station.

AG7WT-5, KI7JBV-5, N7RIG-5, and UCAPK operate on 440.800 UHF 9600 baud APRS.

DATE
SUM
AG7WT-5
AI7Z-10
ERINB
JUPITR
KB7SDM-1
KD7UBJ-1
N7IEI-1
N7RIG-5
TIGER
UCAPK
VE7SLC-7
WT0F-10
02/14
2
1
-
-
-
-
-
-
1
-
-
-
-
10/16
137
31
21
1
4
-
31
2
43
1
2
-
1
10/17
2
-
-
-
-
-
1
-
1
-
-
-
-
10/18
84
9
20
-
2
-
10
2
39
1
-
-
1
10/19
134
23
26
-
2
-
20
2
54
1
4
-
2
10/20
263
65
87
-
4
-
58
6
39
3
-
-
1
10/21
106
14
28
-
1
-
17
2
42
1
1
-
-
10/22
144
37
22
-
2
3
22
5
45
3
4
-
1
10/23
174
50
37
-
-
2
24
5
56
-
-
-
-
10/24
73
29
23
-
1
1
-
3
11
4
1
-
-
10/25
172
70
44
-
2
-
25
5
23
1
-
1
1
10/26
191
91
34
-
-
-
24
5
31
3
1
-
2

Absolute packet count

The first bar graph shows packet count for a given day where N1SU-2 or N1SU-4 appears in the packet path, as retransmitted by a distant APRS station. The bars are stacked in alphabetical order.




Proportional packet count

The second bar graph shows the same data but as a stacked histogram to show the relative percentage of a station compared to others for a given day.


Repeated Ratio is the ratio of packets that were repeated by a distant digipeater (see bar graphs) where the N1SU digipeater appears in the path of a packet containing one or more remaining hops.
Repeated Ratio of 1.00 indicates that each packet with one remaining hop transmitted by N1SU was retransmitted by a distant digipeater; likewise a ratio of 2.00 indicates two different digipeaters retransmitted the packet sent by N1SU.

The Repeated Ratio is a means to show the effects of changing TXDelay, RF output power, and other parameters.

Notable observations for supporting optimal communication with my setup (currently TNC-Pi, Icom IC-2200H):


About the graphs

The graphs on this page show APRS packet propagation where the N1SU digipeater appears in the packet path.
The source of this data is from the N1SU digipeater APRX log.
The data is not filtered or deduplicated.
The graphs are updated once a day (soon to be automated via cron).
The colors and stations are dynamically plotted - over time some will appear, or disappear.
Accuracy is correlated to the captured data over time, and isn't sourced from remote APRS stations.
Numerous factors can reduce packet count, including atmospheric interference, congestion and lack of Carrier Sense Multiple Access (CSMA), multipath, etc. 144.390 is very busy in Seattle.



Repeated packets from nearby repeaters

The following two heatmap images show received packet count:



This page is still being written/improved so please pardon errors, omissions, etc.


N1SU APRS Digipeater Packet Propagation and Analysis - Created: 3-Dec-20
(C) 2020 jsb@digistar.com

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